US20040053011A1 - Document structure with circuit elements - Google Patents

Abstract

A method for forming a document includes the steps of (1) selecting a marking medium that has a pre-determined machine-readable characteristic, and (2) selecting a document substrate that is compatible with the pre-determined machine-readable characteristic of the selected marking medium. An information symbol is secured to the selected document substrate. A security layer which includes the selected marking medium is also affixed to the document substrate so that the security layer is in at least partial register with the information symbol. The method can further include the step of affixing a blocking layer to the document substrate in at least partial register with the information symbol. The blocking layer can be affixed to the document substrate so that blocking layer is intermediate the information symbol and the security layer or so that the security layer is intermediate the information symbol and the blocking layer. Inks that can be printed with conventional printing methods, such as intaglio printing, screen printing, relief printing, planographic printing, letterpress printing, and flexographic printing, are especially useful as any of the selected marking media. The ink used is chosen for a particular machine-readable characteristic such as dry-state conductance, fluorescence, optical density, reflectance, and scattering. For example, an ink which has a known, measurable conductance in a dry-state can be used to print conductive layers on the document which serve as security layers.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation-in-part of U.S. Ser. No. 08/794,120, filed Feb. 3, 1997, which was a continuation in part of U.S. Pat. No. 5,599,046, filed Jun. 22, 1994 and issued Feb. 4, 1997.[0001]
FIELD OF THE INVENTION
• This invention relates to the filed of document structures and printing methods, and more particularly to document structures and methods of printing documents having machine readable security information and security features.[0002]
BACKGROUND OF THE INVENTION
• It is often desirable to obtain information from documents in addition to the human readable information printed on the surface of the document. For instance, documents of many types are susceptible to tampering, alteration and counterfeiting. Lottery tickets for probability games are an example of a document which is particularly susceptible to tampering. A probability game lottery ticket normally has play areas, each containing play indicia covered by an opaque material, for example a latex material. To play the game, an individual scratches off the latex covering a specified number of the play areas to reveal the play indicia underneath. The player then determines if the combination of revealed play indicia is a winner such as the play indicia are all the same symbol or add up to a winning number.[0003]
• Part of the popularity of such probability games is derived from the fact that each and every ticket is a potential winner. If a player has lost, that at least one winning combination is present. Consequently, this type of game is generally perceived by lottery players as being more legitimate than other types of instant lottery games.[0004]
• The fact that every ticket is potentially a winner also invites players to tamper with the tickets. Because every ticket can win if the right play areas are selected, some players look for ways to determine the play indicia contained in every play area in order to identify the location of a winning combination. If the player can conceal the fact that he has seen the play indicia, the player subsequently can remove the latex covering from the play areas containing the winning combination and claim a prize.[0005]
• One technique used to accomplish this result involves lifting the latex to look at the play indicia before gluing the latex back into place. Typically, probability game lottery tickets are validated by the visual observation of a human lottery agent. It can be difficult to visually detect this sort of tampering. Thus, probability game lottery tickets are particularly susceptible to fraudulent tampering and because no effective way of preventing or detecting such tampering has been developed, probability lottery games have not become commercially successful.[0006]
• A second threat to the integrity of a document is the intentional alteration of its contents. For example, an individual may try to alter the information on a driver's license, contract, test answer form, invoice or inventory form. Such an alteration may involve the changing of a number in the document by removing the original number and inserting a new number. In the case of laminated documents, such as drivers licenses, the document can be delaminated and the driver's photograph can be replaced with the photograph of another person and the license relaminated. Such alterations can be very difficult to detect, especially if there are no other copies of the document.[0007]
• A third type of problem posed in the document security context involves counterfeiting. Rather than altering an existing document, the counterfeiter actually creates a document and attempts to pass it off as being genuine. Thus, paper currency, tickets, tags, and labels are often counterfeited and proffered as the real thing. The magnitude of this problem has substantially increased with the advent of the color photo copier.[0008]
• For example, the owner of a trademark might sell t-shirts bearing that trademark to increase the value of the shirt. In an attempt to thwart pirates, the trademark owner might also attach a identifying tag to the t-shirts. This makes it easier to determine whether a given t-shirt is genuine. In order to disguise the fact that t-shirts are counterfeits, a counterfeiter will reproduce not only the t-shirt's design, but also the tag. While being forced to create a similar looking tag will increase his costs, if the value of the trademark is sufficiently high, the counterfeiter will continue to attach a counterfeited tag.[0009]
• There have been a number of techniques developed to improve the security of printed documents including the addition of magnetic materials to the document which are magnetically encoded with information that can be used to verify its authenticity. However, magnetically encoded information can in many instances be easily detected, read and altered and thus is not always suitable for verifying the integrity of a document and as such is generally not suitable for lottery tickets and probability tickets in particular. Another disadvantage of magnetically encoding information on a document, is that alterations to the magnetically encoded information are not generally detectable. Other methods for verifying the integrity of lottery tickets have been used such as inks that change color when tampered with but none of these methods have been sufficiently secure to permit the commercial sale of probability tickets.[0010]
• There have also been a number of techniques developed for using electrical circuits in documents to represent information. See for example U.S. Pat. Nos. 3,699,311, 5,471,040 and 5,484,292. However, these documents suffer from a number of disadvantages including being expensive to manufacture and the delectability of the circuits in the document.[0011]
• Hence, it is desirable to provide an improved system for obtaining information from documents to discourage tampering, alteration and counterfeiting.[0012]
SUMMARY OF THE INVENTION
• It is therefore an object of the invention to provide a document structure and method of printing same that will provide for increased security as well as permitting information to be automatically read from the ticket.[0013]
• Another object of the invention is to provide a lottery ticket structure and method of printing same that will result in a lottery ticket having sufficient security to be used as a probability ticket.[0014]
• A further object of the invention is to provide a game ticket which includes a substrate, play indicia printed over the substrate and a scratch-off coating covering the play indicia which includes at least one electronic circuit element printed in conductive ink on the ticket. The electronic circuits can be printed over the play indicia and beneath the scratch-off coating. To improve security, the ticket includes an opaque blocking layer having a conductivity less than the circuit element. In this case, the game ticket can also include a seal coat applied over the play indicia and a release coat applied over the seal coat and below the electronic circuit elements to facilitate the removal of the electronic circuits when the scratch-off coating is removed or tampered with.[0015]
• An additional object of the invention is to provide a game ticket that includes a substrate, an integrity electronic circuit or circuits printed on the substrate, a primer layer printed over the first electronic circuits, play indicia printed on the primer layer, seal and release coats printed over said play indicia and a scratch-off coating printed over the release coat. An printed indicia electronic circuit or circuits can be located between the seal and release coats over the play indica. One or more opaque blocking layers can be printed between the substrate and the scratch-off coating. Also, in the case where a bar code is printed on the lottery ticket, the integrity electronic circuit can be located underneath the bar code and extend to one or more of the play indicia.[0016]
• Another object of the invention is to provide a game ticket having a substrate, a number of play indicia and a circuit element printed over the paper substrate having two capacitive pick-up areas connected by a resistive element where the resistive element is located under the play indicia. The resistive element can be printed with two layers of conductive ink. Also, the resistive element can be configured as a serpentine track.[0017]
• Yet another object of the invention is to provide a document having a paper substrate, a number of play indicia, a printed circuit element having two capacitive pick-up areas connected by a resistive element. The resistive element can function as a stigmatization element. A conductive calibration line can also be printed on the document.[0018]
• Still another object of the invention is to provide a data card having a substrate, a number of data areas each covered by a release coat, circuit elements printed over the release coats on the data areas and a scratch-off coating applied to the circuit elements.[0019]
• A further object of the invention is to provide a laminated document having an information document and a circuit element located between the laminates. The document can include one or more of the circuit elements located between the information document and the laminates.[0020]
• These and other objects are accomplished by the present invention which is directed to a method for printing a document. In one embodiment of the invention, the method includes the steps of (1) selecting a marking medium that has a pre-determined machine-readable characteristic, and (2) selecting a document substrate that is compatible with the pre-determined machine-readable characteristic of the selected marking medium. An information symbol is secured to the selected document substrate. A security layer which includes the selected marking medium is also affixed to the document substrate so that the security layer is in at least partial register with the information symbol. The method can further include the step of affixing a blocking layer to the document substrate in at least partial register with the information symbol. The blocking layer can be affixed to the document substrate so that blocking layer is intermediate the information symbol and the security layer or so that the security layer is intermediate the information symbol and the blocking layer.[0021]
• In a second embodiment of the invention, the method includes the steps of (1) selecting a first marking medium that has a first pre-determined machine-readable characteristic; (2) selecting a second marking medium that has a second pre-determined machine-readable characteristic; and (3) selecting a document substrate which is compatible with both the first pre-determined machine-readable characteristic and the second pre-determined machine-readable characteristic. The document substrate is apportioned into at least a first portion and a second portion and a first information symbol is secured to the document substrate within the first portion. A first security layer that includes the first selected marking medium is also affixed to the first portion of the document substrate so that the first security layer is in at least partial register with the first information symbol. The method can also include the step of affixing a blocking layer to the document substrate in at least partial register with the first information symbol. The blocking layer can be affixed to the document substrate so that blocking layer is intermediate the first information symbol and the security layer or so that the security layer is intermediate the first information symbol and the blocking layer. The method can also include the step of affixing a second security layer that includes the second selected marking medium to the second portion of the document substrate so that the second security layer is in at least partial register with the second information symbol.[0022]
• A third embodiment of the invention is directed to a method for forming a lottery ticket. The method includes the steps of (1) selecting a first marking medium that has a first pre-determined machine-readable characteristic; (2) selecting a second marking medium that has a second predetermined machine-readable characteristic; and (3) selecting a ticket substrate which is compatible with both the first pre-determined machine-readable characteristic and the second pre-determined machine-readable characteristic. The ticket substrate is apportioned into at least a first portion and a second portion. A play symbol is printed over the ticket substrate within the first portion and a bar code is printed over the ticket substrate within the second portion. A first security layer that includes the first marking medium is affixed to the first portion of the ticket substrate, in at least partial register with the play symbol. The first security layer, which is removable by a player from the ticket substrate, is affixed to the ticket substrate so that the play symbol is intermediate the ticket substrate and the first security layer. The method can also include the step of securing a second security layer which includes the second selected marking medium to the second portion of the ticket substrate, in at least partial register with the bar code.[0023]
• Inks that can be printed with conventional printing methods, such as intaglio printing, screen printing, relief printing, planographic printing, letterpress printing, and flexographic printing, are especially useful as any of the selected marking media. The ink used is chosen for a particular machine-readable characteristic such as dry-state conductance, fluorescence, optical density, reflectance, and scattering. For example, an ink which has a known, measurable conductance in a dry-state can be used to print conductive layers on the document which serve as security layers.[0024]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a plan drawing of a probability lottery ticket having an electrical signature according to the invention;[0025]
• FIG. 2 is a plan drawing of the partial electrical circuit that provides the card in FIG. 1 its electrical signature;[0026]
• FIG. 3 is a schematic representation of a gravure printing press used to print the ticket in FIG. 1;[0027]
• FIG. 4 is a plan drawing of the first layer printed on the ticket in FIG. 1;[0028]
• FIG. 5 is a plan drawing of the second layer printed on the ticket in FIG. 1;[0029]
• FIG. 6 is a plan drawing of the third layer printed on the ticket in FIG. 1;[0030]
• FIG. 7 is a plan drawing of customized graphics printed on the first portion of the ticket in FIG. 1;[0031]
• FIG. 8 is a plan drawing showing the placement of the play indicia, validation number, inventory control number, and bar code which are printed on the ticket in FIG. 1;[0032]
• FIG. 9 is a plan drawing of the back of the ticket in FIG. 1;[0033]
• FIG. 10 is a plan drawing of the fourth layer printed on the ticket in FIG. 1;[0034]
• FIG. 11 is a plan drawing of the fifth and sixth layers printed on the ticket in FIG. 1;[0035]
• FIG. 12 is a plan drawing of the seventh layer printed on the lottery ticket on FIG. 1;[0036]
• FIG. 13 is a plan drawing of the eighth layer printed on the lottery ticket in FIG. 1;[0037]
• FIG. 14 is a perspective view of an electronic verification machine according to the invention;[0038]
• FIG. 15 is a perspective view of an alternative embodiment of an electronic verification machine according to the invention;[0039]
• FIG. 16 is a plan drawing of the user interface of the electronic verification machine in FIG. 14;[0040]
• FIG. 17 is a block diagram of the major internal components of the electronic verification machine in FIG. 14;[0041]
• FIG. 18 is a block diagram of the circuitry of the electronic verification machine in FIG. 14;[0042]
• FIG. 19 is a plan drawing of the partial printed circuit used to determine the authenticity and integrity of the bar code of the ticket in FIG. 1;[0043]
• FIG. 20 is a plan drawing of the partial printed circuit used to determine the authenticity and integrity of the play spot areas of the ticket in FIG. 1;[0044]
• FIG. 21 is a plan drawing of another printed partial circuit which can be used to determine the authenticity and integrity of a probability lottery ticket;[0045]
• FIG. 22 is a schematic circuit diagram of the completed circuit which is formed when the partial circuit in FIG. 20 is coupled to an electronic verification machine;[0046]
• FIG. 23 is a plan drawing of a probability lottery ticket before the ticket is printed with yet another partial circuit which be used to determine the authenticity and integrity of the ticket;[0047]
• FIG. 24 is a plan drawing of the release coat printed on the ticket in FIG. 23;[0048]
• FIG. 25 is a plan drawing of the partial circuit used to determine the authenticity and integrity of the ticket in FIG. 23;[0049]
• FIG. 26 is a plan drawing of the ticket in FIG. 23 in its final printed format;[0050]
• FIG. 27 is a plan drawing of a second embodiment of the release coat printed on the ticket in FIG. 23;[0051]
• FIG. 28 is a plan drawing of the circuit used to determine the authenticity and integrity of the ticket in FIG. 23;[0052]
• FIG. 29 is a plan drawing of another circuit which can be used to determine the authenticity and integrity of a probability game ticket;[0053]
• FIG. 30 is a plan drawing of another circuit which can be used to determine the authenticity and integrity of a probability game ticket;[0054]
• FIG. 31 is a plan drawing of four printed resistors having different resistances;[0055]
• FIG. 32 is a plan drawing of a partial printed circuit which includes a calibration line;[0056]
• FIG. 33 is a partial plan drawing illustrating a ticket inductively coupled to an electronic verification machine;[0057]
• FIG. 34 is a partial plan drawing of a conductor which can be printed on a ticket to provide an RF antenna;[0058]
• FIG. 35 is a partial schematic circuit diagram of circuit which measures thermal variations to determine the authenticity and integrity of a ticket;[0059]
• FIG. 36 is a plan drawing of a lottery ticket having sixteen play spot areas;[0060]
• FIG. 37 is a plan drawing of the ticket in FIG. 36 having the play spot areas removed to reveal the underlying play indicia;[0061]
• FIG. 38 is a block diagram of a second embodiment of an electronic verification machine;[0062]
• FIG. 39 is a partial sectioned side view of the electronic verification machine of FIG. 38 illustrating a document transport mechanism;[0063]
• FIG. 40 is a block diagram of a portion of the circuitry of the electronic verification machine of FIG. 38;[0064]
• FIG. 41 is a schematic diagram of a position sensor array and buffer circuit that can be used with the circuit of FIG. 39;[0065]
• FIG. 42 is a perspective view of an alternative position sensor array that can be used with the electronic verification machine of FIG. 38;[0066]
• FIG. 43 is a plan view of a first lottery ticket suitable for use with the electronic verification machine of FIG. 38;[0067]
• FIG. 44 is a game signature map representing the location of a scratch-off coating having conductive material on the lottery ticket of FIG. 43;[0068]
• FIG. 45 is a data map representing the data out put of the electronic verification machine of FIG. 38 for the lottery ticket of FIG. 43;[0069]
• FIG. 46 is an exploded perspective view of a pull-tab lottery ticket;[0070]
• FIG. 47 is an illustrative top view of the pull-tab lottery ticket of FIG. 46 in conjunction with a signature map;[0071]
• FIG. 48 is an illustrative top view of the pull-tab lottery ticket of FIG. 46 positioned below an electronic verification machine sensor array;[0072]
• FIG. 49 is a plan drawing of a second embodiment of a probability ticket according to the invention;[0073]
• FIG. 50 is a plan drawing of the circuit elements that form parts of the ticket shown in FIG. 49;[0074]
• FIG. 51 is a schematic representation of a gravure printing press used to print the ticket in FIG. 49;[0075]
• FIG. 52 is a plan drawing of a first blocking layer that is part of the ticket in FIG. 49;[0076]
• FIG. 53 is a plan drawing of an alternative embodiment of the first blocking layer shown in FIG. 53;[0077]
• FIG. 54 is a plan drawing of a second alternative embodiment of the first blocking layer shown in FIG. 53;[0078]
• FIG. 55 is a plan drawing of one of the circuit elements in FIG. 49 as printed on the first blocking layer in FIG. 52;[0079]
• FIG. 56 is a plan drawing of one of the circuit elements in FIG. 49 as printed on the first blocking layer in FIG. 53;[0080]
• FIG. 57 is a plan drawing of one of the circuit elements in FIG. 49 as printed on the first blocking layer in FIG. 54;[0081]
• FIG. 58 is a plan drawing of a masking layer that is apart of the ticket shown in FIG. 49;[0082]
• FIG. 59 is a plan drawing of a primer layer that is apart of the ticket shown in FIG. 49;[0083]
• FIG. 60 is a plan drawing of the display portion graphics that are part of the ticket shown in FIG. 49;[0084]
• FIG. 61 is a plan drawing of play indicia which are part of the ticket shown in FIG. 49;[0085]
• FIG. 62 is a plan drawing of the back of the ticket shown in FIG. 49;[0086]
• FIG. 63 is a plan drawing of a seal coat which is part of the ticket shown in FIG. 49;[0087]
• FIG. 64 is a plan drawing of a release coat which is part of the ticket shown in FIG. 49;[0088]
• FIG. 65 is a plan drawing of an upper blocking layer that is part of the ticket shown in FIG. 49;[0089]
• FIG. 66 is a plan drawing of an alternative embodiment of the upper blocking layer in FIG. 65;[0090]
• FIG. 67 is a plan drawing a second alternative embodiment of the upper blocking layer in FIG. 65;[0091]
• FIG. 68 is a plan drawing of some of the circuit elements shown in FIG. 50 as printed on the blocking layer shown in FIG. 65;[0092]
• FIG. 69 is a plan drawing of some of the circuit elements shown in FIG. 50 as printed on the blocking layer shown in FIG. 66;[0093]
• FIG. 70 is a plan drawing of some of the circuit elements shown in FIG. 50 as printed on the blocking layer shown in FIG. 67;[0094]
• FIG. 71 is a plan drawing is a plan drawing of a scratch-off layer that is part of the ticket shown in FIG. 49;[0095]
• FIG. 72 is a plan drawing of a combined seal-release coat that can be used on the ticket instead of the seal coat and the release coat that are shown in FIGS. 63 and 64, respectively;[0096]
• FIG. 73 is an enlarged plan drawing of one of the circuit elements shown in FIG. 50 and illustrates a first printing defect;[0097]
• FIG. 74 is a plan drawing of the circuit element in FIG. 72 and illustrates a second printing defect;[0098]
• FIG. 75 is an enlarged plan drawing of one of the circuit elements in FIG. 50 and shows the configuration of the circuit element relative to a play indicia and a release coat portion or a seal-release coat portio;[0099]
• FIG. 76 is a plan drawing of an alternative embodiment of the circuit element shown in FIG. 75;[0100]
• FIG. 77 is a plan drawing of a marker card according to the invention;[0101]
• FIG. 78 is a plan drawing of the circuit elements which are part of the marker card shown in FIG. 77;[0102]
• FIG. 79 is a plan drawing is a plan drawing of the play indicia which are part of the marker card in FIG. 77;[0103]
• FIG. 80 is a plan drawing of a seal coat which is part of the marker card in FIG. 77;[0104]
• FIG. 81 is a plan drawing of a release coat that is part of the marker card in FIG. 77;[0105]
• FIG. 82 is a plan drawing of an alternative embodiment of the release coat shown in FIG. 81;[0106]
• FIG. 83 is a plan drawing seal-release coat that can be used instead of the seal coat and the release coat that are shown in FIGS. 80 and 81, respectively;[0107]
• FIG. 84 is a plan drawing of an alternative embodiment of the seal-release coat in FIG. 83;[0108]
• FIG. 85 is a plan drawing of the circuit elements in FIG. 78 as printed on the release coat shown in FIG. 81;[0109]
• FIG. 86 is a plan drawing of the circuit elements in FIG. 78 as printed on the release coat shown in FIG. 82;[0110]
• FIG. 87 is a plan drawing of the circuit elements in FIG. 78 as printed on the seal-release coat shown in FIG. 83;[0111]
• FIG. 88 is a plan drawing of the circuit elements in FIG. 78 as printed on the seal-release coat shown in FIG. 84;[0112]
• FIG. 89 is a plan drawing of a scratch-off layer that is part of the ticket shown in FIG. 77;[0113]
• FIG. 90 is a plan drawing of a data card according to the invention;[0114]
• FIG. 91 is a plan drawing of an alternative embodiment of the data card in FIG. 91;[0115]
• FIG. 92 is a plan drawing a laminated document according to the invention;[0116]
• FIG. 93 is a plan drawing of a lower laminate and a lower circuit element that is part of the laminated document in FIG. 92;[0117]
• FIG. 94 is a plan drawing of an upper laminate and an upper circuit element that is part of the laminated document in FIG. 92;[0118]
• FIG. 95 is a plan drawing of an information document that is part of the laminated document shown in FIG. 92;[0119]
• FIG. 96 is a perspective view of a third electronic verification machine according to the invention;[0120]
• FIG. 97 is a side perspective view of the electronic verification machine in FIG. 96 with the cover removed;[0121]
• FIG. 98 is a partially cut-away exploded side perspective view of the electronic verification machine in FIG. 96;[0122]
• FIG. 99 is a block diagram of the relationship among the major components of the electronic verification machine in FIG. 96;[0123]
• FIG. 100 is a top plan view of a sensor head which forms a part of the electronic verification machine in FIG. 96;[0124]
• FIG. 101 is a simplified partial circuit diagram of the capacitive coupling between the sensor head in FIG. 100 and a document being tested;[0125]
• FIG. 102A is a plan view of a first printed layer pattern that can be used with the electronic verification machine in FIG. 96;[0126]
• FIG. 102B is a conceptual representation of two capacitors which are formed when the sensor array of the electronic verification machine in FIG. 96 is capacitively coupled to a document which contains the first printed layer pattern shown in FIG. 102A;[0127]
• FIG. 103A is a plan view of a second printed layer pattern that can be used with the electronic verification machine in FIG. 96;[0128]
• FIG. 103B is a conceptual representation of two capacitors which are formed when the sensor array of the electronic verification machine in FIG. 96 is capacitively coupled to a document which contains the second printed layer pattern shown in FIG. 103A;[0129]
• FIG. 104A is a plan view of a third printed layer pattern that can be used with the electronic verification machine in FIG. 96;[0130]
• FIG. 104B is a conceptual representation of two capacitors which are formed when the sensor array of the electronic verification machine in FIG. 96 is capacitively coupled to a document which contains the third printed layer pattern shown in FIG. 104A;[0131]
• FIG. 105 is a example of a printed circuit element that can be electronically altered by the electronic verification machine in FIG. 96, to stigmatize a document being tested;[0132]
• FIG. 106 is a functional block diagram of a stigmatization circuit that can be used to stigmatize a document having the printed circuit element of the type shown FIG. 105; and[0133]
• FIG. 107 is a conceptual diagram which illustrates the use of the electronic verification machine in FIG. 96 to measure the thickness of a document being tested.[0134]
DETAILED DESCRIPTION OF THE INVENTION
• I. General Overview[0135]
• The present invention is directed to a method and to an interrelated group of devices for determining the authenticity and integrity of a document and includes printing a portion of an electrical circuit on the document or applying a material having electrical conductive properties on the document. “Document”, as that term is used herein, is not limited to conventional printed papers but includes any type of flexible substrate as well as rigid substrates such as printed circuit boards. A document is authentic if it is not the product of counterfeiting. The integrity of a document relates to its current physical state as compared to its initial physical state and is affected by unauthorized modifications or attempted modifications of the document by, for example, subjecting the document to chemicals, heat, light, or pressure. The electrical characteristics of the printed circuit or the location of the conductive material provide the basis for determining both the authenticity and the integrity of the document. These characteristics can also be used to obtain data from the document.[0136]
• A first method is to choose a predetermined, measurable electrical property, for example, a known resistance or capacitance, that will serve as the electrical signature of the document. Next, at least a portion of an electrical circuit is printed on the document using conductive or semi-conductive inks. The electrical circuit is designed so that when the circuit is completed, the circuit will generate an electrical signature that is substantially equal to a chosen predetermined electrical signature. Last, the circuit on the document is coupled to an electronic verification machine for determining the authenticity and integrity of the document by comparing the signal characteristics of the circuit on the document to the predetermined signature.[0137]
• The electronic verification machine provides at least three functions. First, the electronic verification machine completes the circuit and provides a power source for exciting the circuit. Second, the electronic verification machine measures the resulting electrical signature of the document. And third, the electronic verification machine determines whether the measured electrical signature is substantially the same as the predetermined electrical signature. There are a number of ways in which the electronic verification machine can determine the authenticity and integrity of the document. The electronic verification machine can directly determine the authenticity and integrity of the document by using data directly available to the electronic verification machine. Alternatively, the electronic verification machine can indirectly determine the authenticity and integrity of a document by communicating the measured electrical signature to a remote computer which contains data related to the predetermined electrical signature for the document.[0138]
• Determining the authenticity and integrity of the document is, in its simplest form, a logical progression. Generally, if an electrical signature can not be measured, the document is not authentic, is not in its original integral state, or both. On the other hand, if an electrical signature can be measured and the measured electrical signature is substantially the same as the predetermined electrical signature, the document can be assumed to be authentic and in its original integral state. If an electrical signature can be measured but is substantially different than the predetermined electrical signature, at the very least the document is not in its original integral state. This method will be explained in terms of a representative document which in this case is a probability game lottery ticket.[0139]
• A second method is similar to the first method but involves the determination of the location of conductive materials on the document. This method will be explained in conjunction with the second embodiment of the electronic verification machine.[0140]
• II. Probability Game Lottery Ticket Configuration.[0141]
• The preferred embodiment of the invention is an electronic verification machine that can be used to determine the integrity and authenticity of a document, such as a probability game lottery ticket. Consequently, a brief overview of probability game lottery tickets is helpful. A probability game lottery ticket typically includes a group of play areas or play spots, each containing play indicia covered by an opaque material, usually a latex material. A player can win a prize if he removes the latex from a predetermined combination or combinations of play spots which define one or more winning redemption values. Generally the player is instructed to rub off only a specified number of play spots. Thus, a game may require a player to rub off three play spots. In this case, if the player rubs off more than three play spots, the ticket is void and player automatically loses. If the play indicia under the removed play spots match one of the predetermined combination(s), the player is eligible to redeem the ticket for a prize. On the other hand if the removed play spots do not match one of the predetermined combination(s), the redemption value of the ticket will be zero.[0142]
• FIG. 1 illustrates the final printed format of a[0143]probability game ticket50 according to one embodiment of the invention. Theticket50 includes acard substrate52 which is generally divided into two portions. Afirst portion54, the display portion, contains various types of printed information such as thename56 of the probability game,information58 related to the rules for playing the ticket, and customizedart work60. A second portion, theplaying field portion62, includesoverprint areas66,68 and76. Thesquare overprint areas66 define a group of play spot areas72A-H of theticket50. As shown in FIG. 1, the overprint area of one play spot area72A has been rubbed off the reveal theunderlying play indicia74. The play indicia74 can take any on a variety of forms including, as shown here, a dollar value. The play indicia74 can also be formed from letters or words alone, numbers alone, or symbols alone, or any combination of letters, numbers, or symbols. Although not illustrated, it is to be understood that play indicia similar to playindicia74 underlie each of theplay spot areas72B-H.
• The[0144]overprint area76 defines the void-if-removed area of theticket50. Avalidation number78, shown in FIG. 8, underlies the void-if-removed area defined by theoverprint area76. Thevalidation number78 contains various types of security information including a portion that is usually algorithmically related to the pack number and ticket number for a particular ticket, such as theticket50. The pack number identifies the pack from which theticket50 originates. The ticket number relates to the position of theticket50 within the pack. In addition as will be explained below, thevalidation number78 can also include information related to the electrical signature(s) of theticket50. Thevalidation number78 is useful for determining the authenticity and integrity of theticket50, as explained in greater detail below, in Section V.
• A[0145]bar code80 is also printed within theplaying field portion62 of theticket50. Thebar code80 can include information related to the validation number, the pack and ticket numbers for theticket50 and to the redemption values of various combinations of the play indicia74 in each of the play spot areas72A-H. Thebar code80 can also be used to store information about the value of the play indicia74 on theticket50, as is explained in greater detail below, in Section V.
• FIG. 2. illustrates a partial[0146]electrical circuit81 which is interposed between the overprint areas64-68 and the play indicia74 of theticket50 shown in FIG. 1. In the preferred embodiment, thecircuit81 includes eight resistor tracks82-96 which are divided into two columns of four resistor tracks each. Each resistor track82-96 underlies theoverprint areas68 shown in FIG. 1 which define each of the play spot areas72A-H in FIG. 1. In addition, each resistor track82-96 overlies a play indicia such as74. Eight conductive or capacitive pick-upareas98A-H are located around the periphery of the resistor tracks82-96 and a centralconductive track100 is located between the two columns of resistor tracks82-96. The centralconductive track100 is connected to a conductive I-track shown at102 which includes a terminalconductive bar104 and a secondconductive bar106 parallel to and spaced apart from the terminalconductive bar104. Aresistive track107 connects the terminalconductive bar104 to the secondconductive bar106. In the final printed format, such as that shown in FIG. 1, the terminalconductive bar104 underlies thebar code80.
• Each resistor track[0147]82-96 is electrically connected to the centralconductive track100 and to one of theconductive areas98A-H, for example,resistor track82 is electrically connected to centralconductive track100 and toconductive area98A. Theconductive areas98A-H and the centralconductive track100 are used to capacitively couple theticket50 to anelectronic verification machine108, such as that illustrated in FIG. 14. In the preferred embodiment, eachconductive area98A-H acts as a capacitor plate, the other capacitor plate being provided by theelectronic verification machine108. In addition, the centralconductive track100 also acts as a capacitor plate, the second capacitor plate being provided by theelectronic verification machine108. The capacitive coupling of theconductive areas98A-H and the centralconductive track100 to theelectronic verification machine108 completes the printedcircuit81 and permits theelectronic verification machine108 to excite the circuit and to measure the electrical signature or signatures ofticket50. Since the capacitive coupling of theconductive areas98A-H and the centralconductive track100 to theelectronic verification machine108 permits theelectronic verification machine108 to measure the electrical signature(s) ofticket50,areas98A-H and track100 are also known as capacitive pick-up areas because through these areas theelectronic verification machine108 “picks-up” the electrical signature ofticket50.
• Because each of the resistor tracks[0148]82-96 is electrically connected to both the centralconductive bar100 and to one of theconductive areas98A-H, each of the resistor tracks82-96 forms a complete circuit when theticket50 is coupled to theelectronic verification device108. Thus each of the resistor tracks82-96 has its own electrical signature equal to the printed resistance of the resistor track. As shown in FIG. 2, each of the four resistor tracks in the two columns has the same resistance. Since each of the resistor tracks82-96 is electrically connected to its associatedconductive area98A-H, the integrity of the eight circuits containing the eight resistor tracks82-96 can be determined by reference to the specificconductive area98A-H used to measure the electrical signature. Alternatively, each resistive track may have a unique resistance. For example, theresistor track82 can have a resistance of 100 KΩ, theresistor track84 can have a resistance of 300 KΩ, theresistor track86 can have a resistance of 500 KΩ, and theresistor track88 can have a resistance of 2700 KΩ. Similarly, the resistor tracks90-96 can have resistances of 100 KΩ, 300 KΩ, 500 KΩ, and 700 KΩ respectively. As is explained in greater detail in Sections III and IV.C.1., the magnitude of the resistance for a specific resistor track is a function of the type of ink used to print the resistor track, the length of the resistor track and the cross-sectional area, including the thickness, of the resistor track. Differences in the four resistances82-88 or90-96 in a given column of resistor tracks facilitate the determination of the authenticity and the integrity of theticket50 and more particularly can be used to determine which of theoverprint areas68 have been rubbed off.
• [0149]Circuit81, as shown in FIG. 2, is actually a composite of several layers used to printticket50. The following section describes in detail the sequence and relationship of the various layers used to printticket50.
• III. Printing The Electrical Signature[0150]
• In the preferred embodiment, the[0151]circuit81 is printed onto theticket50 preferable via a gravure printing process. The gravure printing process allows for the widest range of ink and coating formulations. The gravure printing process, however, is not the only printing process that can be used to print the circuits. Gravure is only one type of intaglio printing process. Other types of intaglio printing processes can be used as well. In addition, thecircuit81 can be printed via screen printing, relief printing, planographic printing, letterpress and flexographic printing. In the preferred embodiment, theticket50 is printed on a paper substrate. Paper substrates are preferred because they offer good insulation and absorbency. Alternatively, theticket50 could be printed on a plastic or a metal, such as an aluminum foil, substrate. If a foil substrate is used, portions of the foil can serve as the main conductor for theticket50, while other portions of theticket50 are covered with an insulating layer.
• FIG. 3 is a schematic diagram representing a[0152]gravure printing press112 suitable for printingticket50. Thepress112 has fifteen gravure printing stations114-142 and oneink jet station144. As is explained in more detail below, each of the press stations114-142 prints one layer on theticket50 while theink jet printer144 prints theplay indicia74 and thebar code80.
• [0153]Station114 prints a first layer orsurface146 which is shown in FIG. 4. Thefirst layer146 is printed with a conductive-carbon based ink and forms a part of thecircuit81 shown in FIG. 2. Thefirst layer146 includes two portions the first of which is an I-track148. The I-track148 includes the terminalconductive bar104 and theresistive track107 which form part of the I-track102 illustrated in FIG. 2. A secondconductive bar150 of the I-track148 underlies the secondconductive bar106 of the I-track102 of FIG. 2. The second portion of thefirst layer146 consists of a pair of rows of blockingcells152. Each of the blockingcells152 is positioned to underlie one of the play indicia74 which are subsequently printed on theticket50.
• The ink used to print the[0154]layer146 should have a sheet resistivity below 2,700 Ω/□ preferably in the range of 1,000 Ω/□ to 1,300 Ω/□. In theticket50 shown in FIGS.1-13, the ink used to print the lowerconductive layer146 would most desirably have a sheet resistivity of 1,200 Ω/□. “Sheet resistivity” (ρs), as that term is used herein, is the bulk resistivity of the ink (ρ) divided by the thickness of the film of ink (t) printed on theticket50.
• ρs=ρ/t.
• Sheet resistivity (ρs) will typically be expressed in terms of ohms/square (Ω/□) . In practice, the sheet resistivity of an ink is determined by printing and measuring the resistance of a unit length and width.[0155]
• The resistance (R) of a specific resistor in turn is a function of the bulk resistivity of the material and the dimensions of the resistor:[0156]
• R=ρ(l/tw)
• where ρ is the bulk resistivity of the material used to make the resistor, l is the length of the resistor, t is the thickness of the resistor and w is the width of the resistor. Substituting the previous equation for sheet resistivity into the equation for resistance yields the following:[0157]
• R=ρs(l/w)
• Thus, the resistance of a resistor printed with a conducting or semi-conducting ink is a function of the sheet resistivity of the ink, the length of the printed resistor, and the width of the printed resistor. For example, the resistance of a printed resistor with an ink having ρs=100 Ω/□ which is 0.120 inches (0.3048 cm) long and 0.040 inches (0.1016 cm) wide would be:[0158]
• R=ρs(l/w)=100 Ω/□(0.0120/0.040)=300 Ω.
• The ink used to print the[0159]first layer146 should also have very good adhesive properties so that thelayer146 adheres well to theticket50 and should have good abrasion resistance properties so that thelayer146 is not easily rubbed off theticket50. A preferred formulation for the ink used to print thefirst layer146 is given in Table 1.

  TABLE 1
  Preferred Ink Formulation ForLayer 1

  	material	wt %
  	Acrylic Resin	12-18%
  	Pentaerythritol ester of	2-6%
  	modified rosin
  	Conductive carbon	14-20%
  	Polyamine amide/acidic	0.3-1.0%
  	ester dispersant
  	2-ethyhexyl diphenyl phosphate	2-5%
  	plasticizer
  	Anhydrous ethyl alcohol	20-30%
  	Normal Propyl acetate	23-33%
  	50/50 mixed solvent, normal	5%
  	propyl acetate andethyl
  	alcohol
  	950varnish	5%

• The 950 varnish comprises 36.24% normal propyl acetate, 24.92% DM55 acrylic, 12.92[0160]% pentalyn830, 17.92% nitro varnish, and 3% santicizer141. The preferred formulation provides a film former, solvent based ink. Film formers are polymers capable of being plasticized to form a continuous and totally flexible ink. In the preferred formulation, the solvent evaporates from the printed surface during drying leaving a continuous, conductive dry ink film. Preferably, the conductive carbon will be about 2-20μ in size in this formulation.
• The[0161]first layer146 serves at least two purposes. First, the solid black nature of the blockingcells152 of thefirst layer146 serves to prevent unauthorized detection of theplay indicia74, for example, by shining a bright light through theticket50. Second, the I-track148 can be used to protect thebar code80 against unauthorized modifications, by providing an electrical signature for thebar code80 which can be measured by theelectronic verification machine108. It should be noted that in some cases, especially where theticket50 does not include the blockingcells152, it may be desirable to print an opaque blocking layer between thesubstrate52 and theplay indicia74.
• [0162]Station116 prints thesecond layer156 which is shown in FIG. 5. Thesecond layer156 has two portions: anupper portion156aand alower portion156b. Theupper portion156aoverlies all of the blockingcells152 of thefirst layer146 shown in FIG. 4. Thelower portion156boverlies the terminalconductive bar104 and theresistive track107 of the I-track148 of thefirst layer146. The gap between theupper portion156aand thelower portion156bexposes the secondconductive bar150 of the I-track148 of thefirst layer146. Thesecond layer156 acts as a blocking layer to prevent thefirst layer146 from obscuring observation of theplay indicia74 when theticket50 is played. A suitable formulation for thesecond blocking layer156 is disclosed in U.S. patent application Ser. No. 08/004,157 the entire disclosure of which is hereby incorporated by reference.
• A[0163]third layer158 is then printed by theprinting station118. The placement of thethird layer158 is essentially coincident with thesecond layer156, as shown in FIG. 6. Thethird layer158 also includes aupper portion158aand alower portion158bseparated by a gap which exposes the secondconductive bar150 of the I-track148. Thethird layer158 is a primer layer which provides a suitable surface for printing theplay indicia74. A suitable formulation for the third primer layer is disclosed in Walton, U.S. Pat. No. 4,726,608.
• Printing stations[0164]120-126 provide the features printed on thedisplay portion54 of theticket50, as shown in FIG. 7. These printed features include thename56 of the probability lottery game,information58 related to the rules for playing the game, and customizedart work60. Because 4 different printing stations120-126 are used to print these features, as many as four different colors of ink can be used to print process colors.
• The[0165]ink jet printer144 prints the play indicia74 on a portion of thethird layer158, as shown in FIG. 8. In the preferred embodiment, there are two columns ofplay indicia74, each of which contains fourseparate play indicia74. The two rows ofplay indicia74 are positioned so that eachseparate play indicia74 overlies one of the blockingcells152 of thefirst layer146 shown in FIG. 4. Theink jet printer144 also prints theinventory control number70, thevalidation number78, and thebar code80 on theticket50. In the preferred embodiment, theinventory control number70, theplay indicia74, thevalidation number78, and thebar code80 are printed with a water-based dye.
• [0166]Printing station128 prints the back157 of theticket50 as shown in FIG. 9. The back157 may includeadditional information159 related to the rules for playing theticket50.
• The[0167]print station130 prints afourth layer160 on theticket50. Thefourth layer160 is indicated by the shaded portions in FIG. 10. The fourth layer covers the upper andlower portions158a,158bof thethird layer158 shown in FIG. 7, and also covers theplay indicia74, theinventory control number70, thevalidation number78, and thebar code80. In the same manner as the second andthird layers156 and158, the fourth layer does not cover the secondconductive bar150 of the I-track148. Thefourth layer160 is a seal coat which protects theinventory control number70, playindicia74, thevalidation number78, and thebar code80 from abrasion and from liquids in which theplay indicia74, thevalidation number78, and thebar code80 are soluble. Suitable materials for this purpose include various polymer materials such as acrylics, polyester urethane, epoxy acrylate, and vinyl polymer. A suitable formulation for thethird primer layer158 of FIG. 6 is disclosed in Walton, U.S. Pat. No. 4,726,608.
• The[0168]print stations132 and134 print a fifth and asixth layer162 on theticket50. As shown in FIG. 11, the fifth andsixth layers162 are printed as discrete sections which overlie theplay indicia74 and thevalidation number78. The fifth andsixth layers162 are indicated by the shaded areas overlying theplay indicia74 and thevalidation number78. The fifth andsixth layers162 are both substantially transparent release coats which allow the play indica74 to be viewed by the player and at the same time permit an easy removal of subsequent layers by, for example, rubbing theticket50 with a fingernail. The same release coat formula on may be used to print both the fifth andsixth layers162. A suitable formulation for the third layer is disclosed in Walton, U.S. Pat. No. 4,726,608. Also, in some cases it may be desirable to use an ultraviolet curable seal-release coat in place of the release coats162. Such seal-release coats are well known in the art.
• The[0169]print station136 prints aseventh layer164 which comprises the remainder of theelectrical circuit81 shown in FIG. 2 which is printed on theticket50. As illustrated in FIG. 12, theseventh layer164 is a patterned layer which includes the resistor tracks82-96 and theconductive areas98A-H. Theseventh layer164 also includes theconductive bar106 of the I-track102 shown in FIG. 2. As explained earlier, the resistor tracks82-96 are connected to theconductive areas98A-H. The resistor tracks82-96, as printed thus have electrical continuity with theconductive areas98A-H andconductive track100.
• The relationship between the[0170]first layer146 and theseventh layer164 is better understood with reference to FIGS. 19 and 20 which are respectively plan drawings of thefirst layer146 and of theseventh layer164 alone. As noted earlier, thefirst layer146, shown by itself in FIG. 19, consists of the blockingcells152 and the I-track148. The I-track148 includes the terminalconductive bar104 and theresistive bar107. Theseventh layer164, shown by itself in FIG. 20, consists of the resistive tracks82-96, theconductive areas98A-H, the centralconductive track100 and theconductive bar106. Theseventh layer164 is positioned on theticket50 so that theconductive bar106 of the seventh layer overlies theconductive bar150 of thefirst layer146 to form thepartial circuit81 as illustrated in FIG. 2. The overlying relationship ofconductive bars106 and150 ensures electrical continuity between thefirst layer146 and theseventh layer164.
• It is desirable that the ink used to print the[0171]seventh layer164 have a sheet resistivity at least in the range of 300 Ω/□ to 600 Ω/□ and preferably, the sheet resistivity should be below 300 Ω/□. Several parameters can be varied to reduce the sheet resistivity of an ink. For example, the shape and size of the conductive particles affects the sheet resistivity of the ink. In addition, metal pigments tend to reduce the sheet resistivity as does a high pigment to binder ratio. However, both metal pigment and a high pigment to binder ratio tend to reduce the graphic adhesiveness of the ink. Unlike the ink used to print thefirst layer146, the ink used to print theseventh layer164 need not have exceptional adhesive properties because theseventh layer164 or portions thereof are designed to be removed to reveal theplay indicia74 when theticket50 is played. Consequently, the ink used to print theseventh layer164 on theticket50, or circuits on other types of documents where the adhesive qualities of the ink are not a major consideration, can include metal particles and can have a relatively high pigment to binder ratio. The use of metal particles in place of or in addition to carbon particles can substantiality increase the conductivity of the ink.
• A preferred ink formulation for the[0172]seventh layer164 is given in Table 2.

  TABLE 2
  Preferred Conductive Ink Formulation For
  Layer 7

  	material	wt %
  	Acrylic resin	10-15%
  	Pentaerythritol ester of	1-5%
  	modified rosin
  	conductive carbon	5-15%
  	silver plated copper	10-25%
  	particles (5-10μ)
  	polyamine amide/acid	0.25-0.75%
  	ester dispersant
  	anhydrous ethyl alcohol	25-35%
  	normal propyl acetate	28-38%

• Although the preferred metal particles are sliver plated copper particles, other conductive metal particles such as aluminum, brass, nickel, iron and iron oxide particles can be used as well. However, it should be noted that nickel may not be suitable for use in certain types of documents since it can be toxic if ingested. Also, in addition to sliver, the metal particles can be plated with gold or tin.[0173]
• An[0174]eighth layer168, preferably a scratch-off latex material, is applied atprinting station138. As shown in FIG. 13, theeighth layer168 covers most of theplaying field portion62 of theticket50. Theeighth layer168 does not cover theinventory control number70 or thebar code80. The eightlayer168 does, however, overlie theconductive bar102 of theseventh layer164. Thefinal printing stations138,140, and142 apply overprint graphics such asoverprint areas66,68, and76 illustrated in FIG. 1. Thesquare overprint areas68 serve to visually identify the individual play spot areas72A-H and theoverprint area76, which overlies thevalidation number78, is printed with the instruction “void if removed.”
• IV. Measuring The Printed Electrical Signature[0175]
• A. An Electronic verification Machine[0176]
• As stated earlier, the[0177]circuit81 on theticket50 is completed when theticket50 is capacitively coupled to the electronic validation orverification machine108 which then can measure the electrical signature of the circuit elements such as resistors82-96 on theticket50. FIG. 14 is a stylized perspective view of an exterior of theelectronic verification machine108. Although the exact configuration of the exterior of theelectronic verification machine108 can vary, the exterior of theelectronic verification machine108 has three features: aresults indicator174, aticket interface176, and auser interface178. As shown in FIG. 14, theresults indicator174 of theelectronic verification machine108 is adisplay panel180. Thedisplay panel180 can display the results of a ticket validation operation and can also display the results of verification testing, including tests of the authenticity and integrity of theticket50. Thedisplay panel180 can also display instructions, such as “Insert Ticket”, concerning the use of theelectronic verification machine108. In place of or in combination with thedisplay panel180, theelectronic verification machine108 can communicate with aprinter181 shown in FIG. 17 which can display the results of the ticket validation operation and verification testing as well. Theuser interface178 can be a keyboard which the player or an agent can use to manually enter data from the ticket into the electronic verification machine.
• A[0178]ticket interface176 of theelectronic verification machine108 includes aticket slot182 into which theticket50 can be inserted. When theticket50 is properly inserted into theticket slot182, theconductive areas98A-H,100, and106 are aligned with an array ofcapacitor plates226A-H,228 and230, as shown in FIG. 18, located within theelectronic verification machine108, to complete thepartial circuit81 printed on theticket50. In addition, thebar code80 is aligned with a bar code reader210 (not shown) located within theelectronic verification machine108.
• FIG. 15 is a stylized plan drawing of an alternative embodiment of an[0179]electronic verification machine183 having a different type ofticket interface177. In this embodiment theelectronic verification machine183 has a hinged lid184 which can be raised to expose theticket interface177 which includes aticket recess186. Within theticket recess186 is asensor area188 containing an array of capacitor plates (not shown) which align with thecapacitor areas98A-H,100, and106 on theticket50. Theticket recess186 also includes a barcode reader area190. Theticket50 is placed within theticket recess186 such that thebar code80 can be read throughreader area190 by abar code reader210 located within theelectronic verification machine183 as illustrated in FIG. 17. Theelectronic verification machine183 can also have asecond sensor area192 also containing capacitor plates (not shown) which align with theconductive areas98A-H,100, and106 onticket50.
• FIG. 16 is a plan view of the preferred embodiment of the[0180]user interface keyboard178. Theuser interface178 includes a numerickey pad196 and a set of operation keys198-204. Theoperation key200 is used to input thevalidation number78 of theticket50 into theelectronic verification machine108 and theoperation key198 is used to manually input thebar code80 of theticket50 into theelectronic verification machine108. Keying in of thebar code80 may be necessary if thebar code reader210 is not able to read the bar code because, for example, thebar code80 is damaged or perhaps has been tampered with.
• FIG. 17 is a sectioned side view which includes a block diagram of the major internal components of the[0181]electronic verification machine108. The electronic verification machine includes thebar code reader210, and aticket sensor212. Theticket sensor212 senses when theticket50 has been properly inserted so that thebar code80 can be read by thebar code reader210. When the ticket is properly inserted theconductive areas98A-H,100, and106 of theticket50 are aligned with a pair of sensor plates, indicated at214 and216, which include an array ofcopper capacitor plates226A-H,228 and230, shown in FIG. 18, positioned in a configuration which mirrors that of the conductive orcapacitor areas98A-H,100, and106 of theticket50. Thesensor plates214,216 are part of asensor head218 which contains a set of excitation and detection circuitry for theelectronic verification machine108. Theelectronic verification machine108 also includes aprocessor board220, including a microprocessor and memory, and acommunications interface222.
• The excitation and detection circuitry of the[0182]sensor head218 includes amicrocontroller224 with associated memory as shown in FIG. 18. Themicrocontroller224 provides the necessary logic to control theelectronic verification machine108 and performs various tasks including controlling thecommunications interface222, theuser interface178, and thebar code reader210. Themicrocontroller224 also processes the measured electrical signature of the circuit elements82-96 on theticket50 that can be used to determine the authenticity and integrity of theticket50. Because themicrocontroller224 requires relatively little processing power, a single, self-contained IC can be used to provide inexpensive processing. Examples of acceptable chips include the Motorola 68HC711E9 and the Intel MCS®-51 Series microcontrollers. Each of these chips includes a Random Access Memory (“RAM”) and a Programmable Read Only Memory (“PROM”) and an Analog to Digital converter (“A/D”).
• As is explained in greater detail below, in Section V., the[0183]bar code80 can include information regarding the value of the play indicia74 of theticket50. Thebar code reader210 communicates directly with themicrocontroller224 via an ANSI standard interface, for example, UART. In the preferred embodiment, thebar code reader210 is a laser scanner.
• The[0184]communications interface222 generally is a serial digital interface which may be a driver IC or a modem chip set. As is explained in more detail in Section V. below, the serialdigital interface222 allows theelectronic verification machine108 to communicate with acentral host computer223 when necessary to determine the authenticity or integrity of theticket50. In the preferred embodiment, a non-standard interface or a low-level encryption is included in the design of the serialdigital interface222 in order to enhance the security of communications between theelectronic verification machine108 and thecentral computer223.
• In operation, the excitation and detection circuitry of the[0185]sensor head218 is capacitively coupled with thepartial circuit81 printed on theticket50 to complete thecircuit81. Thus, a complete circuit225 including thepartial circuit81 on theticket50, as shown in FIG. 21, is completed81 when theticket50 is placed within theticket slot182 in thesensor head218. It should be noted that the excitation and detection circuitry can also be coupled to theticket50 by various other methods including: direct coupling, inductive coupling, radio frequency coupling and optical coupling, as described below in Section IV.E.
• In the preferred embodiment, the[0186]sensor head218 of theelectronic verification machine108 is capacitively coupled to thecircuit81 on theticket50 to complete thecircuit81. A block circuit diagram of the completed circuit225 is shown in FIG. 21. As noted earlier, theconductive areas98A-H, the centralconductive track100, and theconductive bar106 function as capacitor plates. Thesensor head218 includes an array of thecapacitive coupler plates226A-H,228 and230, arranged in the same configuration as theconductive areas98A-H,100 and106. When theticket50 is placed in theticket slot182, thecapacitor plates226A-H are aligned with theconductive areas98A-H, the centralconductive track100, and theconductive bar106 to form capacitors having an air gap dielectric. Alternatively, thecapacitive couplers226A-H,228 and230 could be arranged within theelectronic verification machine108 so that thecapacitor plates226A-H,228 and230 are positioned on the side of theticket50 opposite theconductive areas98A-H,100 and106. In this configuration, the capacitors formed by coupling thecapacitive couplers226A-H,228 and230 to theconductive areas98A-H,100 and106 would have a dielectric contributed both by the air gap and by the ticket substrate and printed layers located between theconductive areas98A-H,100, and106 and thecapacitor plates226A-H,228 and230.
• As noted earlier, each of the resistor tracks[0187]82-96 is capacitively coupled in series to one of thecapacitor plates226A-H in thesensor head218 via one of theconductive areas98A-H. Similarly, a capacitor is formed by thecapacitor plate230 and the centralconductive track100. In addition, the barcode resistor track107 is connected in series with the capacitor formed by thecapacitor plate228 in thesensor head218 and theconductive bars106 and150 and to the capacitor formed by theconductive track104 and thecapacitor plate228.
• The[0188]capacitor plates226A-H and228 are connected to a pair ofbuffer amplifiers232 and236. Themain buffer amplifier236 supplies a signal to anintegrator238 in theelectronic verification machine108 which in turn supplies a signal to themicrocontroller224. Thesecondary buffer amplifier232 provides a feed back loop to thecapacitor plates226A-H and228 and hence theconductive areas98A-H. The resistor tracks which are not currently being tested by theelectronic verification machine108 can produce stray capacitance which would interfere with the measured detection signal. To overcome this effect, thesecondary buffer amplifier232 applies the buffered detection signal to the resistor tracks which are not being tested, such as tracks82-86,90-96, and107, to cancel out the effect of the stray capacitances.
• The[0189]microcontroller224 is also connected to a digital to analog (“D/A”)converter240 which supplies a signal to a voltage controlled oscillator (“VCO”)242. Because of the size constraints of a typical probability game ticket, such asticket50, the capacitance formed by coupling the individual resistor tracks, such asresistor track88, to the excitation and detection circuitry is small. For example, a capacitor including a conductive track printed with the ink formulation described in Table 2 and having an area of 0.201869 inches²would have a capacitance of approximately 9 pF. Consequently, the excitation and detection circuitry includes aninductor244 to oppose the effect of the capacitive impedance resulting from the small capacitance provided by coupling the capacitive pick-upareas98A-98H and104 to theelectronic verification machine108. The output from theVCO242 is routed through theinductor224 and applied to the centralconductive track100 via theexcitation coupler230.
• When the[0190]ticket50 is inserted into theelectronic verification machine108 and themicrocontroller224 is activated, theelectronic verification machine108 begins a discreet verification process for each resistor track82-96 and107. Themicrocontroller224 steps an 8-bit output bus245, which controls the D/A converter240, from a value of 255 to zero. The DC output voltage from the D/A240 is then applied to theVCO242 for conversion to frequency. Thus, themicrocontroller224 produces a stepped series of decreasing excitation frequencies. These stepped excitation frequencies are routed though theinductor244 and applied to the centralconductive track100 of theticket50 via theexcitation coupler230. The excitation signal from theVCO242 is ultimately applied to each of the eight resistor tracks82-96 and the barcode resistor track107. Themicrocontroller224 selects an individual resistor track, such asresistor track88, through solid state switches (not shown) and routes the capacitively coupled detection signal to thedual buffer amplifiers232 and236. Themain buffer amplifier236 supplies a buffered voltage to theintegrator238 which converts the AC detection signal to a DC detection signal and applies this DC detection signal to the analog to digital input of themicrocontroller224 for processing.
• In this embodiment, the[0191]electronic verification machine108 uses a iterative resonance seeking algorithm to determine the measured electrical signature for each of the resistor tracks82-96 and107. Two registers (not shown), the resonance register and the temporary register, in themicrocontroller224 are used to store successive values of the detection signal. The detection signal is the signal produced when any of the resistor tracks, such asresistor track88, is coupled to theelectronic verification machine108 and receives the excitation signal via the centralconductive bar100. The contents of both the resonance and temporary registers are initially set to zero.
• The amplitude of the detection signal is ultimately converted to an eight-bit binary value via the[0192]integrator238 and the A/D input of themicrocontroller224. The binary converted detection signal is then stored in the temporary register of themicrocontroller240 and themicrocontroller240 then compares the contents of the two registers. If the contents of the temporary register is less than the contents of the resonance register, the resonance register contains the binary converted equivalent of the amplitude corresponding to the resonance frequency of the resistor track being tested, such astrack88. Consequently, the frequency of the excitation signal and the contents of the resonance register are output to theprocessor220 and in certain cases to thecommunication interface222 which includes a UART serial digital port. The output of thecommunication interface222 which represents the electrical signature of the resistor track being tested can be transmitted to thecentral computer223 or to a lottery terminal (not shown).
• If the resonance frequency of the resistor track, such as[0193]track88, is not detected, the above excitation and detection process is repeated. First, the contents of the temporary register are stored in the resonance register. Thereafter, the 8-bit output bus, which controls the D/A converter240, is decremented to produce an excitation signal from theVCO242 having a lower frequency than the previously applied excitation signal. The new excitation signal is applied to the ticket via theconductive track100 and the new detection signal is compared, as previously described, with the contents of the resonance register. This excitation and detection process is repeated for each resistor track82-96 and107 until the detection signal corresponding to that associated with the resonance frequency of the resistor track being tested is determined.
• B. Candidate Circuits For Providing The Electrical Signature[0194]
• 1. The T-Square Circuit.[0195]
• Several different types of circuit configurations can be printed on the[0196]ticket50 to provide a measurable electrical signature. In the preferred embodiment, the printedcircuit configuration81, termed a T-square circuit, is illustrated in FIG. 2. As noted earlier, each of the resistor tracks82-96 is electrically connected to one of theconductive areas98A-H and to the centralconductive track100. FIG. 20 is a plan drawing of the partial printed circuit used to determine the authenticity and integrity of the play spot areas72A-H and illustrates the resistor tracks82-96 connected to theconductive areas98A-H and the centralconductive track100. In addition, the barcode resistor track107 is electrically connected to theconductive bars104 and106. FIG. 19 is a plan drawing of the partial printed circuit used to determine the authenticity and integrity of thebar code80 and illustrates the bar coderesistive track107 connected to theconductive areas104 and150. As noted earlier, thefirst layer146 printed on theticket50 includes the barcode resistor track107 and theconductive areas150 and104. Successive layers, up to and including thesixth layer162, do not overlie theconductive area150 thus leaving theconductive area150 exposed. The seventh layer166 consists of the partial printed circuit used to determine the authenticity and integrity of the play spot areas72A-H, as shown in FIG. 20. Theconductive bar106 of theseventh layer164 immediately overlies theconductive bar150 of thefirst layer146. Consequently, the partial circuit including circuit elements82-96 and98A-98H for the play spot areas72A-H, shown in FIG. 20, and the partial circuit for thebar code80, shown in FIG. 19, are electrically connected via theconductive bars106 and150. Thus, when theticket50 is coupled to theelectronic verification machine108, the excitation signal applied to theticket50 via the centralconductive track100 is also transmitted to the bar coderesistive track107 via theconductive bars106 and150. Therefore, the completed circuit225 which is formed when theticket50 is capacitively coupled to thesensor head218 via theconductive areas98A-H,100,104, and106 is actually nine different, separate circuits, one for each of the resistor tracks82-96 and one for the barcode resistor track107.
• As is explained in Section V. below, the[0197]electronic verification device108 tests the integrity of a specific resistor track, such asresistor track88, by comparing the measured resistance to the resistance which should result from the undisturbed configuration of the resistor track as originally printed, that is, the predetermined electrical signature of the resistor track. If the play spot area overlying the resistor track, such astrack88, has not been altered, for example, rubbed off or lifted to reveal the underlying play indicia, the resistance measured by theelectronic verification machine108 will be substantially the same as the resistance which should result from the configuration of theresistor track88 as originally printed. If, however, the play spot has been removed or lifted, the measured resistance will be substantially different than the predetermined electrical signature of thetrack88.
• The T-[0198]square circuit200 can determine the authenticity and integrity of theticket50 as a whole, of the individual play spot areas72A-H, and of thebar code80. If no resistance can be measured for any of the resistor tracks82-96, it can be assumed that either theticket50 is a counterfeit or that all of the play spot areas72A-H have been rubbed off thereby rendering theticket50 void. Moreover, because the T-square circuit200 provides a different individual circuit for each of the resistor tracks82-96, the T-square circuit200 can individually test the integrity of the individual play spot areas72A-H.
• For example, a particular probability game may require revealing three matching game indicia to win. In addition, the game rules may require that no more than three play spot areas be rubbed off to reveal the underlying indicia. Consider the hypothetical situation in which an individual presents the[0199]ticket50 to a lottery agent for redemption because the individual has ostensibly rubbed off only three play spot areas and the indicia in the three play spot areas match. By pure visual inspection, theticket50 might appear to be a valid and winning ticket. However, when theticket50 is inserted into theticket slot182 of theelectronic verification machine108 to measure the resistance of the play spot areas72A-H, theelectronic verification machine108 would determine that not only the measured resistances of the three rubbed-off play spot areas differ from the predetermined resistances for these play spot areas, but also that the measured resistance of other “non-rubbed-off” play spot areas differ from the predetermined resistances for these areas. This situation could arise, for example, when the individual removes theoverprint areas68 of these additional play spot areas to reveal the hiddenindicia74 and then attempts to replace theoverprint areas68 so that these play spot areas appear to not have been played. Thus, although visually theticket50 appears to be a valid winning ticket, the measure of the resistances82-96 would indicate that more than three play spot areas have been removed and that therefore theticket50 is void. In addition, if the measured resistance of the barcode resistor track107 is substantially different from the predetermined electrical signature for thebar code80. it can be assumed that thebar code80 has been tampered with as well.
• 2. The Binary Coupled Circuit.[0200]
• An alternative embodiment of a[0201]ticket250 having a partial printedcircuit252, termed a binary coupled circuit, is shown in FIG. 21. Thepartial circuit252 is analogous to theseventh layer164 printed on theticket50. As withticket50, thepartial circuit252 is ultimately printed on aticket substrate254 preferably using a conductive ink of the type described in Table 2. Although not shown, it is to be understood that additional layers such as a lower conductive layer analogous to thefirst layer146 ofticket50, a blocking layer and a primer layer analogous to thesecond layer156 andthird layer158 of theticket50, play indicia analogous to the play indicia74 ofticket50, a seal coat and release coats analogous to thefourth layer160 and the fifth andsixth layers162 of theticket50 are also printed on theticket250 between thesubstrate254 and thepartial circuit252 in a manner similar to that used forticket50.
• The[0202]ticket250 includes adisplay portion256 and aplaying field portion258. Thedisplay portion256 is ultimately covered by a coating (not shown) suitable for receiving customized graphics (not shown) and information (not shown) related to the rules for playing theticket250. The playing field portion includes two columns of four, separately removable play spot areas260-274. Within theplaying field portion258, the partial circuit includes several conductive areas276-292 and eight resistor tracks294-308. Each of the play spot areas260-274 is positioned between two conductive areas, for example, playspot area260 is positioned betweenconductive areas276 and278 and playspot area262 is positioned betweenconductive areas278 and280. Each of the resistor tracks294-308 is also positioned between and electrically connected to two of the conductive areas276-292. For example,resistor track294, associated withplay spot area260, is positioned between and connected toconductive areas276 and278. Underlying each of the play spot areas260-274 is a conductive line (not shown). Each conductive line is connected to the two conductive areas associated with its respective play spot area and resistor track. For example, the conductive line underlyingplay spot area260 is connected toconductive areas276 and278.
• The three additional conductive areas[0203]310-314 are printed in thedisplay portion256 of theticket250. The firstconductive area310 is connected to the first column of four play spots269-266 via aconductive track316 connected to theconductive area284. The secondconductive area312 is connected to the second column of four play spots268-274 via a secondconductive track318 connected to theconductive area292. All eight play spot areas260-274 are connected to the thirdconductive area314 via a thirdconductive track320 connected to theconductive area276. The conductive areas310-314 serve as capacitor plates when theticket250 is coupled to an electronic verification machine.
• Each column of four play spot areas[0204]260-266 and268-274 forms one complete circuit when theticket250 is coupled to theelectronic verification machine108. The excitation signal from theelectronic verification machine108 is routed through each group of four play spot areas260-266 via the commonconductive area314 in thedisplay portion256 of theticket250. Each group of four play spot areas260-266 and268-274 provides its own detection signal. The detection signal for the play spot areas260-266 is coupled to theelectronic verification machine108 via theconductive track316 and theconductive area310. The detection signal for play spot areas268-274 is coupled to theelectronic verification machine108 via theconductive track318 and theconductive area312.
• Within a group of four play spot areas, for example play spot areas[0205]260-266, the magnitude of the detection signal varies with the integrity of each of the play spot areas260-266. If the play spot areas260-266 are intact, the excitation signal is substantially unaltered and is routed through the conductive lines underlying each of the play spot areas260-266. However, if a play spot area has been rubbed off or lifted to reveal the underlying play indicia, the signal is routed through the resistor track associated with that play spot area. For example, ifplay spot area260 is intact, the signal proceeds through the underlying conductive bar to theconductive area278. However, if theplay spot area260 has been at least partially removed to reveal the underlying play indicia, the circuit through the conductive line is broken thus routing the signal through the associatedresistor track294 thus changing the characteristics of the detection signal.
• In the preferred embodiment of this[0206]ticket250, each of the resistor tracks associated with a group of four play spot areas, such as the resistor tracks294-300 associated with play spot areas260-266 has a unique predetermined resistance that is related, in a binomial progression, to the other resistor tracks in the column. For example,resistor track294 can have a predetermined electrical signature equal to a resistance of 100 KΩ,resistor track296 can have a predetermined electrical signature equal to a resistance of 200 KΩ,resistor track298 can have a predetermined electrical signature equal to a resistance of 400 KΩ, andresistor track300 can have a predetermined electrical signature equal to a resistance of 800 KΩ. The resistor tracks, such as resistor tracks294-300, are printed in parallel to the conductive lines underlying the play spot areas, such as play spot areas260-266. As explained below, the binomial relationship of the printed resistances for each resistor track within a group of four resistors tracks permits determination of the integrity of each play spot even though only one detection signal is produced for all four resistor tracks.
• FIG. 22 is a partial schematic circuit diagram[0207]324 illustrating the coupling of one column of four resistor tracks260-266 to the excitation and detection circuitry of theelectronic verification machine108. The parts of the circuit which are contributed by theticket250 include the four resistor tracks294-300, the conductive areas276-284, theconductive lines316 and320, and theconductive areas314 and310. In addition, the ticket partial circuit includes four conductive lines326-332 which underlie the play spot areas260-266. The play spot areas260-266 do not actually form a part of the circuit but are included in FIG. 22 for ease of understanding.
• The remainder of the excitation and detection circuit is provided by the[0208]electronic verification machine108, including a pair ofcapacitor plates334 and336. Thecapacitor plates334 and336 can consist of, for example, copper plates positioned within theelectronic verification machine108 to mirror the configuration of the conductive areas, such asconductive areas310 and314, on theticket250. When theticket250 is coupled to the electronic verification machine, the excitation and detection circuit is completed by the capacitive coupling of thecapacitor plates334 and336 in the electronic verification machine with theconductive areas314 and318 printed on theticket250. The excitation signal is applied to theticket250 via one of the capacitors formed by one of the capacitor plates, for example thecapacitor334, with theconductive area314 printed on theticket250. The detection signal is routed to the rest of the excitation and detection circuit via the capacitor formed by the other capacitor plate in the electronic verification machine, for example plate338, with theconductive area310 printed on theticket250.
• When the play spots[0209]260-266 have not been removed or tampered with, as illustrated in FIG. 22, the excitation signal flows through the each of the four conductive lines326-332. However, removing or partially removing one of the play spots260-266 effectively breaks the circuit through the associated conductive line rerouting the signal through the associated resistor track. For example, ifplay spot260 is removed, the signal pathway would go throughresistor track294. Because each resistor track294-300 has its own unique resistance, each resistor track294-300 produces its own unique detection signal thereby permitting theelectronic verification machine108 to identify which, if any of the play spot areas260-266 have been lifted or removed. Moreover, since the resistance values of the resistor tracks294-300 are related to each other as a binomial progression, theelectronic verification machine108 can also identify which of the play spots260-266 have been removed when two or more of the play spots260-266 have been removed. For example, if both playspots260 and262 are removed the combination ofresistor tracks294 and296 adds 300 KΩ to the excitation and detection circuit. However, if play spots260 and264 are removed, the combination ofresistor tracks294 and298 adds 500 kΩ to the excitation and detection circuit. Thus, because the resistor tracks294-300 have resistance values that are related as a binomial progression, each possible combination of resistor tracks294-300 results in a unique total resistance which can be used to identify the play spots260-266 that have been removed. Table 3 lists all the possible combinations of resistor tracks294-300 and the resulting resistance values for the previously identified resistance values for the resistor tracks294-300.

  TABLE 3
  Resistor Combinations

  	Resistors In The Circuit	Effective Resistance

  R1

  	100
  	R2	200
  	R3	400
  	R4	800
  	R1 +R2	300
  	R1 +R3	500
  	R2 +R3	600
  	R1 + R2 +R3	700
  	R1 + R4	900
  	R2 +R4	1000
  	R1 + R2 +R4	1100
  	R3 + R4	1200
  	R1 + R3 + R4	1300
  	R2 + R3 + R4	1400
  	R1 + R2 + R3 + R4	1500

• Additional resistance values and combinations of resistance values are possible. For example, the resistance values in Table 3 could be increased or decreased by an order of magnitude. The principle of this circuit design is that the individual resistance of each resistor track within a group of resistor tracks, such as resistor tracks[0210]294-300, should be algorithmically related to the resistances of the other resistor tracks within the group so that every combination of resistor tracks provides a unique total resistance. Preferably, the individual resistances should vary as a binomial progression.
• 3. The Infinite Resistance Circuit.[0211]
• FIGS. 23, 24,[0212]25 and26 illustrate another partial printed circuit which can be used to validate and determine the authenticity and integrity of a document which in this example is alottery ticket340. As shown in FIG. 23, the lottery ticket includes playindicia342 which are printed over theticket substrate344. Additional information, such as the name of thelottery game346 andrules348 for playing the ticket are also printed on theticket substrate344. FIG. 24 is a plan drawing of the scratch-off coating350 which is printed over and conceals theplay indicia342. The scratch-off coating350 is a removable layer of a material such as latex which can be relatively easily removed to reveal theplay indicia342. A single block of scratch-off coating350 is used to cover all of theplay indicia342. A release coat (not shown) coincident with the scratch-off coating350 is also printed on theticket340 between theplay indicia342 and the scratch-off coating350. FIG. 25 is a plan drawing of the partial printed circuit which is used to determine the integrity and authenticity of theticket340. The circuit consists of a single conductive area indicated at352A and352B which overlies the scratch-off coating350. The twoportions352A,352B of the conductive area extend beyond the edges of the scratch-off coating350. FIG. 26 is a plan drawing of theticket340 in its final printed state which includesoverprint areas354 that conceal the scratch-off coating350 and the conductive area352, as well asoverprint areas356 that define the individual play spot areas.
• When the[0213]ticket340 is coupled to theelectronic verification machine108 theportions352A and352B serve as capacitor plates to couple the partial circuit printed on theticket340 with the excitation and detection circuitry in theelectronic verification machine108. The portion of theconductive track352A-B which immediately overlies the scratch-off coating350 but does not extend beyond the scratch-off coating350 serves as a resistor track when theticket340 is coupled to anelectronic verification machine108. If the ticket is in its original integral state, the portion of theconductive area352A-B immediately overlying the scratch-off layer350 is electrically connected to theportions352A and352B which serve as capacitor plates. However, if an individual has attempted to surreptitiously inspect theplay indicia342 by, for example, lifting and then replacing the scratch-off layer350, the electrical connection between the middle portion of the conductive layer and theend portion352A and352B would be broken resulting in an open circuit.
• 4. The Increased Resistance Circuit.[0214]
• FIG. 27 illustrates an alternative embodiment of a scratch-[0215]off layer358 for theticket340. Unlike the previously described scratch-off layer350, the scratch-off layer358 consists of discreet, individual areas which overlie each play indicia342 (not shown). A release coat (not shown) underlies each of the discreet portions of the scratch-off coating358. The partial printed circuit which overlies the scratch offlayer358 consists of a single conductive area indicated at360A and360B which overlies all of the scratch offlayer358. Twoportions360A,360B of the conductive area360 extend beyond the area of theticket340 containing the scratch-off coating358. The final printed format of theticket240 is shown in FIG. 26 and includesoverprint areas354 that conceal the scratch-off coating358 and theconductive area360A-B, as well asoverprint areas356 that define the individual play spot areas.
• When the[0216]ticket340 is coupled to anelectronic verification machine108, theportions360A and360B of the conductive area360 which extend beyond area of theticket340 containing the scratch-off layer358 serve as capacitor plates to couple the partial circuit printed on theticket340 with the excitation and detection circuitry in theelectronic verification machine108. The portion of theconductive area360A-B which immediately overlies the scratch-off coating358 but does not extend beyond the scratch-off coating358 serves as a resistor track when theticket340 is coupled to theelectronic verification machine108. If all of the play spots are intact, the electrical signature of theticket340 will be equal to the printed resistance associated with the portion of the conductive track360 which overlies all of theplay indicia342. However, if an individual has attempted to surreptitiously inspect theplay indicia342 by, for example, lifting and then replacing one portion of the scratch-off layer358, the small portion of theconductive area360A-B immediately overlying the removed area of the scratch-off layer258, will be electrically disconnected from the remainder of theconductive area360A-B, leading to an increase in the resistance associated with theconductive area360A-B.
• 5. The Waffle Circuit.[0217]
• FIG. 29 is a plan drawing of another[0218]partial circuit364 which can be printed on a lottery ticket to determine the authenticity and integrity of the play spot areas. The partial circuit, termed a waffle circuit, includes twoconductive bars366 and368 which are electrically connected to aconductive area370 overlying the play indicia (not shown). Removable scratch-offareas372 overlie the portions of theconductive area370 which immediately overlie the individual play indicia. A seal coat and release coats analogous to theforth layer160 and the fifth andsixth layers162 of theticket50 in FIG. 11 are printed in an appropriate configuration between the play indicia and theconductive area370. Thus, removal of any of the scratch-offareas372 also removes a portion of theconductive area370. When the ticket which includes thepartial circuit364 is coupled to theelectronic verification machine108, each of the play spot areas defined by the scratch-offareas372 serves as a capacitor plate. In addition, theconductive bars366 and368 also serve as capacitor plates to couple thepartial circuit364 to the excitation and detection circuitry of theelectronic verification machine108. The excitation and detection circuitry of theelectronic verification machine108 in turn includes an array of capacitive couplers which are positioned to mirror the configuration of theconductive bars366 and368 and the scratch-offareas372. Thus, in contrast to the previously described partial circuits in FIGS. 20, 21, and23-28, the electrical signature of the play spot areas associated with thepartial circuit364 is a conductive track, rather than a resistive track.
• The[0219]electronic verification machine108 can check the authenticity and integrity of the play spot areas defined by the scratch-offareas372 by applying an AC excitation signal to one of theconductive bars366 or368. If the individual play spot area being tested is intact, the excitation signal will be routed through the portion of theconductive area370 underlying the scratch-off area372 associated with the tested play spot area. Consequently, an AC detection signal will be routed to the capacitor plate in theelectronic verification machine108 which mirrors the particularplay spot area372. However, if the scratch-off area372 being tested has been at least partially removed, the associated removal of a portion of theconductive area370 creates an open circuit under that particular scratch-off area372. Hence, no AC detection signal is routed to the associated capacitor plate in theelectronic verification machine108, indicating that the integrity of theplay spot area372 has been changed.
• 6. The Recursive Circuit.[0220]
• FIG. 30 is another plan drawing of a partial printed[0221]circuit376 which can be used to determine the authenticity and integrity of the play spot areas of a lottery ticket. Thepartial circuit376 includes resistor tracks (not shown) which underlie each of the removable scratch-offareas378. Each resistor track is electrically connected to a pair ofconductive bars380A and380B. In the partial circuit shown in FIG. 30, there are a total of twenty-fourconductive bars380A,380B, two for every resistor track associated with one of the scratch-offareas378. When the ticket which includes thepartial circuit376 is coupled to anelectronic verification machine108, each resistor track associated with each scratch-off area378 is capacitively coupled to the excitation and detection circuity of theelectronic verification machine108 by its associatedconductive bars380A and380B. One conductive bar, for example, bar380A, is used to apply the excitation signal to the resistor track. The second conductive bar, forexample bar380B, routes the detection signal to the rest of the excitation and detection circuitry in theelectronic verification machine108. If the scratch-off area372 being tested is intact, the electrical signature of the associated resistor track will be substantially equal to the printed resistance of the resistor track underlying the scratch-off area372. If, however, the scratch-off area372 being tested has been at least partially removed or lifted, the measured resistance of the resistor track and hence the resonant frequency of the completed circuit associated with the scratch-off area372 will be substantially different than the printed resistance of the resistor track.
• C. Variation In Printed Resistances[0222]
• 1. Variations In The Printed Resistances.[0223]
• A number of the foregoing circuits, such as the T-square circuit shown in FIG. 20., and the binary-weighted circuit shown in FIG. 21, use the resistance of a printed resistor track to impart an electrical signature to a document. As noted earlier, the resistance of such printed resistor tracks can be defined as follows:[0224]
• R=ρ(L/A)
• where R=resistance;[0225]
• ρ=bulk resistivity (resistance per unit volume);[0226]
• L=length of resistor; and[0227]
• A=cross sectional area of the resistor.[0228]
• The cross-sectional area of the resistor in turn equals the product of the print thickness (t) and the width (W) of the resistor. Substituting these parameters yields the following formula for the resistance of a printed resistor track:[0229]
• R=ρ(L/tW)
• Thus the resistance of a printed resistor track such as those used in the previously described circuits is a function of the bulk resistivity of the ink used to print the resistor, the length of the resistor track, the thickness of the printed track and the width of the printed track. Resistor tracks having different resistances can thus be formulated by varying any of these parameters. In practice, changing the resistivity of the inks used in order to create different resistor tracks having different resistances may be impractical because, at least in a gravure printing process, changing inks requires using a different printing station. The other parameters, however, can be easily and effectively varied to provide different resistor tracks within one circuit which have different resistances. FIG. 31 is a plan drawing of four different resistor tracks[0230]384-390. Because the length and widths of the resistor tracks384-390 differ, the resistances of the resistor tracks384-390 will be different even if the resistor tracks384-390 are printed with exactly the same conductive ink. Thus, for example, the resistor tracks386 and388 would have different resistances even though the lengths of the resistor tracks386 and388 are approximately equal because the widths of the resistor tracks386 and388 are not the same. Thus, the resistance of the resistor tracks printed on a document, such as theticket50, can be varied by varying the dimensions of the printed resistor tracks.
• 2. Variations In The Measured Resistances.[0231]
• Variations in ink resistivity can also occur over the course of a large print run. These variations in resistivity are due to a number of factors including printing process temperature and viscosity variations. Consequently, these variations are only detectable over a large number of tickets that were printed over a long period of time. The resistivity of the ink on a single ticket does not fluctuate in this manner. However, the resistance of a resistor track printed at the beginning of a print run can be measurably different than the resistance of an identical resistor track printed with the same conductive ink at the end of a print run due to these time-dependent variations in the resistivity of the conductive ink. Consequently, it is desirable that these time dependent variations in the electrical signature be compensated for when the[0232]electronic verification machine108 tests the authenticity and integrity of the document.
• The electronic verification machine, such as[0233]electronic verification machine108, compensates for such time-dependent variations in the measured electrical signature in one or both of two ways: (1) by establishing that the measured values are accurate within a specified range of an expected value; or (2) by using a separate circuit element to establish the precision of the measured electrical signature.
• In the preferred embodiment, the electronic verification machine compensates for time dependent variations in the electrical signature by determining that the measured values are accurate within a range of, for example, 10 percent, of the expected electrical signature. Thus, for example, a measured resistance that is expected to be 500Ω would be acceptable as long as the resistance was in the range between 450Ω and 550Ω. In other words, if the measured resistance was within this range, the corresponding play spot is treated by the[0234]electronic verification machine108 as not having been rubbed off and therefore as being in its original integral state as well as presumably authentic.
• If the time dependent variations in the electrical signature are corrected by using a precision system, the partial circuit printed on the ticket must contain an additional element, a calibration line, which is used to determine if a measured resistance is precise. FIG. 32 is a plan drawing of an alternative embodiment of a T-[0235]square circuit392 which includes a calibration line shown generally at394. Thecalibration line394, termed a John Galt line, includes aresistor track396 connected to aconductive area398. The remaining elements of the partial printedcircuit392 are analogous to and function in the same manner as the T-square circuit shown in FIG. 20. Hence, the remaining elements of thecircuit392 in FIG. 32 correspond to the circuit elements shown in FIG. 20. Thecalibration line394 is connected to the rest of thecircuit392 via the centralconductive area100. Theresistor track396 is printed on a portion of the ticket which does not include play spot areas. Consequently, theresistor track396 should remain in its original integral state after the ticket has been played. When a ticket containing thecalibration line394 is coupled to theelectronic verification machine108 theresistor track396 is coupled to the excitation and detection circuitry of theelectronic verification machine108 by the capacitors formed by coupling theconductive areas100 and398 to capacitor plates in theelectronic verification machine108.
• In the[0236]partial circuit392 shown in FIG. 32, thecalibration line394 is used to determine how far the measured resistances of a particular ticket should deviate from the expected value for these resistances. For example, if thecalibration line394 is printed with an expected resistance of 500Ω, but measured resistance of thecalibration line394 on a particular ticket actually has a calibration value resistance of 525Ω, the five percent increase over the expected value should be seen in other resistances on the card as well. Therefore, even if a measured resistance of a play spot area is within the acceptable value of 10 percent above or below the expected value, it should be approximately five percent higher than the expected value in order to be precise for this ticket. Thus, if a given resistance corresponding to one of the play spots is eight percent below the expected value and therefore within plus or minus ten percent of the expected resistance, the spot would be deemed to have been played because the resistance, although accurate, is not within the calibrated precision for this ticket.
• D. Protection Of The Bar Code[0237]
• A circuit printed on a lottery ticket, such as the[0238]circuit81 printed on theticket50 shown in FIG. 2, can include a partial printed circuit which provides an electrical signature to protect thebar code80. As noted with reference to FIG. 19, the bar code partial circuit includes aresistor track107 connected to twoconductive areas150 and104. In addition, theconductive area150 immediately underlies theconductive area106 of the partial printedcircuit164 used to determine the authenticity and integrity of the play spot areas, as shown in FIGS.2 and G. Hence the partial printed circuit for thebar code80 and the partial printedcircuit164 for the play spot areas are electrically connected via the overlying relationship of theconductive areas106 and150. Consequently, when theelectronic verification machine108 transmits the excitation signal to theticket50 via the centralconductive track100, the excitation signal can be routed to the bar code partial circuit via theconductive areas106 and150. The detection signal from thebar code80 is routed to the remaining excitation and detection circuitry via the capacitor formed by theconductive area104 and a capacitor plate in theelectronic verification machine108.
• The[0239]bar code80 is in turn printed on theticket50 to at least partially overlie the bar code partial circuit. In the preferred embodiment shown in FIGS. 1 and 2, thebar code80 is printed on theticket50 so that it overlies theconductive area104. Alternatively, thebar code80 could be printed to overlie theresistor track107. In either embodiment, attempts to alter thebar code80, for example by substituting thebar code80 of the ticket with the bar code of a different ticket, would result in changes in the measured electrical signature of thebar code80 by changing either the resistance or the capacitance of the bar code partial circuit.
• E. Alternative Circuit Designs[0240]
• In addition to resistors, other types of electrical circuit elements can be used in a printed circuit to produce electrical circuits. For example, the elements used to couple a document, such as the[0241]ticket50, to anelectronic verification machine108 are not limited to capacitor plates or areas but can also include inductive, radio frequency, and optical frequency circuit elements. In addition, the form of the electrical signature can be varied so that a properties other than resistance can be used to validate or determine the authenticity and integrity of a document. Examples of alternative electrical signatures include gain, amplitude, frequency, oscillation, and thermal effects.
• 1. Coupling[0242]
• There are a number of methods by which a circuit printed on a document, such as the[0243]circuit81 on theticket50, can be coupled to theelectronic verification machine108 including direct, capacitive, inductive, radio frequency and optical coupling methods. In direct coupling, the ticket is coupled to the electronic verification machine via direct physical contact of one or more conductive areas on the ticket with an electrical element, such as a contact plate, within theelectronic verification machine108. Although it is relatively straightforward to implement, direct coupling has the potential disadvantage of signal distortions which can arise from surface imperfections or impurities on the conductive areas of the ticket.
• In capacitive coupling one or more conductive areas such as the[0244]areas98A-H of theticket50 shown in FIG. 2 form one plate of a capacitor. The other plate of the capacitor is provided by a metal plate connected to the circuitry of theelectronic verification machine108. As described previously, the resulting capacitor can be used to form part of a verification circuit225 as shown in the block diagram of FIG. 18. Here theconductive areas98A-C of theticket50 form capacitors with the plates200-204 of theelectronic verification machine108.
• Inductive coupling is similar in that a[0245]ticket400 is printed with a circularconductive area402 as illustrated in the example of FIG. 33. Theelectronic verification machine108 would then include acoil404 that is inductively coupled with the circularconductive area402 when theticket400 is inserted in theelectronic verification machine108. There are a variety of configurations that can be used including a number of inductors printed on theticket400 that would be inductively coupled with a corresponding number of coils in theelectronic verification machine108.
• Radio frequency can also be used for verification as shown in FIG. 34. In this case a[0246]planar transmission line406 is printed on aticket408 which is separated by theticket substrate410 from aground plane412 printed on the other side of thesubstrate410. With this structure radio frequency energy is transmitted and received in a transverse electromagnetic mode. Using this approach verification signals can be transmitted to the circuits printed on theticket408 from suitable antennas located in theelectronic verification machine108.
• In addition, optical frequency can be used for verification where for example a photo emitter conductor or semiconductor is printed on the[0247]ticket50 and is electrically stimulated to emit light at an infrared frequency. Photo-detectors on theelectronic verification machine108 can be used to detect and classify the frequency of the light emitted by theticket50 in contrast to the nominal reflective background of theticket50.
• 2. Signature Verification[0248]
• There are a number of methods for verifying the authenticity or integrity as well as to determine the redemption value of a lottery ticket, such as the[0249]ticket50, using theelectronic verification machine108. One method is to merely check for an open circuit in the circuit printed on theticket50. Here a signal is applied to the ticket circuit by one of the techniques described above and if no current flow is detected then it can be assumed that a play spot72A-H has been removed or that the ticket has been tampered with.
• Gain can also be used where the[0250]electronic verification machine108 includes an operational amplifier and the circuit element printed on theticket50 serves in its feedback loop. The gain of the operational amplifier will reflect any changes in the ticket circuit and thus can be used to detect tampering or to determine which play spots72A-H have been scratched off by the player.
• The amplitude of the voltage, current or power of the AC signal flowing through circuit printed on the[0251]ticket50 can additionally be measured by theelectronic verification machine108 to indicated changes in the circuit that would reflect alterations in theticket50.
• The phase of a signal flowing thought the circuit printed on the[0252]ticket50 can also be checked by theelectronic verification machine108 against an expected or predetermined value to determine changes in the circuit.
• Frequency of the electrical signal induced in the circuit printed on the ticket can be measured by the electronic verification machine to detect changes in the ticket. This is an especially useful approach where the circuit on the[0253]ticket50 includes elements such as capacitors or inductors which can affect frequency.
• A measure of oscillation frequency can also be used where the circuit printed on the ticket combined with the circuit in the electronic verification machine forms[0254]108 an oscillator or where a complete oscillator circuit is printed on theticket50. Here an expected oscillation frequency can be used to detect changes in theticket50.
• It should be noted that other methods can be used to determine which of the play spots[0255]72A-H of theprobability ticket50 have been scratched off. For example, an optical card reader system of the type described in U.S. Pat. Nos. 4,736,109 and 4,760,247 or a laser system of U.S. Pat. No. 5,903,340 can be used to read a security code imprinted on theoverprint areas66 ofticket50 to determine which of the play spots have been rubbed off in the manner generally described in U.S. Pat. No. 5,887,906. These systems can then perform the function of thesensor arrays502 and1036 and the related circuits of FIGS. 38 and 99 respectively, as described in connection with those figures below, to determine if the play spots72 A-H have been rubbed off.
• Thermal effects are another phenomena that can be used by the system described above to detect tampering or determine which play spots have been removed from a[0256]ticket414 of the type shown in FIG. 35. In this case heat generated by current flowing though a set ofresistors416A-D is detected by a group ofinfrared photodetectors418A-D located in theelectronic verification machine108. When one or more of a set of play spots420A-D is removed current will no longer flow though its associated resistor and the resulting lack of infrared radiation would indicate that the spot(s) had been removed.
• Capacitance and inductance changes in the circuits printed on the[0257]ticket50 can likewise be detected by theelectronic verification machine108 indirectly from the frequency characteristics of the circuits in order to determine whether changes have occurred on theticket50.
• V. Validation of Lottery Tickets[0258]
• Validation of the[0259]lottery ticket50 as well as the determination the authenticity and integrity of a document, such asticket50, can involve the interaction of several steps. As an example, a description of a preferred method for validating thelottery ticket50 of FIG. 1 using theelectronic verification machine108 of FIG. 14 is provided below. When an individual presents theticket50 to a lottery agent for redemption, the lottery agent insert theticket50 into theelectronic verification machine108. The electronic verification machine will read thebar code80, which contains the inventory control number and encrypted validation number data, and it will sense which of the play spots72A-G have been removed. The lottery agent then enters thevalidation number78 of theticket50 into theelectronic verification machine108 via theuser interface178. As noted earlier, thevalidation number78 contains information related to the identity of a specific ticket, such as the pack and ticket number. In addition, in the preferred embodiment thevalidation number78 also contains information related to the electrical signatures of the circuit elements printed on theticket50. For example, theticket50 has two electrical signatures. One signature is the expected resistance of the barcode resistor track107. The second is the expected resistance of the play spot resistor tracks82-96 which all have the same value. If the play spot resistor tracks had different expected values, such as the resistor tracks294-308 in thepartial circuit292 shown in FIG. 21, information related to each electrical signature could be stored in thevalidation number78 of theticket50. Alternatively, the information related to the electrical signature(s) of the circuit elements printed on theticket50 could be stored in a look-up table in the microprocessor on theprocessor board220 in theelectronic verification machine108 or thecentral computer223. In this case, thevalidation number78 or the encrypted validation number printed in thebar code80 is used primarily to correlate the particular ticket being tested with the electrical signature information stored in the computer. Alternatively, data related to the expected signal can be contained in thevalidation number78. In either case, the validation number provides the primary method for accessing the information related to the expected electrical signature(s) of the ticket.
• After the[0260]ticket50 is coupled to theelectronic verification machine108 via theticket interface176, theelectronic verification machine108 completes the discreet verification process for each of the play spot resistor tracks82-96, as explained above in Section IV.A. The electronic verification machine determines the measured electrical signature for each of the play spot resistor tracks82-96 and compares these values to the value or values stored either in thevalidation number78 of theticket50 or in a look-up table in thecentral computer223 or theprocessor board220. If the measured resistance of a specific play spot resistor track82-96 is substantially the same as the stored value of the resistance, the associated play spot area72A-G is in its original integral state and has not been at least partially removed. If, on the other hand, the measured resistance is substantially different than the stored value for the resistance, the associated play spot area72A-G is treated by theelectronic verification machine108 as having been removed. This occurs, for example, when the associated play spot area has been at least partially removed by a player playing the ticket or when the ticket has been tamped with.
• In this particular example, the[0261]ticket50 is considered valid only if the number of play spot areas72A-G specified in therules58 have been removed to reveal theunderlying play indicia74. For example, therules58 for a particular game may require rubbing off only three play spot areas72A-G. If an individual rubs off more than three play spot areas72A-G, theticket50 is void even if three of the revealedplay indicia74 match. If theelectronic verification machine108 determines that theticket50 is valid, that is theticket50 has been played according to therules58, theelectronic verification machine108 then proceeds to determine the redemption value of theticket50.
• The[0262]electronic verification machine108 can validate or determine the redemption value of the ticket, such asticket50, in either of two ways: (1) by accessing the play indicia value data stored in thebar code80 on theticket50; or (2) by accessing a ticket redemption file contained in thecentral computer223 or theprocessor220. Storing the play indicia value data in thebar code80 has the advantage of permitting local determination of the redemption value of theticket50. Consequently, any lottery terminal can determine the redemption value of a ticket without contacting a central lottery or host computer thus reducing the cost and time required in the redemption process. On the other hand, it is not inconceivable that the play spot value code in thebar code80 could be broken even though there are a very large number of potential play spot value combinations that can be printed on theticket50. As a result there is some possibility that an individual could predict the winning combinations present onticket50 based upon thebar code80. Maintaining a separate ticket redemption value file in thecentral computer223 or theprocessor220 will normally result in increased ticket security because the play indicia value data are not stored in abar code80 on theticket50. Such a system, however, requires communication with thecentral computer223 or theprocessor220 in theelectronic verification machine108 before theticket50 can be redeemed. As a result, this type of redemption process, especially where a remotecentral computer223 is used, can be slower and more costly than storing the play indicia value data in the bar code.
• In the preferred embodiment of the invention, therefore, the method of storing play indicia or redemption value data in the[0263]bar code80 typically would be used only for low level prizes. The larger cash prizes would be computed by the lotterycentral computer223 in order to increase the security of the system with respect to high tier prizes or redemption values. In this embodiment, thebar code80 would store information concerning all the play indicia74 on theticket50. Thebar code80 can consist of, for example, 22 digits which represent a game number (2 digits), a pack number (6 digits), a check digit (1 digit), a ticket number (3 digits) and a play spot code (10 digits). The game number is unique to each particular lottery game. The pack number identifies the pack from which a particular ticket originates. The check digit is used to help ensure that a proper bar code read has been made. The ticket number relates the relative position of a specific ticket within a pack. In this example, the game number, the pack number and the ticket number represent ticket identification or accounting data and normally in themselves do not contain redemption value information.
• The 10-digit play spot code includes a value portion containing information about the value of each of the play indicia of each of the play spots areas. An illustration of how such a 10-digit play spot code can be used in a[0264]probability lottery ticket422 is provided in FIGS. 36 and 37. Referring to FIG. 36, theticket422 has sixteenplay spots areas424A-P each of which covers a play indicia426A-P which are shown in FIG. 37. Theticket422 also includes abar code428 and a void-if-removedarea430 which conceals a validation number (not shown) as well as a set of printedinformation432 concerning the rules for playing theticket432. In the example illustrated in FIGS. 36 and 37, therules432 state that only sixplay spot areas424A-P may be removed. Theticket422 can be redeemed for a prize if any two of the revealed play indicia426A-P match. FIG. 37 illustrates theticket422 after all of theplay spot areas424A-P have been removed to reveal the underlying play indicia426A-P.
• For a ticket with 16 play spots areas, such as the[0265]ticket422, two bits of the value portion in the play spot code are used to store information concerning the value of the play indicia426A-P for eachplay spot area424A-P. In this example, the values of these bit pairs are as follows: “00” signifies that the value of the play spot area cannot be checked locally by theelectronic verification machine108; “01” signifies that the value of the play indicia equals $1.00; “10” indicates that the value of the play indicia equals $2.00; and “11” indicates that the value of the play indicia equals $5.00. In other words, all play indicia that contain the $1 symbol are represented by the bit pattern “01”, play indicia that contain a $2 symbol are represented by the bit pattern “10 ”, and play indicia that contain the $5 symbol are represented by the “11” bit pattern. Any play indicia having a value other than $1, $2 or $5 has a corresponding bit pattern of “00”. Thus, for example, all play spots having $10, $20, $50 or $100 symbols would have corresponding bit patterns of “00”. The bit pattern “00” indicates that the play indicia value for the correspondingplay spot area424A-P cannot be determined locally and must be determined by accessing the redemption file in thecentral computer223. The bit patterns for all of the play indicia426A-P are strung together to form a 32-bit binary number. For example, the 32-bit binary number corresponding to the play indicia426A-P would be as follows:
• 11 00 00 00 00 11 00 00 00 00 11 00 00 00 00 01[0266]
• This binary number then is converted to[0267]base 10 in which the 32-bit number is represented by 10 digits, in this case 3,224,374,273. These 10 digits are encrypted to form the play spot code which forms a part of thebar code428. It should be noted that the 32-bit binary number can also be converted to numbers having other bases such as hexadecimal. For example, the hexadecimal value of the above 32-bit binary number would be C0300C01.
• The[0268]bar code reader210 in theelectronic verification machine108 reads thebar code428 including the play spot code. The computer on theprocessor board220 in theelectronic verification machine108 decrypts the 10 digit,base 10 play spot code and then converts it to a binary number thereby creating a 32-bit number with a 2-bit code corresponding to each of the 16play indicia426A-P. The computer in theelectronic verification machine108 then compares the two-bit pattern stored in the play spot code for eachplay spot area424A-P which has been previously determined by the detection circuitry of theelectronic verification machine108 as having been played. If two or more of the rubbed-off play spot areas have a value of “00” (i.e., “can't check locally”), theelectronic verification machine108 can not determine locally whether theticket422 is a winner of a high tier prize and if so, the redemption value of theticket422. Thus, in theexemplary ticket422 illustrated in FIGS. 36 and 37, if the bit pattern for any of the revealed play indicia426A-P matches the bit pattern for a second revealed play indicia426A-P, the redemption value of theticket422 equals the value of the matching play indicia426A-P. For example, if two of the revealed play indicia426A-P have a bit pattern equal to “11”, the redemption value of theticket422 is five dollars. Theelectronic verification machine108 then informs the lottery agent of the redemption value of theticket422 via thedisplay180 or theprinter181 so that theticket50 can be paid.
• If two of the entries in the table corresponding to the rubbed-off spots are “00”, however, the[0269]electronic verification machine108 will not be able to locally determine the redemption value of theticket422. Here the “00” bit pattern indicates that the rubbed-off play spots represent a high redemption value or that there may be more than one possible redemption value, for example, the value of all play indicia greater than five dollars. In this case, theelectronic verification machine108 accesses the ticket redemption file in thecentral computer223 to determine the redemption value of theticket422. In one arrangement the redemption file in thecentral computer223 contains a record or a list for eachticket422 in which the play indica value data are stored in association with a ticket identity number. The ticket identity number, for example accounting data contained in thebar code428 or contained in aconventional validation number78, which uniquely identifies a ticket within a game is transmitted to thecentral computer223 and can be used as an address to locate the record in the redemption file containing the indica or redemption values for that ticket. Thus, for example, the ticket redemption file for theticket422 includes play indicia value data which enables thecentral host computer223 to determine whether or not any two of the rubbed-off spots has the same symbol (e.g., all $10, all $20, etc.). Thecentral host computer223 then transmits a signal to theelectronic verification machine108 indicating whether or not theticket422 is a winner, and if so, the redemption value of theticket422. It should be noted that the functions of thecentral computer223 and its associated redemption file as described above can be preformed by the computer in theprocessor board220 of theelectronic verification machine108.
• As an alternative more than 2 bits can be used to represent each play spot. This will permit more or even all of the play spot areas to be validated by the[0270]electronic verification machine108. This embodiment reduces or eliminates calls to thecentral host computer223. However, this embodiment requires a longer play spot code and, hence, alonger bar code428 if all the other fields in the bar code are kept at the same size as in the previous embodiment. As indicated above, the size of thebar code80 can be reduced if a play spot code having a base larger than10 is used.
• A second approach to ticket validation involves using a validation file in the[0271]central computer223 rather than encoding play indicia value data in thebar code428 on thelottery ticket422. In this embodiment, the validation number only contains information related to the identity of the ticket, for example, the game number, pack number and ticket number. The validation number is read by theelectronic verification machine108 when, for example, the lottery agent inputs the validation number via thekeyboard178 of theelectronic verification machine108. Alternatively, the validation number and game number can be stored on the ticket in a machine-readable format, for example, as part of thebar code428 or even as a magnetic stripe. After theelectronic verification machine108 determines which play spot areas have been removed, theelectronic verification machine108 transmits the data as to which play spot areas have been removed along with the validation number to thecentral computer223. Thecentral computer223 contains the redemption or validation file which includes information corresponding to the ticket identification information for each ticket as well as a record with play indicia value data corresponding to each of theplay spot areas424A-P on eachticket422. Thecentral computer223 then uses the ticket identification information to read the record corresponding to theticket422 and obtains the play indicia value data corresponding to theplay spot areas424A-P that have been removed. If the number of the rubbed-off play spot areas424-P specified in therules432, contain the same symbol, the ticket is a winner. Thecentral computer223 then determines the redemption value corresponding to the matching play indicia value data and sends authorization to theelectronic verification machine108 so that the redemption value can be paid. An additional advantage of this approach is that after a ticket has been presented for redemption, the records within the validation file which correspond to the ticket can be updated to reflect that the ticket has been verified by theelectronic verification machine108 and thecentral computer223. Consequently, theticket422 can be presented for redemption only one time and thereafter the validation file contains information indicating that the ticket has been previously paid.
• VI. Stigmatization[0272]
• There are cases where it is desirable to provide a positive indication that a document such as the[0273]lottery ticket50 has been verified or validated by theelectronic verification machine108. This process is termed stigmatization. One approach as described above in Section V. is to register eachticket50 or document in a central computer that is connected to the electronic verification machine. Another approach is to stigmatize theticket50 or document itself.
• Providing a hole puncher in the[0274]electronic verification machine108 is one way to accomplish this object. In this case a hole is punched though a critical portion of the partial printed circuit after the verification process has taken place.
• Printing a cancellation or void indication on the document by means of a printer such as a dot matrix printer (not shown) located in the[0275]electronic verifications machine108 after verification is another approach that can be used.
• Fuses located in the circuits printed on the document can be used to stigmatize or void the document. Here sufficient power is applied to the document such as the[0276]lottery ticket50 by theelectronic verification machine108 to break for example one or more of the resistors82-94 or blow selected fuses printed on the document. It should be noted that fuses of this nature can also be used to store specified information in the document. For example, if an array of fuses is printed on the document, information can be stored on the document by having theelectronic verification machine108 selectively burn certain fuses much as a PROM is programmed. This technique has applications other than lottery tickets such as an alternative to magnetic stripes on credit cards. Information burned in by blowing fuses can be far more difficult to alter than information contained in a magnetic stripe.
• Coloration can also be used to stigmatize the document. In this case the document such as the[0277]lottery ticket50 would also be printed with temperature sensitive ink. Power applied to the document by theelectronic verification machine108 would generate sufficient heat in the circuits printed on the document to change the color of at least a portion of the document.
• VII. A Second Electronic Verification Machine and Verification Methods[0278]
• FIGS. 38 and 39 illustrate a second embodiment of the invention, which is a second[0279]electronic verification machine500. The basic components of theelectronic verification machine500 are shown in block diagram form in FIG. 40. Included in theelectronic verification machine500 is asensor array502 which is connected to adigital processor board504 by a set ofsensor plate lines506 and anexcitation line508. A set of lines510-514 provides signal inputs and outputs to amicrocontroller516 which forms part of thedigital processor board504. Asuitable microcontroller516 is the Motorola MC68HC711E9CFN2 that includes a multiplexed 8 bit analog to digital converter (“A/D”)517. Theelectronic verification machine500 also includes abar code reader518, astepper motor mechanism520 and a set of threedocument position sensors522 which are connected to thedigital processor board504 by a set of lines524-528. In the embodiment of the invention shown in FIG. 38, thedigital processor board504 is connected by a RS-232C serialdigital interface530 to a commercially available, microprocessor based, lotteryretail terminal532 that includes arandom access memory534. A set ofindicator lights535 that in this embodiment include “power on,” “ready” and “jammed ticket” also form a part of theelectronic verification machine500.
• FIG. 39 is a sectioned side view of the[0280]electronic verification machine500 which is primarily provided to illustrate a document interface and transport mechanism, indicated generally by536. Secured to ahousing538 is an upperdocument guide plate540 and a lowerdocument guide plate542 that combine to form achannel544 through which a document, such as a lottery ticket, can pass. The document (not shown) is placed in theupper opening546 of the channel and drops down in response to gravity until it makes contact with a first set ofpinch rollers548 and550 that extend through anaperture552 and anaperture554 inguide plates540 and542 respectively. Also included in theelectronic verification machine500 is a second set ofpinch rollers556 and558 that extend through anaperture560 and anaperture562 inguide plates540 and542 respectively; apressure roller564 which extends through anaperture566 in thelower guide plate542; a set of threedocument edge detectors568,570 and572 that are represented in FIG. 38 as thedocument position sensors522; and thebar code reader518 which is mounted in anaperture574 of thelower guide plate542. Amirror575 is mounted over theaperture574 which makes it possible for thebar code reader518 to read bar codes on either or both sides of the document as indicated by a dashed line577. In addition, thesensor array502 is mounted on theupper guide plate540 opposite thepressure roller aperture566. Thepinch rollers550 and558 along with thepressure roller564 are connected to thestepper motor520 by a toothed belt (not shown) so that therollers550,558 and564 will all rotate at the same rate.
• In operation, the document (not shown) is placed in the[0281]upper opening546 of the channel and drops down in response to gravity until it makes contact with the first set ofpinch rollers548 and550 which are normally not rotating. Meanwhile, thefirst edge detector568 will provide an indication to themicrocontroller516 that a document is present in the channel formed by theguide plates540 and542 causing thestepper motor520, in response to a first pulse rate applied to thestepper motor520 by themicrocontroller516, to rotate at a first rate. When the document has been detected by thesecond edge detector570 as emerging from thepinch rollers550 and548, themicrocontroller516 will increase the rate of rotation of thestepper motor520 resulting in the document being transported by therollers550,564 and558 at a rate of approximately 8 inches per second past thesensor array502. Thesecond edge detector570 also provides themircrocontroller516 with the precise location of the document so that themicrocontroller516 can initiate scanning of the document. Thepinch rollers548,550,556 and558 are composed of a conventional elastomeric material and thepressure roller564 is preferably composed of a closed cell polyurethane material in order to prevent this roller from absorbing or retaining any moisture that might be on the document. The purpose of thepressure roller564 is to insure contact between the document and thesensor array502. After passing thesensor array502, the document will pass thebar code reader518, which will transmit the bar code information on the document to themicrocontroller516, and theedge detector572 will provide an indication to themicrocontroller516 that the document has exited theelectronic verification machine500.
• It should be noted that the configuration of the[0282]electronic verification machine500 shown in FIG. 39 has a number of significant advantages including: a straight document path that minimizes the possibility of paper jams; positive control of the document by thestepper motor520 in conjunction with thepinch rollers550 and558; the use of thepressure roller564 to maintain contact of the document with thesensor array502; and the use of the edge detectors568-572 to provide themicrocontroller516 with information as to the location of the document in the electronic verificationmachine transport mechanism536. In addition, a self cleaning effect occurs because the document is in moving contact with thesensor array502 and further more, theelectronic verification machine500 can readily accept documents of varying thickness.
• FIG. 40 is a block diagram illustrating in more detail portions of the preferred embodiment of the[0283]sensor array502, thedigital processor board504 and themicrocontroller516 of FIG. 38. In this embodiment of the invention, the sensor array includes14 sensor plates, designated byreference numeral574, and arectangular excitation plate576 mounted on a printedcircuit board578. A set of 14 operational amplifiers, designated byreference numeral580, have their inverting inputs connected by thelines506 to each one of thesensor plates574. Also connected to the inverting inputs and the outputs of theoperational amplifiers580 is a feedback line, indicated byreference numeral582, that includes a feedback resistor R_f. The noninverting inputs of theoperational amplifiers580 are connected to ground as shown bylines584. The outputs of each of theoperational amplifiers580 are connected to one of twomultiplexers586 or588 that in turn are connected by a pair oflines590 and592 to a pair ofprecision rectifiers594 and596. Therectifiers594 and596 are connected to the analog to thedigital input517 of themicrocontroller516 via thelines510 and512. Control is provided to themultiplexers586 and588 from themicrocontroller516 by theline514. In addition, the circuit of FIG. 40 includes a trianglewave voltage generator598 that applies an AC excitation voltage over theline508 to theexcitation plate576. Thevoltage generator598 can be controlled, in this case switched on or off, by themicrocontroller516 over aline600. For illustrative purposes, FIG. 40 also includes within a dashedline602 an equivalent circuit of a document under test where C_t1represents the capacitance between theexcitation plate576 and the document; R_trepresents the resistance in the document between the excitation plate :576 and thefirst sensor plate574; and C_t2represents the capacitance between the document and thefirst sensor plate574.
• One of the objects of the circuit shown in FIG. 40 is to scan the document under[0284]test602, such as a lottery ticket, for conductive material. Because the frequency and amplitude of the voltage generated by the triangularwaveform voltage generator598 are constant, the current I on thesensor plate574 will be a square wave due to the relation I=C_totaldv/dt where C_totalis the combined capacitances of C_t1and C_t2. As a result the voltage drop across the feedback resistor R_fwill be a square wave having its amplitude proportional to the capacitance C_total. The preferred frequency of the voltage generator is between 20 KHz and 150 KHz. Thus, the voltage output onlines582 of theoperational amplifiers580 can be used to determine both the value of the coupling capacitance C_totaland if there is conductive material between each of thesensor plates574 and theexcitation plate576. By using twomultiplexers586 and588 and therectifiers510 and512, themicrocontroller516 can, in effect, sample the current on each of thesensor plates574, which would result from conductive material on thedocument602, thereby providing an indication of the presence or absence of conductive material across thedocument602. Thestepper motor520 of theelectronic verification machine500 advances thedocument602 in discrete steps of approximately between 0.02 inches and 0.03 inches past thesensor array502 and themicrocontroller516 applies the excitation signal to theexcitation plate576 for each step. In this manner themicrocontroller516 can be programmed to scan a predetermined portion or even thewhole document602 for conductive material as well as the values of the coupling capacitance C_total.
• Another very important capability of the circuit shown in FIG. 40, in addition to the determination of the presence of conductive material on the document under test, is that it can be used to determine an electrical signature of the document. For example, the electrical signature representing an electrical characteristic such as resistance can be measured as is discussed in more detail in connection with the circuits of FIGS. 18 and 41. Also, a measure of the total coupling capacitance C[0285]_totalcan be used as an electrical signature. As indicated above, if thevoltage generator598 generates a constant frequency triangular wave form, the current I on thesensor plate574 will be linearly related to the capacitance C_totaland therefore the coupling capacitance C_totalitself can be measured. The total capacitance C_totaldepends on the characteristics of the document under test, such as the dielectric constant K of a dielectric material covering the conductive material or the thickness t of the dielectric material, while other factors including the size of theexcitation plate576 and thesensor plates574 remain essentially constant. As a result, the value of the current I or changes in the current I can be used to measure a capacitive electrical signature of the document. For example, it would be possible in some cases to use a capacitive electrical signature to determine if a scratch-off coating covering conductive material on a lottery ticket has been removed.
• In the embodiment of the sensor array shown in FIG. 40, the 14[0286]sensor plates574 are square with each side 0.10 inches in length and the excitation plate is 0.10 inches in width. Theexcitation plate576 extends parallel to the linear array ofsensor plates574 and is located about 0.050 inches from thesensor plates574. Improved control of capacitance coupling is provided for by utilizing thepressure roller564 of FIG. 39 to maintain thedocument602 in direct physical contact with thesensor array502. Also, to insure adequate values of capacitance between thedocument602 and theplates574 and576, as represented by the capacitors C_t1and C_t2, the metal sensor andexcitation plates574 and576 are coated with a material having a dielectric constant greater than 5. A suitable material for this coating is Kapton. In the event that a document interface is used where the document is not in contact with the sensor or excitation plates, is preferable that an air gap of less than 0.004 inches be maintained between the document and the plates. Also, in order to assure adequate values of sensed capacitance, it is preferable to have therectangular excitation plate576 several times larger in area than thesensor plates574.
• It should be noted that one of the advantages of the verification or validation method described above, is that the ticket or document can be printed on a flexible substrate such as paper and because the conductive material can be in direct contact with the[0287]sensor array502, it is not necessary to apply a dielectric material over the document.
• Illustrated in FIG. 41 is an alternate embodiment of a sensor circuit of the type shown in FIG. 18 that can be used to make measurements of the electrical signatures, such as resistance, of conductive material on documents. The circuit of FIG. 41 is suitable for use with the mechanical arrangement of the[0288]electronic verification machine500 shown in FIG. 39 and is generally equivalent in function to thesensor array502 and theprocessor circuits504 shown in FIGS. 38 and 40. For purposes of explanation, the circuit diagram of FIG. 41 includes the document under testequivalent circuit602 which has been described in connection with FIG. 40 and the equivalent elements from FIGS. 18, 38 and40 carry the same reference numbers. As with the circuit of FIG. 18, aninductor604, for example having an inductance of 100 mH, is connected to each of a set of 5sensor plates606 in order to compensate, in phase, for the reactance resulting from the capacitance between thedocument602 and thesensor plates606 and a corresponding set ofexcitation plates608. Themicrocontroller516 can be programmed to perform the same frequency sweeping functions as themircrocontroller224 described in connection with FIG. 18 and theprocessor circuits504 can contain functional elements equivalent to the integrator (peak detector)238, the D/A converter240 and theVCO242. Included in this circuit is a set of 5excitation plates608. Although not shown in the schematic diagram of FIG. 41, theexcitation plates608 can be located between and aligned in a linear array with thesensor plates606. Although asingle excitation plate576 of the type shown in FIG. 40 can be used instead of theseparate excitation plates608, the use ofseparate excitation plates608 in this embodiment of the invention has the advantage of reducing distributed capacitances. Connected to each of theexcitation plates608 by aline609 is a triangular wave voltage controlled oscillator (VCO)610 in order to apply a triangularly shaped, AC excitation voltage or signal to the document under test. However, it should be noted that optimal performance of a resonant circuit can be achieved with a sinusoidal wave form instead of the triangular wave voltage generated by the generally less expensive VCO610. Also included in this circuit is a set of 5operational amplifiers612 connected in a voltage follower arrangement with thesensor plates606. Specifically, the noninverting inputs of each of theoperational amplifiers612 are connected, in this case, through theinductors604 to thesensor plates606 and to aresistor614 that in turn is connected to ground. As a result, the output of each of theoperational amplifiers612, on a set oflines616 which are also connected to the inverting input of theoperational amplifiers612, will be a voltage that represents the current flow through the resistor or resistance R_tof thedocument602 resulting from the excitation signal online609.
• As indicated above, the circuit of FIG. 41 can use a control circuit[0289]618, which can include a microcontroller such as themicrocontroller516, to perform an iterative resonance seeking algorithm to vary the frequency of the VCO610 until the resonance of the LC circuit including theinductor604 and the capacitance betweenplates606 and608 is found. The resulting voltage onlines616, which can be multiplexed, peak-detected and applied to the analog todigital input517 of themicrocontroller516 in a manner similar to that shown in FIG. 40, represents the value of the resistance of a conductive material on a document. In this way it is possible to determine the electrical signature, for example the value of resistance, of conductive material located in a predetermined position on a document. Since it is possible to make accurate measurements of electrical signatures using the circuit of FIG. 41, this approach can be particularly useful for those documents, such as a lottery probability ticket of the type shown at50 in FIG. 1, where particular accuracy may be important. Also, once the control circuit618 has determined the resonance frequency, it can use a standard resonance frequency equation, such as C=25,330/f²L, to determine the coupling capacitance to the document since the inductance of theinductor604 is known.
• Another embodiment of a sensor array is illustrated in FIG. 42 where a[0290]document620, such as a lottery ticket, is inserted between an upper array ofsensor plates622 and a lower array ofexcitation plates624. This arrangement has the advantage of reducing the sensitivity of the system to displacement of thedocument620 in a direction perpendicular to the plane of thedocument620.
• As illustrated in FIGS.[0291]43-45, one of the advantages of the systems shown in FIGS.38-40 is that it is possible to determine the location as well as the shape of conductive material on a document. As an example of how shapes on a document can be determined, a conventionalinstant lottery ticket626 having a scratch-off coating628, shown partially broken away, covering a set ofplay indicia630 is illustrated in FIG. 43. In this case the scratch-off coating includes a conductive material and one object of the system in this example is to determine what portion of the scratch-off coating has been removed as part of a ticket validating process. Contained in theterminal memory534, shown in FIG. 38, is agame signature map632 in which a bit map or digital representation of the shape of the scratch-off coating628 of theticket626 is stored. As previously described in connection with FIGS.38-40, theelectronic verification machine500 scans theticket626 for conductive material and themicrocontroller616 then transmits a digital representation of the location of the conductive material detected on theticket626 to a scanned data map contained in thememory534. At this point a microprocessor (not shown) in thelottery terminal532 can compare the contents of the scanneddata map634 to the game signature map and if the data in the scanned data map meets certain predetermined criteria such as location, shape or percentage of expected removal of the scratch-off coating628, then a comparison signal is generated indicating that theticket626 has passed a verification or validation test. One method for representing verification criteria is by a vector. In the case of theticket626, such a vector might have several bytes representing the starting address and the ending address of thegame signature map632 corresponding to where the scratch-off coating628 can be expected along with another byte having a value that represents the minimum percentage of the scratch-off coating that constitutes an acceptably played ticket. As a practical matter, players often only scratch off a portion of the lottery ticket's scratch-off coating, so that, for example, an acceptable percentage for a particular type of played ticket might be 30%. Use of vectors of this type makes it especially easy to reprogram the terminal532 for different types of lottery tickets or documents.
• Another method of verifying a document such as a lottery ticket of the scratch-[0292]off type626 is to utilize the capacitive signature of theticket626 as measured by theelectronic verification machine500. Taking, for example, theticket626 which can include a uniform conductive material (not shown) applied beneath the scratch-off coating628 and that is removable with thecoating628 of the type as described in U.S. Pat. No. 5,346,258, a measure of the signal to noise ratio between areas of theticket626 having the scratch-off coating628 and the areas that do not, can provide a strong indication of validity. This method starts by determining a value for the coupling capacitance C_totalfor each location on theticket626 by measuring the current I on thesensor plates574 using the circuit of FIG. 40. Then by taking the mean average T_sof the value of the coupling capacitance of the areas of theticket626 having the scratch-off coating628 along with the mean average T_pof the other areas and dividing T_sby T_p, a signal to noise ratio can be obtained. Here, T_srepresents the signal and T_prepresents the noise. Preferably, the value of T_sis calculated from only those coupling capacitance values that exceed a predetermined value such as 11 out of a maximum sensed value of 36. Computing this signal to noise ratio for an entire document such as theticket626 can provide an excellent indication of the validity of the document. It has been found, for instance, that lottery tickets of thetype626 will consistently produce signal to noise ratios of between 3.6 and 4.9.
• One of the reasons that the above described signal to noise ratios can provide such an excellent indication of validity is that it measures an inherent electrical signature of a document that can be very difficult to forge. In the example above, the measured coupling capacitance C[0293]_totalof the scratch-offareas628 of theticket626 are a function of two independent factors: the thickness t and the dielectric constant K of the scratch-off coating628. Because C_totalis equal to Kε₀A/t where ε₀is the permittivity of free space and A is the area of thecapacitor plate574, a forger would have to almost exactly match both the thickness t and the dielectric constant K of the scratch-off coating.
• In addition to lottery tickets, the scanning method as described above can be useful in the verification of a wide variety of documents. For instance, currency bills can be printed with conductive fibers or conductive inks located in predetermined locations. The[0294]electronic verification machine500 can then be used to verify the authenticity of the bills by determining electrical signatures as well as the location or the amount of conductive material in the bills. Since theelectronic verification machine500 of FIGS.38-40 can operate at relatively high speed, 8 to 10 inches per second, the verification of documents can be accomplished quickly and inexpensively.
• Another application for the[0295]electronic verification machine500 is in the validation of a pull-tabtype lottery ticket636 as shown in FIG. 46. The pull-tab ticket636 is made up of asubstrate638 upon which play indicia, indicated by640, are printed. Laminated over thesubstrate638 is a pull-tab stock member642 having a number of perforated pull-tabs644 located such that they cover theplay indicia640. The underside or laminate surface of the pull-tab member642 is printed with a layer of conductive ink, as indicated byreference numeral646, which forms a conductive plane and is not obvious to a player. In this type ofticket636, the conductive plane formed by theconductive ink layer646 will be interrupted when a player removes one or more of the pull-tabs644.
• Referring to FIG. 47, a pull-[0296]tab signature map648 is graphically represented along side the pull-tab ticket636, with pull-tabs644 shown as removed. As shown in this figure, the “0” bits in thesignature map648 correspond to positions of the pull-tab644 on theticket638. The remaining bits in thesignature map648 are set to “1.” As a result, thesignature map648 provides a digital representation of the location of the pull-tabs644 along the center line of the pull-tab ticket636. Thesignature map644 can be stored in thememory534 of thelottery terminal532 or in the case where a simplified version of the type ofelectronic verification machine500 of FIG. 38 is to be used, thesignature map644 can be stored in themicrocontroller memory516 or its equivalent.
• A simplified[0297]sensor array650, which can be used in theelectronic verification machine500 to validate the pull-tab ticket636, is shown in FIG. 48 as positioned over the pull-tab ticket636. Thesensor array650 includes asensor plate652 located between a pair ofexcitation plates654 and656 such that thesensor plate652 is aligned with the center line of the pull-tab ticket636. The circuits (not shown) connected to the sensor andexcitation plates652 and654 are substantially the same and operate in the same manner as the circuits in FIG. 40. In validating the pull-tab ticket636, theticket636 is scanned along its center line, in the direction indicated by anarrow656, by thesensor plate652 and its associated circuity in theelectronic verification machine500. If, for example, the output ofsensor plate652 is equivalent all “0”s, then theticket636 does not contain conductive ink and, as such, can be considered a forgery, perhaps a photocopy. Then by comparing thesensor plate652 output to thesignature map644 it is possible to determine how many, if any, of the pull-tabs644 have been opened.
• VIII. A Second Probability Game Ticket Configuration.[0298]
• FIGS.[0299]49-50 and52-72 show a second embodiment of aprobability game ticket700, which is the preferred embodiment to be used in conjunction with thesensor array502 of theelectronic verification machine500, shown in FIGS.38-40. FIG. 49 presents the finished appearance of theticket700. Theticket700 is printed on asubstrate702, such as card stock or paper, and has three portions: a display graphics portion, shown generally at704, a play field portion, shown generally at706, and a ticket identification portion, shown generally at708. As with theprevious ticket50, thedisplay graphics portion704 includes a variety of printed information such as thename710 of the game, rules712 for playing the game, and customizedart work714. Theplay field portion706 includes a group ofplay spot areas716A-H which are printed as overprint layers. Theplay field portion706 can also includeplay spot graphics718 which help to further visually delineate eachplay spot area716A-H. Eachplay spot area716A-H conceals a play indicia720A-H (shown in FIG. 61). For example, playspot area716A has been removed to reveal the underlying play indicia720A. Theticket identification portion708 includes a void-if-removedarea722 which is printed as an overprint layer. The void-if-removedarea722 can includeoverprint graphics724. The void-if-removedarea722 conceals a validation number726 (shown in FIG. 61) which contains information that can be used in validating theticket700. Theticket identification portion708 also includes aninventory control number728 and a machine-readable bar code730. Similar to thebar code80 of thefirst ticket50, thebar code730 can include information related to the validation number726 (shown in FIG. 61), to the pack and ticket numbers for theticket700 and to the redemption values of the play indicia720A-H. Thebar code730 thus serves as a ticket identification indicia for theticket700.
• FIG. 50 is a plan view of various circuit elements which are used in determining the authenticity and integrity of the[0300]ticket700. Theticket700 includes two general types of circuit elements which are used in association with the play indicia720A-H and with thebar code730. The first type of circuit element consists of individualindicia circuit elements732A-H which are used to determine the presence of the play indicia720A-H as well as the integrity of each of the underlying play indicia720A-H. Each of theindicia circuits732A-H includes a first capacitive pick-up area, generally denoted as734, a second capacitive pick-up area, generally denoted as736, and a resistive element, generally denoted as738, that is connected to and extends between the first and second capacitive pick-upareas734 and736. Thus, for example, theindicia circuit element732A includes the first capacitive pick-uparea734A, the second capacitive pick-uparea736A and theresistive element738A. Similarly, theindicia circuit element732B includes the first capacitive pick-uparea734B, the second capacitive pick-uparea736B, and theresistive element738B. Theresistive elements738A-H are printed in a serpentine pattern so as to cover most of the play indicia720A-H. As explained in more detail with reference to FIGS.69-70, each of theindicia circuit elements732A-H is associated with one of the underlying play indicia720A-H. Thus, for example, theindicia circuit element732A is associated with the play indicia720A, shown in FIG. 49. The individualindicia circuit elements732A-H are printed on theticket700 so that at least a portion of eachindicia circuit732A-H overlies one of the individual play indicia720A-H. In the preferred embodiment, theresistive element738 of theindicia circuit elements732 are printed on theticket700 to overlie one of the play indicia720. Moreover, in the preferred embodiment the capacitive pick-upareas734 and736 of theindicia circuit elements732 are printed on theticket700 so that the capacitive pick-upareas734 and736 do not overlie any of the play indicia720. Thus, for example, theresistive element738A of theindicia circuit element732A is printed in theticket700 to overlie the play indicia720A and while the capacitive pick-upareas734A and736A of theindicia circuit element732A are printed on theticket700 so that the capacitive pick-upareas734A and736A are spaced-apart from the play indicia720A and do not overlie the play indicia720A or any of the other play indicia720B-H.
• The individual[0301]indicia circuit elements732A-H capacitively couple with thesensor array502 of theelectronic verification machine500 when theticket700 is placed in theopening546 of theelectronic verification machine500 and is moved through the electronic verification machine by thestepper motor520, thepinch rollers548,550,556,558, and thepressure roller564, as described with reference to FIGS.38-40. Specifically, the first capacitive pick-upareas734A-H capacitively couple with thesensor plates574 of thesensor array502 and therefore serve as sensor capacitive pick-up areas for theindicia circuit elements732A-H. In addition, and the second capacitive pick-upareas736A-H capacitively couple with theexcitation plate576 of thesensor array502 and therefore serve as excitation capacitive pick-up areas for theindicia circuit elements732A-H. Consequently, the dimensions and positions of the capacitive pick-upareas734A-H and736A-H are determined by the dimensions and positions of theexcitation plate576 and thesensor plates574 of thesensor array502. In the preferred embodiment, the width of both the first and second capacitive pick-upareas734A-H and736A-H is on the order of 0.26 inches, the height of the first capacitive pick-upareas734A-H is about 0.05 inches, and the height of the second capacitive pick-upareas736A-H is on the order of 0.10 inches. In addition, the first capacitive pick-upareas734A-H are longitudinally spaced-apart from the second capacitive pick-upareas736A-H by a predetermined distance which, in the preferred embodiment is about 0.07 inches. Moreover, each of the individual indicia circuit elements, for example,indicia circuit element734B, is longitudinally spaced apart from adjacent indicia circuit elements, for example,indicia circuit elements732A and732C, by a predetermined distance. The configuration of theindicia circuit elements732A-H offer several advantages. First, the individualindicia circuit elements732A-H provide discreet electrical signatures for each of theplay spot areas716A-H and associated underlying play indicia720A-H. Consequently, theindicia circuit elements732A-H can be used to determine the presence as well as the integrity of the individualplay spot areas716A-H and the associated underlying play indicia720A-H. In addition, each of theindicia circuit elements732A-H is spatially isolated from other circuit elements. Consequently, stray electrical noise is minimized or eliminated.
• As explained in more detail below, portions of the[0302]indicia circuit elements732A-H are removed when theplay spot areas716A-H are removed to reveal the play indicia720A-H. Consequently, the ink used to print theindicia circuit elements732A-H should have a reduced adhesiveness so that the portions of theindicia circuit elements732A-H are readily removed from theticket700. In addition, the ink used to print theindicia circuit elements732A-H should also be fairly conductive. In the presently preferred embodiment of the invention, the sheet resistivity of the ink used to print theindicia circuit elements732A-732H is on the order of 2 KΩ/□. Table 4 describes the presently preferred formulation for the ink used print theindicia circuit elements732A-732H.

  TABLE 4
  Ink Formulation For TheIndicia Circuit Elements 732A-732H

  	material	wt %

  	Polyamide resin	1.75
  	Dimethylethanol amine	0.25
  	Ammonium Hydroxide	0.25
  	Conductive Carbon Black	13.00
  	Polyethylene/PTFE wax	1.50
  	Silicone paste	1.25
  	Acrylic synthetic pigment	4.00
  	Colloidal acrylic	9.00
  	Ethyl Alcohol	2.00
  	Styrenated acrylic emulsion (high Tg)	8.25
  	Styrenated acrylic emulsion (low Tg)	16.45
  	Silicone-based surfactant	0.50
  	Water	41.80

• An alternative ink formulation for the ink used to print the[0303]indicia circuit elements732A-732H is given in Table 5. This ink has a lower sheet resistivity than that of the ink described in Table 4, on the order of about 1 KΩ/□.

  TABLE 5
  Alternative Ink Formulation For TheIndicia Circuit Elements
  732A-H

  	material	wt %

  	water	41.8
  	Dispersant (W-22)	4.8
  	Dimethylethanolamine	0.25
  	Defoamer (RS-576)	0.4
  	Carbon Black	15
  	wetting agent (BYK 348)	0.5
  	EVCL Emulsion Vancryl 600	3
  	Ammonium Hydroxide	0.25
  	DC-24Silicone Emulsion	2
  	Styrenated Acrylic Varnish (J678)	5
  	Plasticizer 141	2
  	Styrenated Acrylic Emulsion 7830	20
  	Ethanol	5

• The second general type of circuit element is an[0304]integrity circuit element740 that is used to determine the authenticity and integrity of the ticket identification indicia, such as thebar code730. Theintegrity circuit element740 includes a first capacitive pick-uparea742 that is shaped and sized to capacitively couple with one of thesensor plates574 of thesensor array502. Theintegrity circuit element740 also includes a second capacitive pick-uparea744 that is shaped and positioned to capacitively couple with theexcitation plate576 of thesensor array502. Both the first and second capacitive pick-upareas742 and744 are printed entirely within theticket identification portion708 of theticket700 and, as explained in more detail below, underlie at least a portion of the ticket identification indicia, such as thebar code730. Theticket integrity circuit740 also includes aresistive element746 that is connected to and extends between the first and second capacitive pick-upareas742 and744. Theresistive element746 is printed on theticket700 so that aportion748 of theresistive element746 is located within theplay field portion706 of theticket700 and is shown as encompassingindicia circuit elements732D and732H. Theintegrity circuit element740 provides a discreet electrical signature for the ticket identification indicia, such as thebar code730, and thus can be used to determine the authenticity and integrity of the ticket identification indicia. For example, if an attempt is made to replace thebar code730 by cutting theticket700, theresistive element746 would also be cut and thus detectable by theelectronic verification machine500.
• The[0305]ticket700 can include additional data circuits, generally denoted as750, which can be used to provide additional ticket authenticity and integrity information. The data circuits750 include first capacitive pick-up areas752 and second capacitive pick-up areas754 that are positioned and shaped to capacitively couple with one of thesensor plates574 and with theexcitation plate576, respectively, of thesensor array502. The data circuits750 also include data tracks756 that spans between the capacitive pick-up areas752 and754. The data tracks756 are used to electrically store data in a binary form. For example, when the data tracks756 include a conductive material the data tracks can encode a bit-on or “1” signal. Alternatively, when the data tracks756 do not include a conductive material the data tracks756 can encode a bit-off or “0” signal. As shown in FIG. 50, theticket700 preferably includes at least two data circuits,750A and750B, both of which are printed within theticket identification portion708. By including twodata circuits750A and750B, the ticket can store four separate binary codes, e.g., 11, 10, 01, and 00. As shown in FIG. 50, thedata track756A of thedata circuit750A does not include a conductive material and so encodes a bit-off or “0” signal while thedata track756B of thedata circuit750B includes conductive material and so encodes a bit-on or “1” signal. The binary code produced by thedata circuits750A and750B, when used in conjunction with additional information stored elsewhere on theticket700, for example, in thevalidation number726, can provide at least partial ticket authenticity and integrity information. The ink used to print theintegrity circuit element740 and thedata circuit elements750A-B should be fairly conductive. Table 11, in Section XII.B. (below) describes the presently preferred formulation for the ink used to print theintegrity circuit elements740. The ink described in Table 11 has a sheet resistivity of less than 5 KΩ/□. Table 1 presents an alternative ink formulation for printing the integrity circuit elements. The ink described in Table 1 has sheet resistivity of about 3 MΩ/□.
• It should be noted that the two general types of circuit elements, the[0306]indicia circuit elements732A-H and theintegrity circuit element740, are actually printed on theticket700 as separate layers. In addition, theticket700 includes several other layers that are used to generate the finished form of theticket700 shown in FIG. 49. FIGS.51-72 illustrate the sequence and configurations of the layers which form parts of theticket700. Theticket700 is preferably printed by an intaglio method. A gravure printing method is especially preferred as it allows for the widest range of ink and coating formulations, although other intaglio printing methods can be used. Theticket700 can also be printed by screen printing, relief printing, planographic printing, letterpress, and flexographic printing. However, as noted a gravure printing process is preferred for printing theticket700. FIG. 51 presents a schematic diagram of agravure printing press760 which is suitable for printing theticket700. Thepress760 has fifteen printing stations762-790, each of which prints one layer on theticket700, and oneink jet printer792 that prints the play indicia720A-H, thevalidation number726, theinventory control number728, and thebar code730. Thefirst print station762 prints afirst layer794 on theticket700. Thefirst layer794 is an opaque blocking layer that helps to protect the play indica720A-H and thecircuit elements732A-H,740,750A, and750B, from surreptitious detection by candling.
• In order that the circuit elements such as[0307]732A-H,740,750A or750B can be detected, the firstopaque blocking layer794, as well as any other layer on the ticket, should be relatively non-conductive as compared to the conductivity of thecircuit elements732A-H,740,750A or750B. Otherwise, thelayer794 would tend to interfere with the detection of the electrical signatures of thecircuit elements732A-H,740,750A or750B. This is especially the case with the capacitive pick-up areas such as734A-H and736A-H and in particular with respect to the capacitive pick-upareas734A-H that serve in this embodiment as sensor capacitive pick-up areas. It has been found that a relatively conductive layer under the capacitive pick-uparea734 can result in a noise spike, making it difficult for theelectronic verification machine500 to accurately the presence or signature of theresistive element738. Although it is possible to detect the presence of theresistive elements738A-H and746 using an electronic verification machine of the type shown at500 where the conductivity of the circuit elements such as732A-H,740,750A and750B is only twice the conductivity of an adjacent layer such as thelower blocking layer794, it is desirable that the difference in conductivity be at least one order of magnitude or 10 dB and more preferably, two to three orders of magnitude or 20 to 30 dB. Therefore, it is considered preferable that, in order to reduce the signal to noise ratio in scanning the circuit elements such as732A-H,740,750A and750B, that thelayer794 appear to be substantially nonconductive in comparison to thecircuit elements732A-H,740,750A and750B. By increasing the difference in conductivity between the circuit elements such as732A-H,740,750A and750B and thelayer794 it is possible to reduce the manufacturing tolerances of both theelectronic verification machine500 and theticket700. This consideration is significant when documents and verification machines are being produce in large volumes. In particular where thelottery tickets700 are printed in the millions and are subject to various types of abuse such as bending and crumpling, the difference in conductivity between thecircuit elements732A-H,740,750A and750B and thelayer794 is preferably three orders of magnitude or30 dB. Thus, in the preferred embodiments of theelectronic verification machine500 and theticket700, where theblocking layer794 is a continuous layer underlying all of thecircuit elements732A-H,740,750A and750B, the desired relationship between the sheet resistivity (ρs_(LBL)) of thelower blocking layer794 and the sheet resistivity (ρs_(CE)) of thecircuit elements732A-H,740,750A, and750B is at least two orders of magnitude as illustrated by the equation:
• ρs_(LBL)≧1000 ρs_(CE)
• FIG. 52 illustrates the preferred embodiment of the[0308]lower blocking layer794 when thelower blocking layer794 has a sheet resistivity that is at least one thousand times greater than the sheet resistivities of thecircuit elements732A-H,740,750A, and750B. In this embodiment, thelower blocking layer794 is printed as a continuous, substantiallyopaque layer796 that completely overlies theplay field portion706 and theticket identification portion708 of theticket700. Thelower blocking layer794 can, however, be printed with materials that have a lesser difference in conductivity relative to thecircuit elements732A-H,740,750A, and750B as long as the configuration of thelower blocking layer794 electrically isolates at least portions of thecircuit elements732A-H,740,750A, and750B from thelower blocking layer794. For example, FIG. 53 illustrates an alternative configuration of thelower blocking layer794 which is printed as a barredlayer798 that includes laterally spaced-apartstrips800A and800B which are printed with a material which is minimally conductive relative to the material used to print thecircuit elements732A-H,740,750A, and750B. The spaced-apartstrips800A and800B are substantially opaque and longitudinally span theplay field portion706 and theticket identification portion708 of theticket700. The spaced-apartstrips800A and800B definechannels802A and802B for theresistive elements738A-H of theindicia circuit elements732A-H. The space between thestrip800A and theinterface804 between theplay field portion706 and thedisplay portion704 and the space between thestrips800A and800B definechannels806A and806B for the capacitive pick-upareas734A-H and736A-H of theindicia circuit elements732A-H, for the capacitive pick-upareas742 and744 of theintegrity circuit element740, and for the capacitive pick-upareas752A-B and754A-B of thedata circuits750A-B. The configuration of thelower blocking layer794 thus electrically isolates the capacitive pick-upareas734A-H,736A-H,742,744,752A-B, and754A-B of thevarious circuit elements732A-H,740,750A, and750B from the minimallyconductive strips800A and800B. FIG. 54 illustrates another embodiment of thelower blocking layer794 which includes a patternedlayer808 that is printed with a material that is minimally conductive relative to thecircuit elements732A-H,740,750A, and750B. The patternedlayer808, which, is substantially opaque, spans both the play field andticket integrity portions706 and708 of theticket700 and definesseveral apertures810A-H,812,314A, and814B which electrically isolate portions of thecircuit elements732A-H,740,750A, and750B. Specifically, theapertures810A-H are positioned and shaped to electrically isolate the first capacitive pick-upareas734A-H of theindicia circuit elements732A-H, theaperture812 is positioned and shaped to electrically isolate the first capacitive pick-up742 of theticket integrity circuit740, and theapertures814A and814B are positioned and shaped to electrically isolate the first capacitive pick-upareas752A and752B of the data circuits670A-B. As previously noted, the first capacitive pick-upareas734A-H,742, and752A-B serve a sensor capacitive pick-up areas when theticket700 is read by theelectronic verification machine500. Table 10, in Section XII.B. (below) describes the presently preferred formulation for an ink used to print thelower blocking layer794. The ink described in Table 10 has a sheet resistivity which is greater than about 20 MΩ/□. An alternative formulation for the ink used to print thelower blocking layer794 is given in Table 6. The formulation in Table 6 is particularly useful for printing thelower blocking layer794 either as the barredlayer798 or as the patternedlayer808.

  TABLE 6
  Ink Formulation For TheLower Blocking Layer 794

  	Material	wt %
  	Predesol Carbon Black 1649V	25
  	(KVK USA, Inc.)
  	VCMA	10
  	methyl-ethyl ketone	65

• It should be noted that since one of the functions of the[0309]lower blocking layer794 is to obscure the play indicia720A-H and thecircuit elements732A-H,740, and750A-B, it is desirable that theblocking layer794 be a opaque as possible. One way to achieving a sufficiently opaque layer is to use inks that contain black pigments or other dark pigments in order to mask the circuitelements circuit elements732A-H,740, and750A-B. Thus, it is convenient to use carbon or carbon black in the ink used for thelayer794. Using carbon black normally will result in an ink with a sheet resistivity less than would be the case with a basically non-conductive material such as thepaper substrate702. However, the ink formulation presented in Table 6 above does provide a relatively high sheet resistivity which, in this case, is greater than 20 MΩ/□. Thus, as noted above, this ink formulation is suitable for printing thelower blocking layer794 provided at least portions of thecircuit elements732A-H,740,750A, and750B are electrically isolated from thelayer794, for example, by printing thelower blocking layer794 as the barredlayer798 having spaced-apart strips800A-B or by printing thelower blocking layer794 as the patternedlayer808 having theapertures810A-H,812,814A, and814B.
• The second[0310]printing press station764 prints thesecond layer826 which consists of theticket integrity circuit740 and thedata circuits750A-B. The appearance of theticket700 at this point depends on the form of thelower blocking layer794. FIG. 55 shows theticket700 when thelower blocking layer794 is printed as the continuous, substantiallynon-conductive layer796. Both of thedata circuits750A and750B are printed over thefirst layer796 within theticket identification portion708 of theticket700. The first capacitive pick-uparea742 and the second capacitive pick-uparea744 of theintegrity circuit element740 are also printed within theticket identification portion708 over thelayer796. Theresistive element746, which is connected to and extends between the capacitive pick-upareas742 and744 of theintegrity circuit element740, is printed on thelayer796 so that theportion748 of theresistive element746 is located within theplay field portion706 of theticket700. FIG. 56 shows theticket700 when thelower blocking layer794 is printed as the barredlayer798. The first capacitive pick-uparea742 of theintegrity circuit element740 is printed in theticket identification portion708 and is located within thechannel806A. The first capacitive pick-uparea742 thus is not printed over either of thestrips802A or802B and is actually printed on thesubstrate702 of theticket700. Similarly, the capacitive pick-upareas752A and754A of thedata circuit element750A and the capacitive pick-upareas752B and754B of thedata circuit element750B are printed in theticket identification portion708 and are located within thechannel806B. The capacitive pick-upareas752A,754A,752B, and754B of thedata circuit elements750A and750B are thus printed on thesubstrate702 of theticket700. Consequently, because the capacitive pick-upareas742,752A,754A,752B, and754B are printed on thesubstrate702, the capacitive pick-upareas742,752A,754A,752B, and754B are electrically isolated from thelayer798. The second capacitive pick-uparea744 is printed within theticket identification portion708 over thestrip800B and thus is located in thechannel802B. Theresistive element746, which is connected to and extends between the capacitive pick-upareas742 and744 of theintegrity circuit element740, is printed on theticket700 so that theportion748 of theresistive element746 is located within theplay field portion706 of theticket700. FIG. 57 shows theticket700 when thelower blocking layer794 is printed as the patternedlayer808. The first capacitive pick-uparea742 of theintegrity circuit element740 is printed in theticket identification portion708 and is located within theaperture812. The first capacitive pick-uparea742 thus is not printed over the patternedlayer808 and is actually printed on thesubstrate702 of theticket700. Similarly, the capacitive pick-uparea752A of thedata circuit element750A and the capacitive pick-uparea752B of thedata circuit element750B are printed in theticket identification portion708 and are located within theapertures814A and814B, respectively. The capacitive pick-upareas752A and752B of thedata circuit elements750A and750B are thus printed on thesubstrate702 of theticket700. Consequently, because the capacitive pick-upareas742,752A, and752B are printed on thesubstrate702, the capacitive pick-upareas742,752A, and752B are electrically isolated from thelayer808. The second capacitive pick-uparea744 of theintegrity circuit element740 and the second capacitive pick-upareas754A and754B of thedata circuits750A and750B are printed directly over the patternedlayer808, within theticket identification portion708 of theticket700. Theresistive element746, which is connected to and extends between the capacitive pick-upareas742 and744 of theintegrity circuit element740, is printed on theticket700 so that theportion748 of theresistive element746 is located within theplay field portion706 of theticket700.
• The third[0311]printing press station766 prints the third layer818 (shown in FIG. 58) which is a masking layer that masks thelower blocking layer794 and prevents visual interference from thelower blocking layer794 when a user inspects the play indicia720A-H (shown in FIG. 61). As shown in FIG. 58 themasking layer818 is printed as a continuous layer that covers both theplay field portion706 and theticket identification portion708 of theticket700. In order not to interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B, the electrical conductivity of themasking layer818 should be significantly less than the electrical conductivity of thecircuit elements732A-H,740,750A, and750B. In the preferred embodiment, the sheet resistivity of themasking layer818 is greater than 10⁸Ω/□. A suitable formulation for themasking layer818 is given in Table 7.

  TABLE 7
  Ink Formulation For TheMasking Layer 818

  	material	wt %

  	Predasol rutile white 1300-PA	33.33
  	versamide 940 resin	22.22
  	ethanol	22.225
  	heptane	22.225

• The[0312]fourth printing station768 prints thefourth layer820 which is a primer layer that provides a suitable surface for printing the play indicia720A-H (shown in FIG. 61). As shown in FIG. 59, theprimer layer820 is printed as a continuous layer that covers both theplay field portion706 and theticket integrity portion798 of theticket700. In order not to interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B, the electrical conductivity of theprimer layer820 should be significantly less than the electrical conductivity of thecircuit elements732A-H,740,750A, and750B. In the preferred embodiment, the sheet resistivity of theprimer layer820 is greater than 10⁸Ω/□. Printing stations770-774 provide the features printed in thedisplay portion704 of theticket700 which, as shown in FIG. 60, include the name of thegame710, the rules for playing thegame712, and the customizedart work714. Theink jet station792 prints the play indicia720A-H, thevalidation number726, theinventory control number728 and thebar code730. As shown in FIG. 61 the play indicia720A-H are printed directly on theprimer layer820 within theplay field portion706 of theticket700. Thevalidation number726, theinventory control number728 and thebar code730 are also printed directly on theprimer layer820 but are located within theticket identification portion708 of the ticket.Station776 prints the back822 of theticket700 which, as shown in FIG. 62, can includeadditional information824 concerning the game.
• [0313]Station778 prints thefifth layer826 which is a seal coat layer that protects the play indicia720A-H and thevalidation number726 against abrasion. FIG. 63 illustrates theseal coat layer826 which is printed on theticket700 so that thelayer826 covers all of theprimer layer820 within theplay field portion706 and so that theseal coat layer826 covers thevalidation number726 within theticket identification portion708 of the ticket. In order not to interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B, the electrical conductivity of theseal coat layer826 should be significantly less that the electrical conductivity of thecircuit elements732A-H,740,750A, and750B. In the preferred embodiment, the sheet resistivity of theseal coat layer826 is greater than 10⁸Ω/□. A suitable formulation for theseal coat layer826 is given in Walton, U.S. Pat. No. 4,726,608.
• The next layer is a release coat layer, generally denoted as[0314]828, that is printed by thestation780. Therelease coat layer828 is not continuous but instead in this embodiment consists ofdiscreet layer portions828A-828H that are associated with the play indicia720A and a discrete layer portion828I that is associated with thevalidation number726. Thus, as shown in FIG. 64, therelease coat layer828 is printed on theseal coat layer826 so that the releasecoat layer portion828A covers the play indicia720A. Similarly, the releasecoat layer portion828C covers the play indicia720C and the releasecoat layer portion828F covers the play indicia720F. In addition, the release coat layer portion828I covers thevalidation number726. Therelease coat828 serves two general functions. First, therelease coat828 assures that layers which overlie the play indicia720A-H and thevalidation number726 can be removed to reveal the play indicia720A-H and thevalidation number726. In addition, as explained with reference to FIG. 75, the discreterelease coat portions828A-H help to ensure that the electrical signatures of theindicia circuit elements732A-H change when the layers overlying the play indicia720A-H are removed to reveal the play indicia720A-H. In order not to interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B, the electrical characteristics of therelease coat layer828 should be significantly less than the electrical conductivity of thecircuit elements732A-H,740,750A, and750B. In the preferred embodiment, the sheet resistivity of therelease coat layer828 is greater than 10⁸Ω/□. However, since therelease coat layer828 does not contact any of the capacitive pick-upareas734A-H.736A-H,742A-H,744A-H,752A-B, and754A-B, a lesser sheet resistivity, for example about 10⁷Ω/□, would be acceptable. A suitable formulation for therelease coat layer828 is given in Walton, U.S. Pat. No. 4,726,608.
• [0315]Station782 prints the next layer which is an opaqueupper blocking layer830 that helps to protect the play indicia720A-H, thevalidations number726 and portions of thecircuit elements732A-H,740,750A, and750B against surreptitious detection by candling. The preferred embodiment of theupper blocking layer830 has a sheet resistivity that is at least about 1000 times greater than the sheet resistivity of thecircuit elements732A-H,740,750A, and750B. Consequently, in the preferred embodiment theupper blocking layer830 does not interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B and there is no need to electrically isolate thecircuit elements732A-H,740,750A, and750B from theupper blocking layer830. Thus, shown in FIG. 65, in the preferred embodiment theupper blocking layer830 is printed as acontinuous layer832 that overlies theplay field portion706 of theticket700 and overlies thevalidation number726 within the ticket integrity portion of theticket700. The play indicia720A and the associatedrelease coat portion828A are shown in phantom for reference. A presently preferred formulation for the ink used to print theupper blocking layer830 is given in Table 8. The ink formulation described in Table 8 has a sheet resistivity greater than 1 GΩ/□.

  TABLE 8
  Ink Formulation For TheUpper Blocking Layer 830

  	Material	wt %

  	non-conductive carbon black dispersion (35% carbon)	23.71
  	Normal propyl acetate	21.85
  	Heptane	25.94
  	Rubber block copolymer	6.25
  	Calcium carbonate	8.00
  	Maleic rosin ester resin	1.50
  	Titanium dioxide	7.00
  	Silicone paste	1.50
  	Diacetone alcohol	0.50
  	Terpene phenolic resin	0.75
  	PE/PTFE wax blend	3.00

• The[0316]upper blocking layer830 can also be printed with materials that have a lesser difference in conductivity relative to thecircuit elements732A-H,740,750A, and750B as long as the configuration of thelayer830 electrically isolates at least portions of theindicia circuit elements732A-H. Another suitable ink for theupper blocking layer830 is given in Table 9.

  TABLE 9
  Ink Formulation For TheUpper Blocking Layer 830

  	material	wt %

  	Heptane	34.1
  	Normal Propyl Acetate	30
  	Rosin Ester Resin 3330	10.2
  	Silicone Dispersant BYK 163	0.7
  	Carbon Black 350	13
  	Rubber Copolymer D 1107	9.2
  	Calcium Carbonate	1.7
  	Polyethylene/PTFE wax blend	1

• Similar to the[0317]lower blocking layer794, one of the functions of theupper blocking layer830 is to obscure the play indicia720A-H and thecircuit elements732A-H. Consequently, theupper blocking layer830 should be as opaque as possible, a goal which is conveniently obtained by using carbon black or other dark pigments in the ink used to print theupper blocking layer830. However, the presence of carbon black in the ink used to print theupper blocking layer830 can result in an ink formulation that is somewhat conductive. However, the ink formulation in Table 9 does provide a relatively high sheet resistivity which, in this case, is greater than about 20 MΩ/□. In addition, the ink formulation in Table 9 has a reduced graphic adhesiveness compared the to the ink presented in Table 6 which is suitable for printing thelower blocking layer794. The ink presented in Table 9 therefore can be readily removed from theticket700 when theplay spot areas716A-H are removed to reveal the underlying play indicia720A-H.
• FIG. 66 illustrates an alternative configuration of the[0318]upper blocking layer830 which is a barredlayer834 that is printed with a material which is minimally conductive relative to the material used to print thecircuit elements732A-H,740,750A, and750B. The barredlayer834 includes laterally spaced-apartstrips836A and836B which are substantially opaque and longitudinally span theplay field portion706. Thestrips836A-B also cover thevalidation number726 within theticket identification portion708 of theticket700. The spaced-apartstrips836A and836B definechannels838A and838B for theresistive elements738A-H of theindicia circuit elements732A-H. Thechannels838A and838B contain the material used to print theupper blocking layer830. The space between thestrip836A and theinterface804 between theplay field portion706 and thedisplay portion704 and the space between thestrips836A and836B definechannels840A and840B for the capacitive pick-upareas734A-H and736A-H of theindicia circuit elements732A-H. The layer that is exposed by thechannels840A and840B is theseal coat layer826 which, as previously stated, has a sheet resistivity greater than 10⁸Ω/□. The configuration of the barredlayer834 thus electrically isolates the capacitive pick-upareas734A-H and736A-H of theindicia circuit elements732A-H from the minimallyconductive strips836A and836B. The barredlayer834 is the preferred form of theupper blocking layer830 when thelower blocking layer794 is printed as the barredlayer798 shown in FIG. 53. Theupper blocking layer830 is printed in registry with thelower blocking layer794 so that the spaced-apartstrips836A and836B of the upper barredlayer834 are aligned with the spaced-apartstrips800A and800B of the lower barredlayer798. Consequently, thechannels838A and838B and thechannels840A and840B which are defined by the upper barredlayer834 coincide with thechannels802A and802B and thechannels806A and806B, respectively, which are defined by the lower barredlayer798. In FIG. 66, the play indicia720A and the associatedrelease coat portion828A are shown in phantom for reference. The play indicia720A and the associatedrelease coat portion828A are printed on theticket700 so that the play indicia720A and the associatedrelease coat portion828A are aligned with both thestrip836A of theupper blocking layer830 and thestrip800A of thelower blocking layer794. The play indicia720A and the associatedrelease coat portion828A are thus within both thechannel838A defined by theupper blocking layer830 and thechannel802A defined by thelower blocking layer794.
• FIG. 67 illustrates another embodiment of the[0319]upper blocking layer830 which includes a patternedlayer842 that is printed with a material that is minimally conductive relative to thecircuit elements732A-H,740,750A, and750B. The patternedlayer842, which is substantially opaque, overlies the entireplay field portion706 of theticket700 and also covers thevalidation number726 within theticket identification portion708 of theticket700. The patternedlayer842 defines several apertures844-H which electrically isolate portions of theindicia circuit elements732A-H. Specifically, the apertures844-H are positioned and shaped to coincide with the first capacitive pick-upareas734A-H of theindicia circuit elements732A-H. The exposed layer within theapertures844A-H is theseal coat layer826 which has a sheet resistivity greater than 10⁸Ω/□. The patternedlayer842 is the preferred form of theupper blocking layer830 when thelower blocking layer794 is printed in the patternedlayer808 shown in FIG. 54. Theupper blocking layer830 is printed in registry with thelower blocking layer794 so that theapertures844A-H defined by the patternedlayer842 are aligned with theapertures810A-H defined by the lower patternedlayer808. Thus, for example, theaperture844A of theupper blocking layer830 coincides with theaperture810A of thelower blocking layer794. In FIG. 67, the play indicia720A and the associatedrelease coat portion828A are shown in phantom for reference. The play indicia720A and the associated releasecoat layer portion828A are printed on the ticket adjacent theaperture844A in theupper blocking layer830. Because theupper blocking layer830 is printed in registry with thelower blocking layer794, the play indicia720A and the associate releasecoat layer portion828A are also printed adjacent theaperture810A in thelower blocking layer794. A suitable ink for printing theupper blocking layer830 either as the barredlayer834 or as the patternedlayer842 was given previously in Table 9.
• The[0320]station784 prints the next layer which consists of theindicia circuit elements732A-H. The appearance of theticket700 at this point varies according to the configuration of theupper blocking layer830. FIG. 68 illustrates theticket700 when theupper blocking layer830 is printed as thecontinuous layer832. Since in the preferred embodiment thecontinuous layer832 is printed with a material that does not interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B there is no need to isolate any portions of theindicia circuit elements732A-H from theupper blocking layer830. Consequently, theindicia circuit elements732A-H are printed directly on thecontinuous layer832. Theindicia circuit elements732A-H are positioned to align with the play indicia720 so that theresistive elements738 overlie the play indicia720. Thus, for example, theindicia circuit element732A is printed on thelayer832 to align with the play indicia720A and the associated releasecoat layer portion828A (shown in phantom) so that theresistive element738A overlies the play indicia720A and the associated releasecoat layer portion828A.
• FIG. 69 illustrates the form of the[0321]ticket700 when theupper blocking layer830 is printed as the barredlayer834. In FIG. 69 the play indicia720A and the associated releasecoat layer portion828A are shown in phantom for reference. However it should be kept in mind that neither the play indicia720A and nor the associated releasecoat layer portion828 would be visible because of theupper blocking layer830. Theindicia circuit elements732A-H are printed on theticket700 so that the first capacitive pick-upareas734A-H and the second capacitive pick-upareas736A-H are printed in registry with thechannels840A and840B defined by the barredlayer834. For example, theindicia circuit element732A is printed on theticket700 so that the first and second capacitive pick-upareas734A and734B are positioned within thechannel840A. Similarly, theindicia circuit element732F is printed on theticket700 so that the first and second capacitive pick-upareas734F and736F are positioned within thechannel840B. As noted earlier, the layer exposed in thechannels840A and840B is theseal coat layer826 which has a sheet resistivity greater than about 10⁸Ω/□. Thechannels840A and840B defined by the barredlayer834 thus electrically isolate the first capacitive pick-upareas734A-H and the second capacitive pick-upareas736A-H of theindicia circuit elements732A-H from the minimallyconductive strips838A and838B. Moreover, theupper blocking layer830 is printed in registry with thelower blocking layer794 so that theupper channels840A and840B are aligned with thelower channels802A and802B. The first capacitive pick-upareas734A-H and the second capacitive pick-upareas736A-B of theindicia circuit elements732A-H therefore are electrically isolated from the minimallyconductive strips800A and800B in thelower blocking layer794.
• The[0322]indicia circuit elements732A-H are also printed on theticket700 so that theresistive elements738A-H are aligned with thestrips836A-B and overlie the play indicia720A-H. For example, theindicia circuit element732A is printed on theticket700 so that theresistive element738A is printed on thestrip836A, within thechannel838A, and overlies the play indicia720A and the associated releasecoat layer portion828A (shown in phantom). Similarly, theindicia circuit element732G is printed on theticket700 so that theresistive element738G is printed on thestrip836B, within thechannel838B, and overlies the play indicia720G (not shown) and the associated releasecoat layer portion828G (not shown). In addition, thestrips826A and836B of the upper barred blockinglayer834 are printed in registry with thestrips800A and800B of the lower barredblocking layer798. Consequently, the play indicia720A-H are intermediate thestrips836A-B and800A-B of the upper and lower barred blocking layers,834 and798 respectively, and so are protected against surreptitious detection by candling.
• FIG. 70 illustrates the form of the[0323]ticket700 when theupper blocking layer830 is printed as the patternedlayer842. The play indicia720A and the associated releasecoat layer portion828A are shown in phantom for reference. However it should be kept in mind that neither the play indicia720A and nor the associated releasecoat layer portion828 would be visible because of theupper blocking layer830. Theindicia circuit elements732A-H are printed on theticket700 so that the first capacitive pick-upareas734A-H are in registry with and positioned within theapertures844A-H defined by the upperpatterned blocking layer842. For example, the first capacitive pick-uparea734A of theindicia circuit element732A is in registry with and positioned within theaperture844A. Similarly, the first capacitive pick-uparea734F of theindicia circuit element732A is in registry with and positioned within theaperture844F. As noted earlier, the layer exposed in theapertures844A-H is theseal coat layer826 which has a sheet resistivity that is greater than about 10⁸Ω/□. Theapertures844A-D defined by the upperpatterned blocking layer842 thus electrically isolate the first capacitive pick-upareas734A of theindicia circuit elements732A-H from the minimallyconductive layer842. Moreover, the upperpatterned blocking layer842 is printed in registry with the lowerpatterned blocking layer808 so that theupper apertures844A-H are aligned with thelower apertures810A-H. The first capacitive pick-upareas734A-H of theindicia circuit elements732A-H therefore are electrically isolated from the minimallyconductive layer808 as well. Theindicia circuit elements732A-H are also printed on theticket700 so that theresistive elements738A-H overlie the play indicia720A-H. For example, theresistive element738A of theindicia circuit element732A overlies the play indicia720A. Similarly, theresistive element738F is printed on theticket700 to overlie the play indicia720F (not shown). Moreover, because the upperpatterned blocking layer842 is printed in registry with the lowerpatterned blocking layer808, the play indicia720A-H are protected against candling.
• [0324]Printing press station786 prints the next layer on the ticket which is a removable scratch-off coating846. As shown in FIG. 71, the scratch-off coating846 is printed as a continuous layer that covers theplay field portion706 of theticket700 and thevalidation number726 within theticket identification portion708 of the ticket. In order not to interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B, the electrical conductivity of the scratch-off coating846 should be significantly less that the electrical conductivity of thecircuit elements732A-H,740,750A, and750B. In the preferred embodiment, the sheet resistivity of the scratch-off coating846 is greater than 10⁸Ω/□. A suitable formulation for the scratch-off coating846 is given in Walton, U.S. Pat. No. 4,726,608. The remaining twoprinting press stations788 and790 apply overprint graphics such as theplay spot areas716A-H, theplay spot graphics718, the void-if-removedarea722, and theoverprint graphics724 and thus provide the finished appearance of theticket700 as shown in FIG. 49.
• The structure of the[0325]ticket700 can be simplified by replacing the separateseal coat layer826, shown in FIG. 63, and the discontinuousrelease coat layer828, shown in FIG. 64, with a combined seal-release coat layer, generally denoted as848. Like therelease coat828, the combined seal-release coat layer848 is not continuous but instead consists ofdiscreet layer portions848A-H that are associated with the play indicia720A-H and a discrete layer portion848I that is associated with thevalidation number736. For example, as shown in FIG. 72 the combined seal-release coat layer848 is printed on theprimer820 so that the seal-releasecoat layer portion848A covers the play indicia720A. Similarly, the combined seal-release coat portion848G covers the play indicia720G. In addition, the seal-release coat portion848I covers thevalidation number726. The combined seal-release coat848 protects the play indicia720A-H and thevalidation number726 against abrasion. The combined seal-release coat848 also ensures that the layers which overlie the play indicia720A-H and thevalidation number726 can be removed to reveal the play indicia720A-H and thevalidation number726. In addition, as explained in reference to FIG. 75, the discrete seal-release coat portions848A-H help to ensure that the electrical signatures of theindicia circuit elements732A-H change when the layers overlying the play indicia720A-H are removed. In order not to interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B, the electrical conductivity of the seal-release coat layer848 should be significantly less than the electrical conductivity of thecircuit elements732A-H,740,750A, and750B. In the preferred embodiment, the sheet resistivity of the seal-release coat848 is greater than about 10⁸Ω/□. However, since the seal-release coat layer848 does not contact any of the capacitive pick-upareas734A-H.736A-H,742A-H,744A-H,752A-B, and754A-B, a lesser sheet resistivity, for example about 10⁷Ω/□, would be acceptable.
• The printing sequence for the ticket changes slightly when the seal-release coat[0326]848 is used instead of the separateseal coat layer826 and the separaterelease coat layer828. Instead of printing theseal coat826 on theprimer layer820,station778 prints the seal-release coat848 on the primer layer.Station780 then prints theupper blocking layer830 as previously described with reference to FIGS.65-67 andstation782 prints theindicia circuit elements732A-H as previously described with reference to FIGS.68-70. It should be noted that when the combined seal-release coat848 is used theprimer layer820, instead of theseal coat layer826, is exposed in thechannels840A and840B defined by the upper barred blockinglayer834 and in theapertures844A-D defined by the upperpatterned blocking layer842. However, like theseal coat layer826 theprimer layer820 has a sheet resistivity that is greater than 10⁸Ω/□. Theticket700 therefore functions in the same manner as described with reference to FIGS.65-70 when the seal-release coat layer848 is used instead of theseparate seal coat826 and theseparate release coat828. This printing sequence also makes it possible to apply theindicia circuit elements732A-H twice, atstations782 and784. As explained below with reference to FIGS.75-76, portions of theindicia circuit elements732A-H are removed when portions of the scratch-off layer846 within theplay spot areas716A-H are removed to reveal the play indicia720A-H. Consequently, the ink used to print theindicia circuit elements732A-H has a reduced graphic adhesiveness relative to the ink used to print theintegrity circuit elements740 and thedata circuit elements750A-B. The reduced graphic adhesiveness of the ink used to print theindicia circuit elements732A-H, coupled with the high speed of thegravure printing press760 can result in small holes, known as picking, in theindicia circuit elements732A-H. FIGS. 73 and 74 present an enlarged representation of one of theindicia circuit elements732A-H, for example, theelement732A. In FIG. 73 asmall portion850 of theindicia circuit element732A has been picked-off during the printing of theelement732A. Similarly, in FIG. 74 a differentsmall portion852 of theindicia circuit element732A has been picked-off during the printing of theelement732A. The resulting discontinuity in theindicia circuit element732A in FIGS,73 and74 can lead to errors in detecting the electrical signature of theindicia circuit element732A. However, if the two illustrations of theindicia circuit element732A in FIGS. 73 and 74 are superimposed, for example, by laying theindicia circuit element732A in FIG. 74 over theindicia circuit element732A in FIG. 73 in registry therewith, the combined image does not suffer from any discontinuities. Therefore, by printing theindicia circuit elements732A-H at two of the stations, for example at thestations782 and784, such that the two layers of theindicia circuit elements732A-H are in registry with each other, discontinuities in the printedindicia circuit elements732A-H can be reduced or eliminated.
• FIG. 75 presents an enlarged view of one of the indicia circuit elements, for[0327]example circuit element720A, and the underlying associated play indicia720A. FIG. 75 also shows the position and configuration of the associated releasecoat layer portion828A or the associated seal-releasecoat layer portion848A. As previously explained, therelease coat828 or the seal-release coat848 is interposed between the play indicia732A-H and theindicia circuit elements732A-H. Although not shown, it is to be understood that theupper blocking layer830 is also interposed between therelease coat828 or the seal-release coat848 and theindicia circuit elements732A-H. As shown in FIG. 75, in the preferred embodiment theresistive element738A is printed over either the releasecoat layer portion828A or the seal-releasecoat layer portion848A so that aportion854 extends beyond the releasecoat layer portion828A or the seal-releasecoat layer portion848A thereby ensuring that the electrical signature of thecircuit element732 changes when the layers overlying the play indicia720 are lifted or removed.
• FIG. 76 shows an alternative embodiment of an indicia circuit element[0328]856 according to the invention. Like theindicia circuit elements732A-H, the indicia circuit element856 includes the first capacitive pick-uparea734, the second capacitive pick-uparea736, and theresistive element738. The main difference between the indicia circuit element856 and theindicia circuit elements732A-H is that the second capacitive pick-uparea736 is no longer aligned with the first capacitive pick-uparea734 but instead is aligned with theresistive element738. This change is of primary importance when theupper blocking layer830 is printed as the barredlayer834 in which case the second capacitive pick-uparea736 of the indicia circuit element856 is printed on theticket700 so that the second capacitive pick-uparea736 either is printed on thestrip836A, within thechannel838A, and or is printed on thestrip836B, within thechannel838B. In all other respects, the indicia circuit element856 operates in the same manner as theindicia circuit elements732A-H.
• The complete structure of the[0329]ticket700 offers several security advantages. The lower and upper blocking layers794 and830 help to protect against surreptitious detection of the play indicia720A-H and thecircuit elements732A-H,740,750A, and750B by candling or fluorescence. Theintegrity circuit740 provides a way of determining if an attempt has been made to alter thebar code730, for example, by cutting and replacing thebar code730. Thedata circuits750A and750B offer at least partial ticket authenticity and integrity information in binary form. Theindicia circuit elements732A-H both protect the play indicia720A-H against fraudulent manipulation and provide a way to verify the gaming value of theticket700. As noted previously with reference to FIGS. 75 and 76, in the preferred embodiment theindicia circuit elements732A-H are printed over either therelease coat portions828A-H or the seal-release coat portions848A-H so that portions854A-H of theresistive elements738A-H extend beyond the releasecoat layer portions828A-H or the seal-releasecoat layer portions848A-H. When one of theplay spot areas716A-H, for example theplay spot area716A, is lifted to reveal the underlying play indicia720A, theresistive element738A will be fractured because the portion854A of theresistive element738A remains affixed to theticket700. Consequently, if an attempt is made thereafter to replace theplay spot area716A and the fracturedresistive element738A, the resulting change in the electrical signature of theindicia circuit element732A is detected by thesensor array502 of theelectronic verification machine500. In addition, when a play spot area such as theplay spot area716A is legitimately removed to reveal the play indicia720A, the electrical continuity between the capacitive pick-uparea734A and736A of theindicia circuit element732A is broken when theresistive element738A is removed with theplay spot area716A. The resulting change in the electrical signature of theindicia circuit element738A can then be detected by thesensor array502 of theelectronic verification machine500, thereby providing a way to determine the gaming value of theticket700.
• IX. A Marker Ticket In Accordance With The Invention.[0330]
• FIGS.[0331]77-83 show amarker ticket860 which can be used with the electronic verification machine500 (shown in FIGS.38-40). Themarker card860 is the type used to record a user's choices relative to pre-set options. For example, marker cards, such as themarker card860, can be used in playing games such as Bingo or Keno. Marker cards like thecard860 are also used to record a user's choice of numbers or other indicia in on-line lottery games. Themarker card860, like theprobability game ticket700, can be used in conjunction with theelectronic verification machine500 of the type shown in FIGS.38-40. FIG. 77 presents the finished appearance of thecard860 which is printed on a substrate, such as paper or card stock, and includes various printed information such as the identity ortitle864 of thecard860,inventory data866, and a machine-readable bar code868. Aboarder869 delineates the play area of thecard860 and is printed as overprint graphics. Thecard860 also includes an indicia-array area870 that has a group of indicia spot areas872A-L, each of which includes an overlay indicia874A-L. The indicia spot areas872A-L and the overlay indicia874A-L are printed as overprint graphics. Each of the indicia spot areas872A-L covers a play indicia876A-L (shown in FIGS.79-81) that is identical to the corresponding overlay indicia874A-L. For example, the overlay indicia874E inindicia spot area872E is a diamond and the play indicia876E (shown in FIGS.79-81), which is located beneath theindicia spot area872E is also a diamond. The indicia spot area872A has been removed to reveal the underlying associated play indicia876A. The overlay indicia874A-L and the play indicia857A-L definelongitudinal data channels877A-C. For example, the overlay indicia874A-D and the associated play indicia876A-D are in thedata channel877A and the overlay indicia874I-L and the associated play indicia876I-L are indata channel877C. The overlay indicia874A-L and the play indicia876A-L are used to represent the pre-set options among which a user can choose.
• The[0332]card860 also includes circuit elements, generally denoted as878, which when coupled to thesensor array502 of theelectronic verification machine500 serve to verify or record the user's chosen options. As shown in FIG. 78 thecard860 has threecircuit elements878A-C, each of which includes a resistive element, generally denoted as880, and an upper and a lower terminal capacitive pick-up area, generally denoted as882 and884, which are connected to and extend from the opposites ends888 and890 of the resistive element880. For example, thecircuit element878A includes theresistive element880A and the two terminal capacitive pick-upareas882A and884A which are aligned with each other and are connected to and laterally extend from thefirst end888A and thesecond end890A, respectively, of theresistive element880A. Each of the circuit element878 also includes intermediate capacitive pick-up areas, generally denoted as892, that are aligned with the terminal capacitive pick-up areas888 and890 and are connected to the resistive elements880 intermediate the terminal capacitive pick-up areas888 and890. For example, thecircuit element878A has three intermediate capacitive pick-upareas892A,892A′, and892A″, that are aligned with the terminal capacitive pick-upareas888A and890A and are connected to theresistive element880A intermediate the terminal capacitive pick-upareas888A and890A. Similarly, thecircuit element878B has three intermediate capacitive pick-upareas892B,892B′, and892B″, that are aligned with the terminal capacitive pick-upareas888B and890B and are connected to theresistive element880B intermediate the terminal capacitive pick-upareas888B and890B. Thecircuit elements878A-C are positioned on thecard860 so that theresistive elements880A-C are aligned with and positioned in the data tracks877A-C defined by the overlay indicia874A-L and the play indicia876A-L and so thatportions894A-L of theresistive elements880A-L are aligned with the overlay indicia874A-L and with the play indicia876A-L. For example, theportion894A-D of theresistive element880A are aligned with the overlay indicia874A-D and with the associated play indicia876A-D. Similarly, the portions8941-L of theresistive element880C are aligned with the overlay indicia874I-L and with the associated play indicia876I-L.
• Several layers are needed to provide the[0333]finished card860 shown in FIG. 77. As shown in FIG. 79, the first layer896 is printed directly on thesubstrate862 and includes the play indicia876A-L. The first layer896 can also include thetitle864, theinventory data866, and thebar code868. The play indicia876A-L are printed on thecard substrate862 with the indicia-array portion870 and are positioned to define thedata channels877A-C. For example, the play indicia876E-H define thedata channel877B. In the preferred embodiment, the play indicia876A-L are printed in a different color than the overlay indicia874A-L in order to make it easier for a user of thecard860 to determine which if the overlay indicia874A-L have been removed. The next layer is aseal coat layer898 that protects the play indicia876A-L against abrasion. As shown in FIG. 80, in the preferred embodiment theseal coat layer898 is printed within the indicia-array portion870 of thecard860 as a continuous layer that overlies the play indicia876A-L. In order not to interfere with the electrical signatures of thecircuit elements878A-C the electrical conductivity of theseal coat layer898 should be significantly less that the electrical conductivity of thecircuit elements878A-C. In the preferred embodiment, the sheet resistivity of theseal coat layer898 is greater than 10⁸Ω/□. A suitable formulation for theseal coat layer898 is given in Walton, U.S. Pat. No. 4,726,608.
• Next, a release coat[0334]900 is printed on thecard860 so that the release coat900 overlies the play indicia876A-L but preferably is not located below any of the capacitive pick-up areas882,884, and892 of thecircuit elements878A-C. For example, as shown in FIG. 81 the release coat900 can be printed as a barred layer902 that includes longitudinally spaced-apart strips904A-D which are printed within and laterally span the indicia-array portion870 of thecard860. Each of thestrips904A-D covers a row of play indicia876A-L. For example, thestrip904A laterally spans the indicia-array portion870 of thecard860 and covers the play indicia876A,876E, and876I. Similarly, thestrip904B covers the play indicia876B,876F, and876J, thestrip904C covers the play indicia976C,876G, and876K, and thestrip904D covers the play indicia876D,876H, and876L. The material exposed between twoadjacent strips904A-D, for example thestrip904A and thestrip904B, is theseal coat layer898 and the material exposed adjacent thestrips904A-D but outside of the indicia-array portion870 of thecard860 is thesubstrate862. Alternatively, as shown in FIG. 82, the release coat layer900 can be printed as a discontinuous layer906 that includes discreetrelease coat spots908A-L each of which covers an associated play indicia876A-L. For example, therelease coat spot908A covers the play indicia876A and therelease coat spot908G covers the play indicia876G. Within the indicia-array portion870 of thecard860 the material exposed between adjacentrelease coat spots908A-L, for example therelease coat spot908B and therelease coat spot908F, is theseal coat layer898. Outside of the indicia-array portion870 of thecard860 the material exposed adjacent therelease coat spots908A-L is thesubstrate862. In order not to interfere with the electrical signatures of thecircuit elements878A-C the electrical conductivity of the release coat layer900 should be significantly less that the electrical conductivity of thecircuit elements878A-C. In the preferred embodiment, the sheet resistivity of the release coat layer900 is greater than 10⁸Ω/□. However, since the release coat layer900 does not underlie any of the capacitive pick-up areas882,884, and892, a lesser sheet resistivity, for example about 10⁷Ω/□, would be acceptable. A suitable formulation for the release coat layer900 is given in Walton, U.S. Pat. No. 4,726,608.
• Alternatively, a combined seal-[0335]release coat910 can be used instead of the separate seal coat and release coat layers898 and900 shown in FIGS.80-82, in which case, the combined seal-release coat910 is printed on thecard860 so that the seal-release coat910 overlies the play indicia876A-L but is not located below any of the capacitive pick-up areas882,884, and892 of thecircuit elements878A-C. For example, as shown in FIG. 83 the seal-release coat910 can be printed as a barred layer912 that includes longitudinally spaced-apart strips914A-D which are printed within and laterally span the indicia-array portion870 of thecard860. Each of thestrips914A-D covers a row of play indicia876A-L. For example, thestrip914A laterally spans the indicia-array portion870 of thecard860 and covers the play indicia876A,876E, and876I. Similarly, thestrip914B covers the play indicia876B,876F, and876J, thestrip914C covers the play indicia976C,876G, and876K, and thestrip914D covers the play indicia876D,876H, and876L. The exposed material around any of thestrips914A-D is thesubstrate862. Alternatively, as shown in FIG. 84, the seal-release coat layer910 can be printed as a discontinuous layer916 that includes discreet seal-release coat spots918A-L each of which covers an associated play indicia876A-L. For example, the seal-release coat spot918A covers the play indicia876A and the seal-release coat spot918G covers the play indicia876G. The exposed material around any of the seal-release coat spots918A-L is thesubstrate862. In order not to interfere with the electrical signatures of thecircuit elements878A-C the electrical conductivity of the seal-release coat layer910 should be significantly less that the electrical conductivity of thecircuit elements878A-C. In the preferred embodiment, the sheet resistivity of the seal-release coat layer910 is greater than 10⁸Ω/□. However, since the seal-release coat layer910 does not underlie any of the capacitive pick-up areas882,884, and892, a lesser sheet resistivity, for example about 10⁷Ω/□, would be acceptable.
• The[0336]circuit elements878A-C are printed on thecard860 immediately after either the release coat900 or the seal-release coat910. Since theportions894A-L of theresistive elements880A-C are removed when the indicia spot areas872A-L and associated portions of the scratch-off layer920 are removed to revel the play indicia876A-L, the ink used to print thecircuit elements878A-C should have a relatively reduced adhesiveness. In addition, the ink used to print the circuit elements should have a relatively high conductivity. In the preferred embodiment, the ink used to print thecircuit elements878A-C has a sheet resistivity of about 1 KΩ/□. A suitable formulation for the ink used to print thecircuit elements878A-L was given previously in Table 5.
• FIG. 85 illustrates the configuration of the[0337]card860 when thecircuit elements878A-C are printed over the barred release coat layer902. As noted earlier with reference to FIG. 78, thecircuit elements878A-C are positioned on thecard860 so that theresistive elements880A-C are aligned with and positioned in the data tracks877A-C. Eachresistive element880A therefore overlies a column of the play indicia876A-L and theportions894A-L of eachresistive element880A-D directly overlie one of the play indicia876A-L. For example, thecircuit element878A overlies the play indicia876A-D and theportions894A-D of theresistive element880A directly overlie the play indicia876A-D. Similarly, thecircuit element878B overlies the play indicia876E-H and theportions894E-H of theresistive element880B directly overlie the play indicia876E-H. In addition, thecircuit element878C overlies the play indicia876I-L and the portions894I-L of theresistive element880C directly overlie the play indicia876I-L. Thus, although the play indicia876A and876G are shown for reference, it should be kept in mind that the play indicia876A and876G would not actually be visible because of theoverlying portions894A and894G of theresistive elements880A and880B, respectively. Similarly, theplay indicia876I and876J, although shown for reference, would not actually be visible because of theoverlying portions894I and894J of theresistive element880C. As previously noted with reference to FIG. 81, each of the longitudinally spaced-apart strips904A-D of the barred release coat902 covers a row of play indicia876A-L so that within the playindicia array portion870 the exposed material betweenadjacent strips904A-D is theseal coat layer898. Moreover, outside of theindicia array portion870 the exposed material adjacent thestrips904A-D is thesubstrate862. Consequently, the terminal capacitive pick-upareas882A-C and884A-C are printed directly on thesubstrate862, as are the intermediate capacitive pick-upareas89A,892A′, and892A″ of thecircuit element878A. The intermediate capacitive pick-upareas892B,892B′, and892B″ of thecircuit element878B and the intermediate capacitive pick-upareas892C,892C′, and892C″ of thecircuit element878C are printed on theseal coat layer898. FIG. 86 illustrates the configuration of thecard860 when thecircuit elements878A-C are printed over the discontinuous release coat layer906. Thecircuit elements878A-C are positioned on thecard860 so that theresistive elements880A-C are aligned with and positioned in the data tracks877A-C. Eachresistive element880A therefore overlies a column of the play indicia876A-L and theportions894A-L of eachresistive element880A-D directly overlie one of the play indicia876A-L. Consequently, although shown for reference the play indicia876A,876G,876I, and876J would not be visible because of theoverlying portions894A,894I,894I, and894J of theresistive elements880A-C. As noted previously with reference to FIG. 82, within the indicia-array portion870 of thecard860 the material exposed between adjacentrelease coat spots908A-L, for example therelease coat spot908B and therelease coat spot908F, is theseal coat layer898. In addition, outside of the indicia-array portion870 of thecard860 the material exposed adjacent therelease coat spots908A-L is thesubstrate862. Consequently, the terminal capacitive pick-upareas882A-C and884A-C are printed directly on thesubstrate862, as are the intermediate capacitive pick-upareas89A,892A′, and892A″ of thecircuit element878A. The intermediate capacitive pick-upareas892B,892B′, and892B″ of thecircuit element878B and the intermediate capacitive pick-upareas892C,892C′, and892C″ of thecircuit element878C are printed on theseal coat layer898.
• FIG. 87 illustrates the configuration of the[0338]card860 when thecircuit element878A-C are printed on the barred seal-release coat912. Thecircuit elements878A-C are positioned on thecard860 so that theresistive elements880A-C are aligned with and positioned in the data tracks877A-C. Eachresistive element880A therefore overlies a column of the play indicia876A-L and theportions894A-L of eachresistive element880A-D directly overlie one of the play indicia876A-L. Consequently, although shown for reference the play indicia876A,876G,876I, and876J would not be visible because of theoverlying portions894A,894G,894I, and894J of theresistive elements880A-C. As noted earlier with reference to FIG. 83, the exposed material around any of thestrips914A-D is thesubstrate862. Consequently, all of the terminal capacitive pick-upareas882A-C and884A-C and all of the intermediate capacitive pick-upareas892A,892A′,892A″,892B,892B′,892B″,892C,892C′, and892C″ are printed directly on thesubstrate862.
• FIG. 88 illustrates the configuration of the[0339]card860 when thecircuit elements878A-C are printed over the discontinuous seal-release coat layer916. Thecircuit elements878A-C are positioned on thecard860 so that theresistive elements880A-C are aligned with and positioned in the data tracks877A-C. Eachresistive element880A therefore overlies a column of the play indicia876A-L and theportions894A-L of eachresistive element880A-D directly overlie one of the play indicia876A-L. Consequently, although shown for reference the play indicia876A,876G,876I, and876J would not be visible because of theoverlying portions894A,894G,894I, and894J of theresistive elements880A-C. As previously noted with reference to FIG. 84, the exposed material around any of the seal-release coat spots918A-L is thesubstrate862. Consequently, all of the terminal capacitive pick-upareas882A-C and884A-C and all of the intermediate capacitive pick-upareas892A,892A′,892A″,892B,892B′,892B″,892C,892C′, and892C″ are printed directly on thesubstrate862.
• A scratch-[0340]off coating920 is then printed on thecard860 so that the scratch-off coating920 span the entireindicia array portion870 of thecard860 and covers all of thecircuit elements878A-C, as shown in FIG. 89. In order not to interfere with the electrical signatures of thecircuit elements878A-C the electrical conductivity of the scratch-off coating920 should be significantly less that the electrical conductivity of thecircuit elements878A-C. In the preferred embodiment, the sheet resistivity of the scratch-off coating920 is greater than 10⁸Ω/□. A suitable formulation for the scratch-off coating920 is given in Walton, U.S. Pat. No. 4,726,608. Theboarder869, the indicia spots areas872A-L and the overlay indicia874A-L are then printed as overprint graphics to give thecard860 the finished appearance shown in FIG. 77.
• The operation of the[0341]circuit elements878A-C is best explained with reference to FIGS. 77, 79, and85-88. Each of the capacitive pick-upareas882A-C,884A-C,892A,892A′,892A″,892B,892B′,892B″,892C,892C′, and892C″ is sized, shaped, and positioned on thecard860 so that each of the capacitive pick-upareas882A-C,884A-C,892A,892A′,892A″,892B,892B′,892B″,892C,892C′, and892C″ can capacitively couple with either theexcitation plate576 or one of thesensor plates574 of thesensor array502 in theelectronic verification machine500. Consequently, all of the intermediate capacitive pick-upareas892A,892A′,892A″,892B,892B′,892B″,892C,892C′, and892C″ function as both excitation and sensor capacitive pick-up areas when thecard860 is coupled to theelectronic verification machine500. The terminal capacitive pick-upareas882A-C and884A-C, however, function only as either an excitation capacitive pick-up area or a sensor capacitive pick-up area depending on the direction in which thecard860 moves through theelectronic verification machine500. For example, if the card moves through theelectronic verification machine500 so that the terminal capacitive pick-upareas882A-C first couple with thesensor array502, then the terminal capacitive pick-upareas882A-C function only as excitation capacitive pick-up areas and the terminal capacitive pick-upareas884A-C function only as sensor capacitive pick-up areas. Alternatively, if the card moves through theelectronic verification machine500 so that the terminal capacitive pick-upareas884A-C first couple with thesensor array502, then the terminal capacitive pick-upareas884A-C function only as excitation capacitive pick-up areas and the terminal capacitive pick-upareas882A-C function only as sensor capacitive pick-up areas. For ease of explanation, in the following discussion it is to be understood that thecard860 moves through theelectronic verification machine500 so that the terminal capacitive pick-upareas882A-C first couple with thesensor array502 and so function only as excitation capacitive pick-up areas. Referring now to FIGS.85-88, when thecard860 first couples with thesensor array502, the terminal capacitive pick-uparea882C serves as an excitation capacitive pick-up area and the intermediate capacitive pick-uparea892C serves as a sensor capacitive pick-up area. In addition, the terminal capacitive pick-uparea892C is joined to the intermediate capacitive pick-uparea892C by the portion894I of theresistive element880C. The capacitive pick-upareas882C and892C and the associated portion894I of theresistive element880C therefore form a U-shaped circuit element. As thecard860 continues to move through theelectronic verification machine500, the intermediate capacitive pick-uparea892C and the intermediate capacitive pick-uparea892C′ function as excitation and sensor capacitive pick-up areas, respectively, that are joined by theportion894J of thecircuit element880C. Similarly, the intermediate capacitive pick-uparea892C′ and the intermediate capacitive pick-uparea892C″, together with theportion894K of theresistive element880C form a U-shaped circuit element, and the intermediate capacitive pick-uparea892C″ and the terminal capacitive pick-uparea884C, together with theportion894L of theresistive element880C form a U-shaped circuit element. Each of the circuit elements878 therefore serves as a linear array of U-shaped circuit elements that are defined by two adjacent capacitive pick-up areas,882A-C and892A-C,892A-C and892A′-C′,892A′-C′ and892A″-C″,892A″-C″, and884A-C, and the associatedportions894A-L of theresistive elements880A-C. Thus, when a given indicia spot area872A-L is removed to mark thecard860 and reveal the underlying play indicia876A-L, only the U-shaped circuit element which is partially defined by the associatedportion894A-L of theresistive element880A-C is affected. For example, when the indicia spot area872A is removed to reveal theunderlying play indicia876A as shown in FIG. 77, the only affected U-shaped circuit element is the one that is defined by the terminal capacitive pick-uparea882A, the intermediate capacitive pick-uparea892A and the associatedportion894A of theresistive element880A.
• It should be kept in mind that a similar result can be achieved if the card is printed with a plurality of separate U-shaped circuit elements, such as the[0342]data circuit elements750A-B of theticket700. However, the method of printing the circuit elements878 has advantages over printing individual U-shaped elements such as750A-B in that much fewer capacitive pick-up areas are required for each data bit. Also, for those applications where the play indicia876A-L are not required, theseal coat898 can be omitted from themarker card860.
• X. A Data Card According To The Invention.[0343]
• FIG. 90 shows a[0344]data card922 which can be used with theelectronic verification machine500, shown in FIGS.38-40. Thedata card922 includes circuit elements, generally denoted as924, that are printed directly on asubstrate926. Each of the circuit elements924 includes two terminal capacitive pick-up areas, generally denoted as928 and930, and a data track, generally denoted as932, that spans between the two terminal capacitive pick-up areas928 and930. In addition, each of the circuit elements924 can include intermediate capacitive pick-up areas, generally denoted as934,936, and938, that are positioned on thecard922 intermediate the terminal capacitive pick-up areas928 and930 and are aligned with the terminal capacitive pick-up areas928 and930. As with themarker card860, each pair of adjacent capacitive pick-up areas, for example, the capacitive pick-uparea928B and the capacitive pick-uparea934B, or the capacitive pick-uparea934B and the capacitive pick-uparea936B, define partial U-Shaped circuit elements the remainder of which are defined by an associatedportion940A-L of the data tracks932. The U-shaped circuit elements can in turn encode either a bit-off or “0” signal or a bit-on or “1” signal, depending on whether or not the associatedportions940A-L of the data tracks932 contain conductive material. For example, the U-shaped circuit element that is defined by the capacitive pick-upareas928A and934A and the associatedportion940A of thedata track932A encode a bit-off or “0” signal and the U-shaped circuit element that is defined by the capacitive pick-upareas928B and934B and the associatedportion940E of thedata track932B encodes a bit-on or “1” signal. Thus, reading from left to right, the first row of U-Shaped circuit elements encodes “011”, the second row of U-Shaped circuit elements encodes “110”, the third row of U-shaped circuit elements encodes “100” and the fourth row of U-shaped circuit elements encodes “111”. A suitable ink for printing thecircuit elements924A-C for thedata card922 can be printed with the ink that was previously described in Table 1.
• FIG. 91 illustrates an alternative embodiment of a[0345]data card942 according to the invention. Like thedata card922, thedata card942 includescircuit elements924A-C. The main difference between thedata card922 and thedata card942 is that thedata card942 includes arelease coat944 that is printed on thesubstrate926 so that the release coat underlies theportions940A-L of the data tracks932A-C but does not underlie any of the capacitive pick-upareas928A-C,930A-C,934A-C,936A-C, and938A-C. As with themarker card860, therelease coat944 can be printed on thesubstrate926 either as discreet releasecoat layer portions946A-F or as spaced-apart strips948A-B. Thecircuit elements924A-C are therefore printed on thedata card942 so that initially each of the data tracks932A-C contains conductive material in all of theportions940A-L of the data tracks932A-C. After thedata card942 is printed,specific portions940A-L of the data tracks932A-C are scratched-off to encode the desired binary data. For example theportion940A of theresistive track932A, theportion940G of thedata track932B, and theportions940J and940K of thedata track932C have been removed subsequent to printing thedata card942. Thus, reading from left to right, the first row of U-Shaped circuit elements encodes “011”, the second row of U-Shaped circuit elements encodes “110”, the third row of U-shaped circuit elements encodes “100” and the fourth row of U-shaped circuit elements encodes “111”. A suitable ink for printing thecircuit elements924A-C for thedata card942 was previously given in Table 1.
• XI. A Laminated Document According To The Invention.[0346]
• FIG. 92. shows a[0347]laminated document950 that can be used with the electronic verification machine (shown in FIGS.38-40). Laminated documents, such as thedocument950, have a variety of uses including protecting an information document against excessive wear. One example of a laminated document, such as thedocument950, is an identification card such as a driver's license where the information document is a photograph. Laminated documents, such as identification cards, can be altered, for example, by splitting the laminated document to remove the original identification document and then substituting a fraudulent identification document. The laminated document905 helps to prevent such fraudulent misuse. As shown in FIG. 92, thedocument950 includes afirst laminate952, asecond laminate954, and aninformation document956, such as a photograph. Thelaminated document950 also includes twocircuit elements958 and960, each of which is secured to or printed on one of thelaminates952 and954. FIG. 93 illustrates thefirst laminate952 which includes anupper surface962 on which thecircuit element958 is printed. The laminate952 preferably is made from a durable non-conductive material, such as plastic, that can be opaque and that has a sheet resistivity greater than 10⁸Ω/□. The outline of theinformation document956 is shown in phantom for reference. Thecircuit element958 includes two capacitive pick-upareas964 and966. The capacitive pick-uparea966 is shaped and positioned on theupper surface962 of the laminate952 so that the capacitive pick-uparea966 capacitively couples with theexcitation plate576 of thesensor array502 in theelectronic verification machine500. The capacitive pick-uparea964 is shaped and positioned on theupper surface962 of the laminate952 so that the capacitive pick-uparea964 capacitively couples with one of thesensor plates574 of thesensor array502. Thecircuit element952 further includes aresistive element968 that is connected to and extends between the capacitive pick-upareas964 and966 so that at least aportion970 of theresistive element968 underlies theinformation document956 in thelaminated document950.
• FIG. 94 illustrates the[0348]second laminate954 which includes alower surface972 on which thecircuit element960 is printed. The laminate954 preferably is made from a transparent material, such as plastic, that has a sheet resistivity greater than 10⁸Ω/□. The outline of theinformation document956 is shown in phantom for reference. Thecircuit element960 includes two capacitive pick-upareas974 and976. The capacitive pick-uparea976 is shaped and positioned on thelower surface972 of the laminate954 so that the capacitive pick-uparea976 capacitively couples with theexcitation plate576 of thesensor array502 in theelectronic verification machine500. The capacitive pick-uparea974 is shaped and positioned on thelower surface972 of the laminate954 so that the capacitive pick-uparea974 capacitively couples with one of thesensor plates574 of thesensor array502. Thecircuit element954 further includes aresistive element978 that is connected to and extends between the capacitive pick-upareas974 and976 so that at least aportion980 of theresistive element978 overlays theinformation document956 in thelaminated document950. A suitable ink for printing thecircuit elements968 and069 was presently previously in Table 1.
• In making the finished[0349]laminated document950 shown in FIG. 92, theinformation document956, shown in FIG. 95, is positioned on thefirst laminate952 so that theportion970 of theresistive element960 underlies theinformation document950. Thesecond laminate954 is then inverted, relative to its configuration in FIG. 94, so that thelower surface972 of thesecond laminate954 is adjacent theupper surface962 of thefirst laminate952. Thesecond laminate954 is also aligned with theinformation document956 so that theportion980 of thecircuit element960 overlies theinformation document956. The twolaminates952 and954 are then bonded together to form thelaminated document950. Thereafter, if an attempt is made to split thelaminated document950 and remove theinformation document956, one or both of theresistive elements968 and978 will be damaged or broken. The resulting change in the electrical signature of the affectedcircuit element958 or960 can then be detected by thesensor array502 of theelectronic verification machine500.
• XII. A Third Electronic Verification Machine[0350]
• A. Components[0351]
• A third and preferred embodiment of an[0352]electronic verification machine1000 according to the invention is shown in FIG. 96. Theelectronic verification machine1000 includes a frame structure1002 (shown in FIG. 97) which is enclosed within ahousing1004 that includes acover section1006, abottom section1008, and afront section1010. Although the exact configuration of the exterior of theelectronic verification machine1000 can vary, the exterior of theelectronic verification machine1000 preferably includes adisplay panel1012, auser interface1014, and adocument interface1016, all of which are positioned along thecover section1006. Thedisplay panel1012 can display instructions, such as “Insert Ticket” and can also display the results of document validation and verification testing. Thedisplay panel1012 preferably consists of a commercially available display unit, such as a liquid crystal display, a gas discharge display, or a light emitting diode (LED) display. Theuser interface1014 includes a numeric keypad, shown generally as1018, and function keys, shown generally as1020. The operator can use theuser interface1014 to manually enter data from the document into theelectronic verification machine1000. Thedocument interface1016 includes aslot1022 into which the document to be tested is inserted. In the preferred embodiment, thedocument interface1016 also includes anexit slot1024 from which the document being tested exits theelectronic verification machine1000. In addition, theelectronic verification machine1000 preferably includes adoor1026 located on thefront section1010 of thehousing1004. Thedoor1026 provides access to the document pathway and can be used to clear the pathway should the document become jammed within theelectronic verification machine1000. Thedoor1026 also provides access to a mirror1028 (shown in phantom) that is positioned along the inner surface of thedoor1026. As explained below, themirror1028 can be used to read certain kinds of data printed on the document. Thedoor1026 and associatedfront section1010 also include adoor position sensor1029.Indicator lights1030 located on thefront section1010 can be used to indicate that thedoor1026 is open or jammed, that a document is jammed within the document channel1038, or that theelectronic verification machine1000 is unable to scan a document.
• FIG. 97 shows the[0353]electronic verification machine1000 with thehousing1004 removed. Theframe structure1002 includes abase portion1032 and afront portion1034 that is generally aligned with thefront section1010 of the housing1004 (as shown in FIG. 96). Asensor head1036 is secured to theframe structure1002 to form a channel1038 intermediate thefront portion1034 of theframe structure1002 and thesensor head1036. The channel1038 defines the document pathway through theelectronic verification machine1000. In the preferred embodiment of the invention, thesensor head1036 is tensionably secured to theframe structure1002 so that the document being tested is in intimate physical contact with a sensor array1044 (shown in FIGS. 99 and 100) positioned on thesensor head1036. Thesensor head1036 therefore includes hinge pins1040 that are rotatably mounted inhinge arms1042 formed on thefront portion1034 of theframe structure1002. Atensioning guide1046 is located along thesensor head1036, opposite thefront portion1034 of theframe structure1002 and is secured to theframe structure1002 by tensioningfasteners1048. Thetensioning guide1046 is preferably formed from a rigid material, such as metal, and thetensioning fasteners1048 can be formed from any appropriate stretchable devices, such as springs. Thetensioning guide1046 helps to ensure that the document being tested maintains intimate physical contact with thesensor array1044 while the hinge pins1040 permit thesensor head1036 to pivot slightly so that theelectronic verification machine1000 can accept documents of varying thickness. Aribbon connector1050 extends through an aperture1052 (shown in FIG. 98) formed in thetensioning guide1046 and operatively connects thesensor head1036 to a mastercontrol processing board1054 which is affixed to theframe structure1002.
• The[0354]electronic verification machine1000 also includes apressure roller1056 which moves the document being tested through the document channel1038 and through the exit slot1024 (shown in FIG. 96). Thepressure roller1056 is supported in theframe structure1002 via ashaft1055 which also supports apulley1057. Astepper motor1058 is also supported on theframe structure1002 via ashaft1059, on which is also mounted apulley1060. Atoothed belt1061 looped around thepressure roller pulley1057 and thestepper motor pulley1060 connects thepressure roller1056 to thestepper motor1058. As explained in more detail below, thestepper motor1058 is operatively connected to the mastercontrol processing board1054 and controls the rate at which the document being tested is moved through the document channel1038. In addition,edge detectors1062 and1064 (shown in FIG. 98), which are operatively connected to the mastercontrol processing board1054 by sets oflines1066 and1068 and byribbon connector1050, provide information about the position of the document being tested within the document channel1038. Theelectronic verification machine1000 further includes abar code reader1070 which is secured to theframe structure1002 and is operatively connected to the mastercontrol processing board1054 viaconnector lines1072.
• FIG. 98, which is a partially cut-away exploded side perspective view of the[0355]electronic verification machine1000, shows the relationship among thecover section1006 of thehousing1004, thefront portion1034 of theframe structure1002, thesensor head1036, thetensioning guide1046, and thefront section1010 of thehousing1004 in more detail.
• The[0356]user display panel1012 and theuser interface1014, located along thecover portion1006, are operatively connected to the mastercontrol processing board1054 via aribbon connector1015. When theelectronic verification machine1000 is fully assembled, theticket slot1022 formed in thecover portion1006 is aligned with the document channel1038 (shown in FIG. 97) which is formed between thefront portion1034 of theframe structure1002 and thesensor head1036. Thepressure roller1056 extends through anaperture1074 formed in thefront portion1034 of theframe structure1002. Consequently, thepressure roller1056 contacts the document being tested and moves the document through the document channel1038 (shown in FIG. 97). In the preferred embodiment, theedge detectors1062 and1064 consists of two light emittingdiodes1076 and1078 and twophototransistors1080 and1082. Thelight emitting diodes1076 and1078 are positioned along thefront portion1034 of theframe structure1002 on opposite sides of thepressure roller1056. Thephototransistors1080 and1082 are positioned along thesensor head1036 on opposite sides of a sensorarray circuit board1084 which is secured to thesensor head1036. Thephototransistors1080 and1082 on thesensor head1036 are aligned with thelight emitting diodes1076 and1078 on theframe structure1002 to form theedge detectors1062 and1064. Thefirst edge detector1062 is used to indicate that a document has been inserted into theelectronic verification machine1000. Thesecond edge detector1064 is used to obtain precise document position information. Thefirst edge detector1062 and thesecond edge detector1064 are spaced-apart by a pre-determined distance which, in the preferred embodiment, is about 1.48 inches. In addition, thesecond edge detector1064 is located at a pre-determined distance, preferably 0.73 inches, below the tangent point of thepressure roller1056.
• The[0357]electronic verification machine1000 also includes awindow1086 formed along thefront portion1034 of theframe structure1002. Thewindow1086 is aligned with both thebar code reader1070 and themirror1028 located along thefront section1010 of thehousing1004. Together, themirror1028 and thewindow1086 can be used with thebar code reader1070 to read bar codes that are printed on the front of the document being tested. Alternatively, bar codes that are printed on the back of the document being tested can be read by thebar code reader1070 and thewindow1086 alone. As noted earlier, theelectronic verification machine1000 can also includeindicator lights1030 located on thefront section1010 of thehousing1004. The indicator lights1030 are operatively connected to the door position sensor1029 (shown in phantom) which also is located on thefront section1010 and which, in the preferred embodiment, includes a light emitting diode and a phototransistor. Thedoor position sensor1029 and theindicator lights1030 are operatively connected to the mastercontrol processing board1054 bylines1090 and1092, respectively.
• FIG. 99 is a block diagram of the relationship among the major components of the[0358]electronic verification machine1000. Thesensor head1036 is connected to the mastercontrol processing board1054 by theribbon connector1050. Thelight emitting diodes1076 and1078 which form parts of theedge detectors1062 and1064, respectively, are connected to the mastercontrol processing board1054 by thelines1066 and1068, respectively. Thedoor position sensor1029 is connected to the mastercontrol processing board1054 by theline1090, while theindicator lights1030 are operatively connected to the mastercontrol processing board1054 by theline1092. Aline1094 operatively connects thestepper motor1058 to the mastercontrol processing board1054. Thelines1072 operatively connect thebar code reader1070 to the mastercontrol processing board1054. Theuser interface1014 is operatively connected to the mastercontrol processing board1054 by theribbon connector1015. The electronic verification machine also includes astigmatization circuit1096 which is used in conjunction with thesensor array1044 and the mastercontrol processing board1054 to stigmatize a document being tested once its electrical signature has been measured. Thestigmatization circuit1096 is operatively connected to thesensor array1044 bylines1098 and to the mastercontrol processing board1054 bylines1100.
• In the preferred embodiment of the invention, master[0359]control processing board1054 includes two microcontrollers, a support microcontroller1102 and aprimary microcontroller1104. The support microcontroller1102 is used in controlling all low-level device interfaces, such as thesensor array1044. thestigmatization circuit1096, theedge detectors1062 and1064, thedoor position sensor1029, theindicator lights1030, theuser interface1014, thebar code reader1070 and thestepper motor1058. A set of lines1106-1110 provides signal inputs and outputs to the support microcontroller1102. In the preferred embodiment of the invention, the support microcontroller1102 is a Motorola MC68HC16 processor which incorporates a 16 bit central processing unit, a single chip integration module, a multi-channel communications interface, a general purpose timer and a time processing unit. The support microcontroller also includes an 8 to 10 bit analog-to-digital (A/D) converter1112 andmemory1114. Thememory1114 of the support microcontroller1102 preferably includes 48 Kbytes of Programmable Read Only Memory (PROM) and 65 Kbytes of Static Random Access Memory (SRAM). Thebar code reader1070 is connected to the support microcontroller1102 by a standard bidirectional UART port operating at 9600 Baud. The internal timers of the support microcontroller1102 are used to control thestepper motor1058. Theedge detectors1062 and1064 are interfaced to the support microcontroller as standard Transistor-Transistor Logic (TTL) signals.
• The[0360]primary microcontroller1104 is used to process the electrical signature of the document being tested in order to verify that the document is authentic. In the preferred embodiment of the invention, theprimary microcontroller1104 preferably is a 32 bit Elan SC410A which operates at an internal clock speed of 66 MHz. Theprimary microcontroller1104 also includesmemory1116 which, in the preferred embodiment consists of 4-8 Mbytes of Dynamic Random Access Memory (DRAM), 2-4 Mbytes of flash memory, and 512 Kbytes to 1 Mbyte of SRAM supported by a back up battery. In the preferred embodiment of the invention, theprimary microcontroller1104 includes a glueless burst-mode interface that allows the flash memory to be partitioned in to various sectors, e.g., operating system, operational software version A, operational software version B, etc. Theprimary microcontroller1104 is connected to the support microcontroller1102 by a highspeed parallel interface1118. Aparallel interface1120 connects theprimary microcontroller1104 to a Dual Universal Asynchronous Receiver-Transmitter (DUART)1122 which is also connected by a serial digital line at Transistor Transistor Logic (TTL) levels to amodem1126. In the preferred embodiment of the invention, themodem1126 is a 14.4 kbps Rockwell modem. Themodem1126 is used to provide communications between theelectronic verification machine1000 and a central site computer, such as the computer223 (shown in FIG. 17).
• As mentioned earlier, the support microcontroller[0361]1102 is used for all low level device interfaces. Consequently, theprimary microcontroller1104 is used only for high level functionality such as comparing the measured electrical signature to a predetermined game signature map such as shown in FIG. 44. In addition, theprimary microcontroller1104 communicates with thecentral site computer223 to obtain game specific information such as thegame signature map632, and to determine the redemption value of high level probability game lottery tickets, such as theticket700. To maximize communications flexibility with the central site computer, the electronic verification machine can also be equipped with an optional Motorola MC68302 communications processor (not shown). This communications processor would then be used to handle all low-level communications protocols, thereby allowing theprimary microcontroller1104 to focus exclusively on high-level ticket/user functionality.
• FIG. 100 is a top plan view of the[0362]sensor head1036 and shows thesensor array1044 in more detail. Thesensor head1036 includes thephototransistors1080 and1082 that form parts of theedge detectors1062 and1064 (shown in FIG. 98) and the sensorarray circuit board1084 of which thesensor array1044 forms a part. In the preferred embodiment, the sensorarray circuit board1084 is secured to asensor head housing1128 which also carries thephototransistors1080 and1082. Due to the intimate physical contact between the document being tested and thesensor head1036, if not protected thephototransistors1080 and1082 can become dirty over time due to contact with the document being tested. Consequently, in the preferred embodiment of the invention, thephototransistors1080 and1082 are embedded within and protected by thesensor head housing1128 which is formed from a plastic that is transparent in the infrared region. In the preferred embodiment, a clear Acrylic with a 94-V0 flame rating is used to form thesensor head housing1128.
• The[0363]sensor array1044 includes anelongated excitation plate1130, thirteensensor plates1132A-1132M, and afuse excitation pad1134. It should be noted that, in an embodiment of the invention that does not include stigmatization, thefuse excitation pad1134 can be replaced with a sensor plate to provide fourteen document sensor channels. The vertical dimension of each of thesensor plates1132A-1132M preferably is 0.1 inches and the horizontal dimension of each of thesensor plates1132A-1132M preferably is 0.1 inches. The vertical dimension of theexcitation plate1130, which preferably is located about 0.05 inches from thesensor plates1132A-1132M, preferably is 0.1 inches. The horizontal dimension of thefuse excitation pad1134 preferably is about 0.1 inches and the vertical dimension preferably is about 0.26 inches. Thesensor array1044 can also include athin ground strap1136 positioned intermediate theexcitation plate1130 and thesensor plates1132A-1132M. Because of the close proximity of theexcitation plate1130 and thesensor plates1132A-1132M, the excitation signal can jump between theexcitation plate1130 and thesensor plates1132A-1132M, resulting in an inaccurate electrical signature. Theground strap1136 behaves as an “electrical fence” and prevents signal jumping from theexcitation plate1130 to thesensor plates1132A-1132M. The inter-sensor plate spacing should be about twice the horizontal dimension of thesensor plates1132A-1132M. In the preferred embodiment of the invention, the spacing between any twoadjacent sensor plates1132A-1132M, such as thesensor plates1132B and1132C, is about 0.18 inches. The horizontal dimension of theexcitation plate1130 is chosen so that theexcitation plate1130 spans the distance of the thirteensensor plates1132A-1132M. In the preferred embodiment of the invention, the horizontal dimension of theexcitation plate1130 therefore is about 3.46 inches.
• The[0364]excitation plate1130, thesensor plates1132A-1132M, thefuse excitation pad1134, and theground strap1136 preferably are made from a highly conductive material, such as copper. However, it has been found that over time thesensor array1044 can become worn due to the close physical contact of the document being tested. Consequently, in the preferred embodiment of the invention, theexcitation plate1130, thesensor plates1132A-1132M, thefuse excitation pad1134, and theground strap1136 are initially formed as a three-part layer consisting of copper, covered by nickel, covered by a thin layer of gold. The nickel protects the copper surface and protects thesensor array1044 from undue wear and tear. The thin gold layer allows other parts of the sensor array circuit to be soldered onto the sensorarray circuit board1084. Over time, the gold layer covering thesensor array elements1130,1132A-1132M,1134, and1136 wears away leaving only the nickel-coated copper layer. The thin gold layer over thesensor array elements1130,1132A-1132M,1134, and1136 thus serves as a sacrificial mask while the thin gold layer on other portions of the sensorarray circuit board1084 permits soldering of other sensor head components.
• It has also been found that, because of the close physical contact between the[0365]sensor array1044 and the document being tested, irregularities along thetop surface1138 of the sensorarray circuit board1084 can cause the document to become jammed in the document channel1038 (shown in FIG. 97). Consequently, care must be taken in fabricating the sensorarray circuit board1084 to ensure that thesensor array elements1130,1132A-1132M,1134, and1136 are essentially flush with thetop surface1138 of the sensorarray circuit board1084. Preferably, thesensor array elements1130,1132A-1132M,1134, and1136 project less than 0.00006 inches from thetop surface1138. If necessary, a non-conductive epoxy film can be applied to thetop surface1138 to achieve this goal.
• The general operation of the[0366]electronic verification1000 to measure the electrical signature and other verification data of a document will now be explained with reference to theticket700, shown in FIG. 49. Referring now to FIGS.96-100, the document to be tested, such as theticket700, is placed in thedocument ticket slot1022 so that the back822 of theticket700 faces thefront portion1034 of theframe structure1002. Theticket700 drops into the document channel1038 until it reaches the top of thepressure roller1056. At this point, thefirst edge detector1062 signals the support microcontroller1102 that theticket700 is present in the document channel1038. Consequently, the support microcontroller1102 provides a first pulse rate to thestepper motor1058 which rotates thepressure roller1056 at a first rate to move theticket700 down the ticket channel1038 past thesensor head1036. In the preferred embodiment of the invention, thestepper motor1058 advances theticket700 in discrete steps of about 0.02 inches per step. The first pulse rate supplied by the support microcontroller1102 preferably is 300 steps per second. Thus, thepressure roller1056 initially moves theticket700 in the document channel1038 at a rate of about six inches per second. As soon as thestepper motor1058 has been activated, the support microcontroller1102 activates the sensorarray circuit board1084 so that thesensor array1044 measures the electrical signature of theticket700. Theelectronic verification machine1000 measures the electrical signature of the document being tested, such as theticket700, by capacitively coupling an excitation signal from the triangular waveform generator510 (shown in FIGS. 40, 41, and101) to the document via theexcitation plate1130. Since there are thirteensensor plates1132A-1132M, thesensor array1044 provides thirteen sensed electrical signature values for each step of thestepper motor1058. The thirteen sensed electrical values are forwarded to associated amplifiers. The processed signal is then sampled by the 8-bit A/D converter1112. The 8-bit values of the sampled signals are then passed to theprimary microcontroller1104 for analysis.
• As the[0367]stepper motor1058 moves theticket700 through the document channel1038 at the first pulse rate, the leading edge of theticket700 eventually passes thesecond edge detector1064 and thereby activates thesecond edge detector1064. Thestepper motor1058 then continues to move theticket700 through the document channel1038 via thepressure roller1056 until the support microcontroller1102 determines that thebar code730, which is printed on the ticket identification portion708 (shown in FIG. 49) of theticket700, is in position for reading by thebar code reader1070. Thebar code730 is printed on theticket700 at a predetermined position, relative to the leading and following edges of theticket700. Since theticket700 moves through the document channel1038 at a pre-determined rate, in this case a rate of 0.02 inches per step, the location of the leading edge of theticket700 involves simply counting the number of stepper motor steps which have occurred since thesecond edge detector1064 was activated. Once theticket700 is in position for thebar code reader1070 to read thebar code730, the support microcontroller1102 provides a second pulse rate to thestepper motor1058 so that theticket700 moves at a second pre-determined rate while thebar code730 is being read. Thebar code reader1070 operates at a pre-determined rate which, in the preferred embodiment of the invention is thirty Hertz. Consequently, the rate at which theticket700 moves past thebar code reader1070 must be slower than the initial rate at which theticket700 moves through the document channel1038 to ensure an accurate reading of thebar code730. Therefore, in the preferred embodiment of the invention, the second pulse rate provided by the support microcontroller1102 is15 steps per second so that thebar code730 on theticket700 moves past the fixedbar code reader1070 at a rate of 0.3 inches per second. If thebar code reader1070 is not able to read thebar code730, thestepper motor1058 continues to move theticket700 at the second rate until the support microcontroller1102 determines that thebar code730 has moved completely past thebar code reader1070. Since thebar code730 has a pre-determined height, determining that thebar code730 has moved past thebar code reader1070 involves counting the stepper motor steps which have occurred since the support microcontroller1102 initiated the second pulse rate. If thebar code reader1070 still has not been able to read thebar code730, the support microcontroller1102 stops thestepper motor1058 and sends a reverse pulse rate to thestepper motor1058 so that theticket700 is moved back out through thedocument slot1022, thereby alerting the operator that thebar code730 has not been read.
• Once the[0368]bar code730 is read by thebar code reader1070, the support microcontroller1102 again sends the first pulse rate to thestepper motor1070 to move theticket700 through the document channel1038 at the first rate until the following edge of theticket700 passes thefirst edge detector1062 and thereby inactivates thefirst edge detector1062. The support microcontroller1102 then calculates the number of additional stepper motor steps needed to move theticket700 past the sensor head, based on the pre-determined distance between thefirst edge detector1062 and thesecond edge detector1054. Thestepper motor1070 then continues to move theticket700 at the first pre-determined rate for the calculated number of stepper motor steps needed for theticket700 to clear the sensor head1102. At this point, the support microcontroller1102 deactivates both thestepper motor1058 and thesensor head1036. The measured electrical signature value of the document being tested is then transmitted theprimary microcontroller1104 for verification analysis.
• In addition to providing document position information to the support microcontroller[0369]1102 while theticket700 is being read by theelectronic verification machine1000, theedge detectors1062 and1064 also provide information which controls how the support microcontroller1102 responds if theticket700 becomes jammed in theelectronic verification machine1000. For example, the operator may inadvertently place an improperly sized document into theelectronic verification machine1000. If the document is too short, thefirst edge detector1062 can become deactivated before the leading edge of the document passes thesecond edge detector1064 and the document can become jammed in the document channel1038. The support microcontroller1102 uses the pre-determined distance between thefirst edge detector1062 and thesecond edge detector1064 to determine if a short ticket has been inserted into theelectronic verification machine1000. The number of stepper motor pulses needed to move the leading edge of a document from thefirst edge detector1062 to thesecond edge detector1064 is pre-determined by the distance between thefirst edge detector1062 and thesecond edge detector1064 and by the size of each stepper motor step. If thefirst edge detector1062 is deactivated before thesecond edge detector1064 is activated, the document must be less than1.478 inches long. Once the leading edge of the document activates thesecond edge detector1064, 0.73 inches of the ticket must have moved from the tangent point of thepressure roller1056 to thesecond edge detector1064, leaving at most 0.75 inches of the ticket to be moved through the document channel1038 past the second edge detector. As previously stated, the first pre-determined pulse rate moves the document at 0.02 inches per stepper motor step. Consequently, the support microcontroller1102 continues to provide the first pulse rate to the stepper motor for an 38 additional stepper motor steps, at which time the document should be past thesecond edge detector1064 and free of the document channel1038.
• The[0370]edge detectors1062 and1064 can also be used to provide data that helps to verify the authenticity of the document being tested. For example, when the document being tested is a probability game lottery ticket, such as theticket700, the size of theticket700 can be used to help determine if the ticket is authentic. Once the ticket has passed completely though thedocument channel108, the size of the ticket can be determined by counting the number of stepper motor steps which have occurred between the activation and deactivation of thesecond edge detector1064. The measured value for the size of theticket700 can then be compared to a pre-determined value for the size of theticket700 to provide an additional parameter by which the authenticity of theticket700 can be tested.
• B. Determining The Electrical Signature[0371]
• One of the objects of the[0372]electronic verification machine1000 is to determine the electrical signature of the document being tested. When the document being tested consists of a probability game ticket, such as the ticket700 (shown in FIG. 49), the electrical signature consists of a two-dimensional array or grid which represents the location and amount of conductive material found on the document. Thesensor array1044 of theelectronic verification machine1000 is used to scan theplaying field portion706 and theticket identification portion708 of theticket700 to determine the amount and location of conductive materials and to generate a scanned data map or scratch map, such as that shown in FIG. 45. The primary electrical signature value that thesensor array1044 detects is the total capacitance of theexcitation plate1130 and a given one of thesensor plates1132A-1132M. In general, capacitance is defined by Maxwell's equation:
• C=Kε₀(A/T)
• where K is the dielectric constant of the insulating material separating the conductive planes of the capacitor, A is the intersecting area of the conductive planes, T is the thickness of the insulating material and ε[0373]₀is the permittivity of free space. When thesensor array1044 is capacitively coupled to the document being tested, such as theticket700, theexcitation plate1130 and a given one of thesensor plates1132A-1132M, such as thesensor plate1132A, function as two capacitors C1 and C2 whose capacitance depends on the nature and amount of conductive material on the portions of theticket700 which underlie theexcitation plate1130 and thesensor plate1132A.
• A simplified partial circuit diagram of the capacitive coupling between the[0374]sensor array1044 and the document being tested, such as theticket700, is shown in FIG. 101. C_t1represents the capacitance between theexcitation plate1130 and the document being tested and C_t2represents the capacitance between the document and one of thesensor plates1132A-1132M, such as thesensor plate1132A. The portion of theticket700 which is intermediate theexcitation plate1130 and thesensor plate1132A functions as a resistor having a resistance represented by R_tand effectively connects in series the capacitors C1 and C2 formed at theexcitation plate1130 and thesensor plate1132A, respectively. Consequently, the total coupling capacitance C_totalis the combined capacitances of C_t1and C_t2. The magnitudes of C_t1and C_t2depend on the nature and amount of conductive material on the portions of theticket700 which underlie theexcitation plate1130 and thesensor plate1132A. Referring back to FIGS.49-71, it will be recalled that theticket700 is printed in several different layers. One of the conductive layers printed on theticket700, such theintegrity circuit element740 layer, theindicia circuit elements732A-732H layer, or theupper blocking layer830, serves as the conducting plane in theticket700 which operates with theexcitation plate1130 and thesensor plate1132A to form the two capacitors C1 and C2. The printed layers which lie between theexcitation plate1130 and the conductive layer and which lie between thesensor plate1132A and the conductive layer serve as the insulating medium whose thickness and dielectric constant affect the magnitudes of C_t1and C_t2. The particular conductive layer which forms the conducting plane in theticket700 varies depending on the portion of theticket700 which is capacitively coupled to thesensor array1044, as do the particular layers which form the insulating medium.
• It will be recalled that the final form of the[0375]ticket700 includes several different printed layers. The characteristics of the inks used to print the various layers affects the electrical signature measured by theelectronic verification machine1000. When theelectronic verification machine1000 is used to determine the electrical signature of a probability game ticket, such as theticket700, the preferred first layer794 (shown in FIG. 52) is an opaque blocking layer that helps to protect the play indica720A-H and thecircuit elements732A-H,740,750A, and750B, from surreptitious detection by candling. In the presently preferred embodiment of the invention, thefirst layer794 ideally is non-conductive relative to conductive layers, such as the layer ofintegrity circuit elements740 and the layer of playindicia circuit elements732A-732H. The presently preferred formulation for the ink used to print thefirst layer794 is given in Table 10.

  TABLE 10
  Ink Formulation for the First Layer 794
  (Opaque Blocking Layer 794)

  	material	wt %

  	Methyl Ethyl Ketone	56.13
  	VYHH vinyl resin	5.58
  	VMCA vinyl resin	17.00
  	Acrylic resin	3.28
  	Carbon Black	9.30
  	Diacetone alcohol	5.00
  	Sucrose acetate isobutyrate solution	2.50
  	polymeric surfactant	1.21

• The sheet resistivity of the ink described in Table 10 is greater than 20 MΩ/□.[0376]
• The next layer printed on the[0377]ticket700 contains theintegrity circuit elements740 as well as thedata circuit elements750A and750B. It will be recalled that theintegrity circuit elements740 are used to determine the authenticity and integrity of the ticket identification indicia, such as thebar code730, while thedata circuit elements750A and750B are used to provide additional ticket authenticity and integrity information. The ink used to print thedata circuit elements740 and thedata circuit elements750A and750B should be fairly conductive. The presently preferred formulation for the ink used to print thesecond layer816 containing theintegrity circuit elements740 and thedata circuit elements750A and750B is given in Table 11.

  TABLE 11
  Ink Formulation for the Second Layer 816
  (theIntegrity Circuit Elements 740 and
  theData Circuit Elements 750A and 750B)

  	material	wt %

  	Water	38.75
  	Styrenated acrylic Varnish (J678)	7.00
  	Dimethylethanol amine	0.25
  	Acetylenic surfactant	1.00
  	Defoamer (RS576)	0.25
  	Carbon Black	15.00
  	Stryrenated acrylic emulsion (7830)	21.75
  	Ethyl Alcohol	3.00
  	Styrenated acrylic emulsion (J89)	8.00
  	Polyethylene wax dispersion (J28)	5.00

• The ink formulation given in Table 11 has a sheet resistivity less than 5 KΩ/□.[0378]
• Both of the inks used to print the[0379]first layer794 and the second layer containing theintegrity circuit elements740 and thedata circuit elements750A and750B contain carbon black. Consequently, these two layers on theticket700 present a dark image. The third layer818 (shown in FIG. 58) is a masking layer which prevents visual interference from these two layers by masking thelower blocking layer794, theintegrity circuit elements740, and thedata circuit elements750A and750B. Thethird layer818 ideally is non-conductive relative to conductive layers, such as the layer ofintegrity circuit elements740 and the layer of playindicia circuit elements732A-732H. A suitable formulation for thethird layer818 was given previously in Table 7 and has a sheet resistivity greater than 10⁸Ω/□. The fourth layer printed on theticket700 is aprimer layer820 that provides a suitable surface for printing the play indicia720A-H (shown in FIG. 61). The ink used to print thefourth layer820 should be non-conductive relative to conductive layers, such as the layer ofintegrity circuit elements740 and the layer of playindicia circuit elements732A-732H and preferably has a sheet resistivity greater than 10⁸Ω/□.
• The fifth layer printed on the[0380]ticket700 contains the play indicia720A-720H (shown in FIG. 61). As will be recalled, a standard ink jet printing station is used to print this layer on theticket700. Consequently, this layer is printed with commercially available laser jet inks. The sixth layer826 (shown in FIG. 63) is a UV seal coat layer that protects the play indicia720A-720H and thevalidation number726 against abrasion. Thesixth layer826 should also be non-conductive relative to conductive layers, such as the layer ofintegrity circuit elements740 and the layer of playindicia circuit elements732A-732H and preferably has a sheet resistivity on the order of 10⁸Ω/□. The seventh layer printed on theticket700 is therelease coat layer828 which, as shown in FIG. 64, is printed asdiscreet layer portions828A-828H that are associated with the play indicia720A and thediscrete layer portion8281 that is associated with thevalidation number726. In order not to interfere with the electrical signatures of thecircuit elements732A-H,740,750A, and750B, the electrical conductivity of therelease coat layer828 should be significantly less than the electrical conductivity of thecircuit elements732A-H,740,750A, and750B and preferably has a sheet resistivity of 10⁸Ω/□.
• The eighth layer printed on the[0381]ticket700 is the opaque upper blocking layer830 (shown in FIG. 65) that helps to protect the play indicia720A-H, thevalidations number726 and portions of thecircuit elements732A-H,740,750A, and750B against surreptitious detection by candling. Theeighth layer830 preferably is non-conductive relative to the conductive layers on theticket700, such as the layer ofintegrity circuit elements740 anddata circuit elements750A and750B and the layer of playindicia circuit elements732A-732H. An appropriate formulation for the ink used to print the eighth layer (upper blocking layer830) is given in Table 12. This ink formulation has a sheet resistivity of greater than or equal to 20 MΩ/□. This formulation is preferred when the play indiciacircuit elements732A-732H are printed with the ink described in Table 13, below.

  TABLE 12
  Ink Formulation for the Eighth Layer 830
  (Upper Blocking Layer 830)

  	material	wt %

  	Conductive carbon black dispersion	30.00
  	(AGC 2708 Mod III, Merit)
  	Heptane	16.00
  	Normal propyl acetate	13.60
  	Kraton varnish (AGC 2640)	25.00
  	(a 25% solution of rubber copolymer)
  	Calcium Carbonate	10.00
  	PE/PTFE wax blend (PF 150)	3.00
  	Silicone Emulsion (DC 29)	0.50
  	Silicone Emulsion (DC 18)	0.90
  	Maleic rosin ester resin (3330 Varnish,	1.00
  	Merit)

• The play indicia[0382]circuit elements732A-732H (shown in FIG. 68) are printed on theticket700 as the ninth layer. The play indiciacircuit elements732A-732H are used to determine the authenticity and integrity of the play indicia720A-720H. Consequently, the ink used to print the play indiciacircuit elements732A-732H should be fairly conductive. An appropriate formulation for the ink used to print the play indiciacircuit elements732A-732H is given in Table 13. This formulation has a sheet resistivity of less than or equal to 2500 Ω/□ and is particulary useful when the document, such as theticket700, includes a stimatization element, such as an electronic fuse junction1146 (shown in FIG. 105 and described in more detail below.)

  TABLE 13
  Ink Formulation for the Ninth Layer
  (PlayIndicia Circuit Elements 732A-732H)

  	material	wt %

  	06-M conductive black base (Merit)	64.00
  	Colloid acrylic resin (Carboset 1594)	11.00
  	PE/PTFE wax blend (Polyfluo)	2.00
  	Ethanol	3.00
  	Acrylic microspheres (Ropaque OP 96)	5.00
  	Silicone emulsion (DC 29)	1.50
  	Surfactant (BYK 348)	0.50
  	Styrenated acrylic emulsion (Lucidene 604)	10.00
  	Water	3.00

• The tenth layer printed on the[0383]ticket700 is the removable scratch offcoating846, shown in FIG. 71. The scratch-off coating846 is printed as a continuous layer that covers theplay field portion706 of theticket700 and thevalidation number726 within theticket identification portion708 of the ticket. To avoid interference with the electrical signatures of thecircuit elements732A-H,740,750A, and750B, the electrical conductivity of the scratch-off coating846 should be significantly less that the electrical conductivity of thecircuit elements732A-H,740,750A, and750B and preferably has a sheet resistivity greater than 10⁸Ω/□. Suitable scratch-off coatings are well known in the art.
• The eleventh and twelfth layers printed on the[0384]ticket700 are overprint graphic layers, such as theplay spot areas716A-H, theplay spot graphics718, the void-if-removedarea722, and theoverprint graphics724. These layers help to provide the finished appearance of theticket700 as shown in FIG. 49. To avoid interference with the measured electric signatures of the conductive layers on theticket700, such as the second layer, which contains theintegrity circuit elements740 as well as thedata circuit elements750A and750B, and the ninth layer, which contains the play indiciacircuit elements732A-732H, these layers should be relatively non-conductive and preferably have sheet resistivities on the order of 10⁸Ω/□. Suitable overprint graphic inks are well known in the art.
• It can thus be seen that the electrical characteristics of the various layers vary from one layer to another, with some layers, such as[0385]second layer816 containing theintegrity circuit elements740 and thedata circuit elements750A and750B or the ninth layer containing the play indiciacircuit elements732A-732H, being relatively conductive while other layers, such as themasking layer818 or the UVseal coat layer826 are relatively non-conductive. The electrical characteristics of the layers printed on theticket700 in turn can affect the electrical signature measured by theelectronic verification machine1000. Table 14 summarizes the identity and electrical characteristics of the various layers printed on theticket700.

  TABLE 14
  Identity and Electrical Characteristics of
  Ticket 700 Printed Layers

  		Sheet
  Layer Number	Identity	Resistivity
  Layer
  12	Overprint Graphics	˜108Ω/□
  Layer 11	Overprint Graphics	˜108Ω/□
  Layer 10	RemovableScratch Off Coating 846	˜108Ω/□
  Layer 9	PlayIndicia Circuit Elements 732A-732H	≦2500 Ω/□
  Layer 8	OpaqueUpper Blocking Layer 830	≧20 MΩ/□
  Layer 7	Release Coat Layer 828	˜108Ω/□
  Layer 6	Seal Coat Layer 826	˜108Ω/□
  Layer 5	Play Indicia 720A-720H	˜108Ω/□
  Layer 4	Primer Layer 820	˜108Ω/□
  Layer 3	Masking Layer 818	˜108Ω/□
  Layer 2	Integrity Circuit Elements 740	<5000 Ω/□
  Layer 1	Opaque Blocking Layer 794	>20 MΩ/□

• Although the final form of the[0386]preferred embodiment ticket700 includes all of thelayers1 through12, specific portions of theticket700 may contain only a few of the layers because some of the layers are printed as discontinuous patterns or as discreet layer portions. For example, the ninth layer is composed of the individual playindicia circuit elements732A-732H and therefore is not a continuous layer. Similarly, therelease coat layer828 is printed asdiscreet layer portions828A-828H that are associated with the play indicia720A and thediscrete layer portion8281 that is associated with thevalidation number726. Consequently, there are several different printed layer patterns on theticket700, each of which can have different electrical signatures. Variations in the structure of theticket700 as described above might be desirable based on the configuration, use, or method of manufacture of such probability-type lottery tickets or similar documents utilizing conductive elements.
• The printing sequence described with reference to FIGS.[0387]49-77 results in at least three general types of printed layer patterns on theticket substrate702, as shown in FIGS.102A-104B. Referring to FIG. 102A, a first printedlayer pattern1140 consists of the firstopaque blocking layer794, the layer containing theintegrity circuit element740, themasking layer818, theprimer layer820, and the layer containing thebar code730. The first printedlayer pattern1140 is formed on the ticket identity portion708 (shown in FIG. 49) of theticket700. FIG. 102B is a conceptual representation of the two capacitors which are formed when theexcitation plate1130 and thesensor plate1132A are capacitively coupled to a portion of theticket700 which contains the first printedlayer pattern1140. The capacitive pick-uparea744 of theintegrity circuit element740 forms the conducting plane in theticket700 that couples with theexcitation plate1130 to form the first capacitor. The capacitive pick-uparea742 of theintegrity circuit element740 forms the conductive plane in theticket700 that couples with thesensor plate1132A to form the second capacitor. Theresistive element746 of theintegrity circuit element740 functions as the resistor that connects the two capacitors in series. Themasking layer818, theprimer layer820, and the layer containing thebar code730 serve as the insulating medium which is interposed between theexcitation plate1130 and the capacitive pick-uparea744 and which is interposed between thesensor plate1132A and the capacitive pick-uparea742. The thickness of themasking layer818, theprimer layer820, and the layer containing thebar code730 and the dielectric constant of themasking layer818, theprimer layer820, and the layer containing thebar code730 affect the magnitude of the capacitances C_t1and C_t2formed at theexcitation plate1130 and thesensor plate1132A.
• A second printed[0388]layer pattern1142, shown in FIG. 103A, consists of the firstopaque blocking layer794, themasking layer818, theprimer layer820, theseal coat layer826, theupper blocking layer830, and the scratch-off coating846. The second printedlayer pattern1142 is formed on theplaying field portion706 of theticket700 in locations where there are no play indicia, such as the portion of theticket700 between theplay spot area716B and theplay spot area716C (shown in FIG. 49). FIG. 103B is a conceptual representation of the two capacitors which are formed when theexcitation plate1130 and thesensor plate1132A are capacitively coupled to a portion of theticket700 which contains the second printedlayer pattern1142. Theupper blocking layer830 serves as both the conductive plane in theticket700 and the resistor which connects the two capacitors in series. The scratch-off coating846 and any overprint graphics serve as the insulating medium interposed between theexcitation plate1130 and theupper blocking layer830 and which is interposed between thesensor plate1132A and theupper blocking layer830. Consequently, the thickness of the scratch-off coating830 and any overprint graphics and the dielectric constant of the scratch-off layer830 and any overprint graphics affect the magnitude of the capacitances C_t1and C_t2formed at theexcitation plate1130 and thesensor plate1132A.
• A third printed[0389]layer pattern1144, shown in FIG. 104A, consists of theblocking layer794, themasking layer818, theprimer layer820, the layer containing the play indicia720A-720H, theseal coat layer826, therelease coat layer828, theupper blocking layer830, the layer containing theindicia circuit elements732A-732H, and the scratch-off coating846. The third printedlayer pattern1144 is formed on theplaying field706 portion of theticket700 at each of theplay spot areas716A-716H. FIG. 104B is a conceptual representation of the two capacitors which are formed when theexcitation plate1130 and thesensor plate1132A are capacitively coupled to a portion of theticket700 which contains the third printedlayer pattern1144. The capacitive pick-uparea736 of any givenindicia circuit element732A-732H forms the conducting plane in theticket700 that couples with theexcitation plate1130 to form the first capacitor. The capacitive pick-uparea734 of the given one of theindicia circuit elements732A-732H forms the conducting plane in theticket700 that couples with thesensor plate1132A to form the second capacitor. Theresistive element738 of the given one of theindicia circuit elements732A-732H serves as the resistor that connects the two capacitors in series. The scratch-off coating846 and any overprint graphics serve as the insulating medium interposed between theexcitation plate1130 and the capacitive pick-uparea736 and which is interposed between thesensor plate1132A and the capacitive pick-uparea734. Consequently, the thickness of the scratch-off coating830 and any overprint graphics and the dielectric constant of the scratch-off layer830 and any overprint graphics affect the magnitude of the capacitances C_t1and C_t2formed at theexcitation plate1130 and thesensor plate1132A.
• As stated earlier, there are thirteen sensed electrical values for each step of the[0390]stepper motor1058. Thestepper motor1058 advances the document being tested, such as theticket700, in discreet steps of 0.02 inches each. The number of scan rows for a given document, such as theticket700, can be determined by the following equation:
• Scan Rows=H/0.02 inches
• where H is the height of the document in inches. The thirteen electrical values for each step of the[0391]stepper motor1058 correspond to the C_totalacross each one of the thirteensensor plates1132A-1132M and theexcitation plate1130. C_totalbetween any given one of thesensor plates1132A-1132M, such as thesensor plate1132A, and theexcitation plate1130 in turn depends upon the nature of the printed layer patern, such as the printedlayer patterns1140,1142, and1144, that underlie thesensor plate1132A and theexcitation plate1130. Each step of thestepper motor1058 yields thirteen more electrical values, each of which can be different due to differences in the printed layer patterns which underlie each of the thirteensensor plates1132A-1132M. The resulting electrical signature is a two-dimensional array or grid, where the x-axis represents the 13 electrical values for each step of thestepper motor1058 and the y-axis represents the position of thesensor array1044 in stepper motor steps. The two dimensional array constitutes a scanned data map, such as the scanneddata map634 shown in FIG. 45, which represents the location and amount of conductive material on the tested document.
• When the document being tested is a probability game lottery ticket, such as the[0392]ticket700, the scanned data map, such as the map634 (FIG. 45), is compared to a game signature map, such as themap632 shown in FIG. 44, to determine the authenticity of the document. Theelectronic verification machine1000 downloads the game signature map from the central site computer via themodem1126 and stores the game signature map in thememory1116 of theprimary microcontroller1104. Each game signature map contains a series of vectors that define information about the sensed electrical values in a given area of theticket700. The area of the vectors is defined as a channel number (x-axis) by stepper motor steps (y-axis). The sensed electrical values are provided by the 8-bit A/D converter1112 in the support microcontroller1102. In the preferred embodiment of the invention, there are three general types of vectors: a Latex Vector, which corresponds to the electrical integrity of the printed layer patterns, such as thepatterns1140,1142, and1144, on theticket700; a Paper Vector, which is used to determine the thickness of the paper stock of theticket700 and to sense an object pushing the Latex Sensor off the paper substrate; and a Ghost Vector, which is used to provide protection against photocopies of theticket700.
• The software program that compares the scanned data map, such as the map[0393]634 (FIG. 45) with its associated game signature map, such as the map632 (FIG. 44) is called Electronic Latex Validation Software or ELVIS. ELVIS is stored in the flash memory portion of thememory1116 in theprimary microcontroller1104. After theticket700 has been successfully scamied by theelectronic verification machine1000, ELVIS is called to analyze the scanned data map of theticket700. ELVIS begins by extracting the first three digits of the bar code to determine the game number of theticket700. ELVIS uses the extracted game number to find the associated game signature map in the SRAM portion of thememory1116 of theprimary microcontroller1104. If there is no game signature map for the extracted game number, ELVIS aborts processing theticket700 and transmits a No Signature Map error message to thedisplay panel1012. The operator is then prompted to manually enter the three-digit security number of theticket700 via thenumeric keypad1018.
• Once ELVIS has retrieved a game signature map that corresponds to the document being tested, such as the[0394]ticket700, ELVIS then counts the total number of scan rows to determined the size of theticket700. If the ticket is found to be too big or too small, ELVIS aborts processing the ticket and transmits a Ticket Too Big/Small error message. However, if the size of theticket700 is acceptable, ELVIS then analyzes the three vector types for theticket700. The testing criteria used by ELVIS depends on the vector type. For Latex Vectors, Elvis first adds all latex vectors together to determine the total “Play area.” After the total “Play Area” is determined, ELVIS applies a minimum and maximum pixel count criteria to determine if the total “play area” is in compliance. Alternatively, in some circumstances a maximum pixel count alone can suffice. For Paper and Ghost Vectors, ELVIS will reject theticket700 if the testing criteria for either of these vectors is not met. ELVIS first analyses the Paper Vectors areas of theticket700 to determine if the signals are acceptable. Assuming that there are no Paper Vector errors, ELVIS will sum all of the Latex Vectors to determine the status of the printed layer patterns, such as thepatterns1140,1142, and1144, within theplay field portion706 of theticket700. If the Latex Vectors are found to be acceptable ELVIS examines the Ghost Vectors of theticket700 to determine if some of the removable scratch-off coating846 remains in any played portion of theticket700. If all of the above vector tests are passed, ELVIS concludes that theticket700 is authentic and has been validly played.
• C. Stigmatization[0395]
• In addition to measuring the electronic signature of the document being tested, the[0396]electronic verification machine1000 also can stigmatize the document. As explained earlier in Section VI., stigmatization refers to a process by which a document, such as theticket700, which has already been tested by theelectronic verification machine1000 is “marked.” In the case of game tickets, such as theticket700, stigmatization prevents winning tickets from being presented multiple times to be paid. A successful stigmatization scheme has several attributes. The stigmatization should be automatic: if human intervention is required to stigmatize the document errors can occur when the stigmatization is not done correctly. The stigmatization should also be difficult to circumvent. Preferably, the stigmatization equipment should require minimum maintenance. In addition, the stigmatization preferably permits monitoring of tested documents so that attempts at fraudulent redemption can be detected. Consequently, it is desirable that the stigmatization be difficult to detect.
• Currently accepted practices for stigmatizing a game ticket, such as the[0397]ticket700, include visually marking the ticket, for example by stamping the ticket with the words “PAID VOID”. Alternatively, it is common for winning tickets to be destroyed once they have been redeemed. However, since both of these stigmatization schemes require human intervention, the possibility exists that a winning ticket will not be stigmatized correctly and can then be presented multiple times for payoff. In addition, these stigmatization schemes do not permit monitoring of paid tickets so that attempts at fraudulent redemption can be detected. Another accepted practice is to maintain a paid ticket file in a central computer. Although such a scheme does not necessarily require human intervention and cannot be easily detected, such a stigmatization scheme requires that the ticket redemption terminal maintains a constant link with the central computer and such on-line linkages can be quite costly. As mentioned previously in Section IV., another method for stigmatizing a ticket involves automatically colorizing at least a portion of the ticket once it has been presented for redemption. For example, a portion of the document could be printed with an invisible ink that is thermally sensitive. Once the ticket is presented for redemption, power applied by the ticket terminal could be used to generate sufficient heat to change the color of the invisibly printed portion, thereby automatically stigmatizing the ticket. This scheme, however, has several disadvantages. The stigmatization is not difficult to detect, consequently this stigmatization scheme does not permit monitoring of paid tickets so that attempts at fraudulent redemption can be detected. Moreover, since heat is used as the method for activating the invisible ink and stigmatizing the ticket, heat sources other than the lottery terminal can inadvertently result in ticket stigmatization, for example, when the ticket is left in a closed car on a hot day.
• Referring back to FIG. 100, the[0398]fuse excitation pad1134, together with thesensor pad1132M of thesensor array1044 in theelectronic verification machine1000 can be used to electronically stigmatize a document, such as theticket700. Thefuse excitation pad1134 provides a high voltage excitation signal which is used to alter the state of a printed circuit element on the document. An example of a printed circuit element that can be electronically altered by theelectronic verification machine1000 is shown in FIG. 105, where the printed circuit element is an electronic fuse junction or fuse1146. The electronic fuse junction1146 includes an excitation pick-uparea1148 and a sensor pick-uparea1150 connected by afuse link1152. As explained in more detail below, theelectronic verification machine1000 provides sufficient energy to the electronic fuse junction1146 via the fuse excitation pad1134 (shown in FIG. 100) to open thefuse link1152 between the excitation pick-uparea1148 and the sensor pick-uparea1150. As described in detail below, direct measurement circuitry in theelectronic verification machine1000 has the capability of checking the state of the electronic fuse junction1146. An open electronic fuse junction1146, where thefuse link1152 is not present, normally indicates that the document has already been tested by theelectronic verification machine1000. On the other hand, a closed electronic fuse junction1146 indicates that the document has not been previously tested by theelectronic verification machine1000.
• An important feature of the electronic fuse junction[0399]1146 is that it changes its binary status, from closed to open, when theelectronic verification machine1000 applies an energy pulse via thefuse excitation pad1134. Therefore the composition and configuration of the electronic fuse junction1146 is selected such that the electronic fuse junction1146 changes its binary status upon receipt of the energy pulse rather than simply absorbing the energy pulse through, for example, heat transfer to the substrate or other materials on the document. It is desirable to make the time duration of the energy pulse provided by theelectronic verification machine1000 as short as possible, for example, on the order of 0.1 seconds. By the same token, to minimize heat transfer to the ambient surroundings thefuse link1152 should be as small as possible. In addition, the electronic fuse junction1146, including thefuse link1152, preferably is formed from a material that has a reasonably high resistance so that the current flow through thefuse link1152 will generate enough heat to break the conductive path.
• When the electronic fuse junction[0400]1146 is printed on probability game tickets, such as theticket700, there are additional attributes that the electronic fuse junction1146 should have. For example, the electronic fuse junction1146 should be formed from a material that is not hazardous to the environment or to humans. The electronic fuse junction1146 also should be formed from a material that can be printed with a Gravure, Offset, or Lithograph printing press. It is also desirable that the electronic fuse junction1146 should be formed from a material which is already being used on theticket700, to avoid having to add an additional printing station.
• In one example, the electronic fuse junction[0401]1146 is printed on the document using an ink that has a sheet resistivity in a range of from about 800 Ω/□ to about 2.4 KΩ/□. Preferably, the ink used to print the electronic fuse junction1146 has a sheet resistivity on the order of 2.4 KΩ/□. Along with the above discussed criteria, the dimensions of thefuse link1152 are determined by a number of additional factors, including by the printing press resolution, the characteristics of the ink used to print the electronic fuse junction1146, the dimensions of thesensor plates1132A-1132M in thesensor array1044, and the characteristics of the substrate on which the electronic fuse junction1146 is printed. In the example of the electronic fuse junction1146 printed on a probability game ticket, such as theticket700, the vertical dimension of the excitation pick-uparea1148 preferably is about 0.24 inches, as is the vertical dimension of the sensor pick-uparea1150. The horizontal dimension of the excitation pick-uparea1148 preferably is about 0.10 inches, as is the horizontal dimension of the sensor pick-uparea1150. The vertical dimension of thefuse link1152 preferably is about 0.02 inches and the horizontal dimension of thefuse link1152 preferably is about 0.05 inches. In addition, when the electronic fuse junction1146 is printed on a probability game ticket, such as theticket700, the electronic fuse junction1146 can be printed on theticket700 with the same ink used to print the play indiciacircuit elements732A-732H (shown in FIG. 50). Therefore, an additional printing station is not needed to print the electronic fuse junction1146 on theticket700. When the electronic fuse junction1146 is printed with an ink that has a sheet resistivity of 2.4 KΩ/□, for example, the ink formulation desribed in Table 13, and has the aforementioned preferred dimension thefuse link1152 has a resistance between 6 KΩ and 16 KΩ that opens reliably with the application of 0.1 joules of energy expended in 0.1 second or less. It should also be pointed out that the electronic fuse junction1146 can be printed with the same ink used to print the circuit elements on theprobability game ticket700 or with the upper conductive black ink on a conventional lottery ticket.
• The functional block diagram of FIG. 106 illustrates the[0402]stigmatization circuit1096 that can be used to stigmatize a document such as theprobability ticket700 having the electronic fuse junction1146 of the type shown in FIG. 105. As indicated above, it has been found that the application of 0.1 joules of energy to the electronic fuse junction1146 in approximately 0.01 seconds is enough to reliably open thefuse link1152. To expend 0.1 joules in 0.01 seconds requires 10 watts of average power. Power in a resistor is equal to the product of the resistance and the square of the current through it. For a 16,000 Ω resistor such as thefuse link1152, the required current is:
• (10/16000)^1/2=25 mA
• The voltage across a resistor is equal to the product of the resistance and the current through it. In this example, the required voltage is then:[0403]
• 16000×0.025=400 volts
• Thus it is possible to open a 16 KΩ fuse junction by applying 400 volts DC to the junction. Most 10-watt, 400-volt supplies, however, are large and expensive. However, storing the energy in a capacitor, such as a capacitor C[0404]1 as shown in FIG. 106, over a relatively long time period, at a relatively low charging rate, and discharging the capacitor into the electronic fuse junction1146 quickly can substantially reduce the size and cost of the supply. The energy stored in a capacitor is equal to:
• Energy stored in cap.=½CE²joules
• Solving for C,[0405]
• C=(2E)/V²
• With E=0.1 joules and V=400 volts, C[0406]_min=1.25 μF. Since 1 μF capacitors are more available than 1.25 μF capacitors, the above formula suggests the use of a voltage V of at least 470 volts. With a voltage V of 500 volts the total capacitor energy will be 0.125 joules. In this case, it will take approximately 13 ms to apply 0.1 joules of energy into thefuse link1152 which is significantly below the desired 100 ms indicated above.
• It is possible to provide a 500 voltage supply that runs continuously or a voltage supply that turns on when the leading edge of a ticket passes the first edge detector. The advantage to having the voltage supply constantly operating is that the electronic fuse junction[0407]1146 could be located anywhere on theticket700, including the leading edge. On the other hand, if the voltage supply is off until needed, the electronic fuse junction1146 should be located near the end of the ticket to allow the storage capacitor time to be charged. Assuming thetickets700 are fed into themachine1000 one after the other, the supply should be able to recover in the time required to process a 2-inch long ticket. Given that the stepper motor moves theticket700 at 0.02-inch per step at approximately 300 steps per second, 0.5 seconds is available to charge the capacitor C1. Where the capacitor C1 is charged with a constant current and the actual values are V equal to 500 volts and C1 equal to 1 μF, total capacitor energy will be 0.125 joules. Approximately 13 ms are required to dump 0.1 joules into the 16,000Ω resistor1152. This time is well below 100 ms. Also since:
• I=C(dv/dt)
• I=(0.5)(1.0×10⁻⁶)/0.5=1 mA
• The maximum output power from the supply is thus:[0408]
• P=IV
• P=500×0.001=0.5 watts
• which is 20 times smaller than the 10-watt power supply mentioned above.[0409]
• It should be understood that voltage converter topology presents a variety of choices. It is possible to use a push-pull converter, boost converter, or flyback converter. In this case, there is no particular advantage to transformer isolation and the output power is low enough to make push-pull unnecessary. In order to reduce the cost of the voltage supply, a simple boost power supply using a Texas Instruments (TI)[0410]TL497 controller1154, an off-the-shelf inductor, and 1 μF storage capacitor C1 are used in the preferred embodiment of the invention shown in FIG. 106. Thesupply1154 normally will require 0.3 seconds to produce 500 volts on the capacitor C1.
• Operation of the[0411]stigmatization circuit1096 shown in FIG. 106 will now be described in connection with the operation of theelectronic verification machine1000. Thesupply1154 is activated by a signal (from the support microcontroller1102) on an inhibitline1156 which converts a 12 volt DC voltage on aline1158 from the system power supply (not shown) to a500 volt voltage on aninput line1160 to the capacitor C1. The electronic fuse junction1146 is moved by thestepper motor1058 into position between thefuse excitation plate1134 and thesensor pad1132M. A voltage divider including a resistor R3 and thefuse link1152 along with a diode D1 respond to a 5 volt signal on aline1162, from the system power supply (not shown), to apply a voltage on alink monitor line1164 which in turn is input to an analog to digital converter (not shown) on the support microcontroller1102. In the event that thefuse link1152 is open, indicating that theticket700 might have already been stigmatized, a voltage of 5 volts will appear on thelink monitor line1164. On the other hand, if thefuse link1152 is still present and ignoring the resistance in thefuse link1152 and the resistor R3, a small voltage, for example 0.6 volts will appear on thelink monitor line1164 due to the resistance in the diode D1 and a diode D2. However, if the resistor R3 has a value equal to the value of thefuse link1152 resistance, for example 16,000K Ω, then the voltage on thelink monitor line1164 will be about 2.8 volts. One advantage of the invention is that by printing thefuse link1152 with a known value, it is possible to significantly reduce the possibility of counterfeits by in effect measuring the resistance value of thefuse link1152.
• In one embodiment of the invention, once the value of the resistance of the[0412]fuse link1152 is determined, the voltage of the output of thepower supply1154 can be measured using a voltage divider including a pair of resistors R1 and R2. The output of this voltage divider is applied over a highvoltage monitor line1166 to the analog to digital converter (not shown) on the support microcontroller1102. In this manner it is possible for the support microcontroller1102 to determine if there is sufficient charge on the capacitor C1 to blow thefuse link1152. When the voltage on the capacitor C1 has reached a predetermined value, such as 470 volts, this voltage is applied to thefuse link1152 via a switch SW1 and over thefuse excitation plate1134 and thesensor pad1132M. The switch SW1 can be a field effect transistor under control of the support microcontroller1102 via aline1166. It should be noted that the diode D1 serves to protect thelink monitor line1164 from the high voltage on the capacitor C1. Also, in thiscircuit1096, the diode D2 prevents the current in thefuse link1152 from pulling thepad1132M to more than 0.7 volts above ground.
• One of the advantages of the[0413]circuit1096 shown in FIG. 106 is that theplate1132M can be used as both a sensor plate for sensing the various criteria in theticket700 as described above and as ground plate for stigmatizing theticket700. Here a switch SW2, which also can be a field effect transistor, is switched on at the same time the switch SW1 is closed in response to the stigmatization signal on theline1166. This prevents the current in thefuse link1152 from returning to the sensor excitation circuit.
• In the preferred embodiment, after the stigmatization voltage has been applied from capacitor C[0414]1 to the electronic fuse junction1146, the switches SW1 and SW2 are opened and the support microprocessor1102 measures the voltage on thelink monitor line1164. If the voltage on this line is 5 volts, indicating that thefuse link1152 might have been blown, theticket700 is advanced by thestepper motor1058 one step or 0.02 inches. The support microcontroller1102 again measures the voltage on thelink monitor line1164 and if the voltage is significantly below 5 volts, the stigmatization process is initiated again. After five such steps without a significant drop in the voltage on thelink monitor line1164, it is assumed that thefuse link1152 has been successfully blown. At this point, the stigmatization process has been completed and the highvoltage power supply1154 is inhibited by a signal online1156. One advantage of using an electronic fuse junction having dimensions larger than theexcitation plate1134 and thesensor plate1132M, is that it is possible to test thefuse link1152 over a number of steps to ensure that it has been opened.
• The following is the preferred criteria for using the circuit such as the[0415]circuit1096 in theelectronic validation machine1000 to stigmatize lottery tickets. Losing tickets can be stigmatized although there is no apparent advantage to doing so. Conversely, it is not apparent that there is any particular disadvantage to stigmatizing a losing ticket. Therefore, losing tickets will be stigmatized. Winning tickets should be stigmatized. In the event of a barcode misread, the ticket preferably should not be stigmatized. Theelectronic validation machine1000 should back the ticket out and request a rescan. The ticket may have been inserted backward or upside down.
• With respect to improperly played tickets, the general conclusion is to stigmatize all of them. Regarding counterfeit tickets and tickets that have been tampered with, as detected by measuring the electrical properties of the[0416]fuse link1152 as described above, the ticket should not be stigmatized. Rather the ticket should be retained by the lottery agent and submitted for analysis.
• D. Document Thickness Measurement[0417]
• FIG. 107 illustrates another significant feature of the[0418]electronic validation machine1000 which is the capability of measuring the thickness t of the substrate of a lottery ticket and similar type documents. This feature will be described in connection with thelottery ticket700.
• As discussed above, the primary electrical signature value that the[0419]electronic validation machine1000 utilizes is capacitance. Factors influencing capacitance listed below:
• C=Kε₀(A/t)
• where:[0420]
• C=Capacitance (in Farads)[0421]
• K=Dielectric Constant[0422]
• A=Area of Electrodes (inches[0423]²)
• t=Electrode Spacing−dielectric thickness (inches)[0424]
• ε[0425]₀=Constant−0.225 Farad/inch
• When there are no conductive or semiconductive ink films located beneath the[0426]sensor head1036 shown in FIG. 100, the electrical waves produced by theexcitation bus bar576 will penetrate through the substrate of the document such asticket700 and appear to reflect off of thepressure roller1056 as indicated by a pair ofarrows1168 and1170. Also, it should be noted that it is desirable that the pressure roller be insulated from ground to achieve this reflection effect. The reflected signal is absorbed by thechannel sense capacitors1132A-1132M and can be processed as an electrical signature for the ticket's paper stock byelectronic validation machine1000 as described above. Thus,electronic validation machine1000 can evaluate the thickness (t) of a ticket's paper substrate as well as the composition (K) of the substrate. For the frequency range of the electrical illuminating signal used inelectronic validation machine1000 as indicated above, the dielectric constant of typical paper stock (K_p) will range between:
• K_p: 3.29≦K_p≦4.8
• As a practical matter this relative small dielectric range (1.51) for ticket paper substrates in itself has minimal impact on ticket security determination in this particular example. However, evaluation of the thickness t of the substrate can be very important to lottery ticket security. The[0427]electronic validation machine1000 will normally read a lottery ticket's barcode to determine if theticket700 has winning indicia printed under its scratch-off latex. On a traditional scratch-off lottery ticket, the barcode is almost always printed on the back of the ticket. Therefore, it is possible to defraud the lottery by securing an unplayed ticket behind a properly played ticket and feeding both ticket through theelectronic validation machine1000 assuming that theelectronic validation machine1000 will scan the latex of the front ticket and the barcode on the back of the ticket.
• However, by measuring the thickness t of the[0428]substrate702 of thelottery ticket700 at the trailing edge of the ticket where no conductive materials are located, it is possible to determine if additional material such as another ticket has been added to the ticket undergoing validation. As illustrated in FIG. 107, when scanning non-latex areas of a scratch-off theticket700, thepaper substrate702 functions as a large part of the coupling capacitor's dielectric. Because both the thickness (t) and dielectric constant (K) of a capacitor's dielectric affect the coupling capacitance and because the dielectric constant for a ticket's paper substrate (K_p4767) does not vary over a significant range and because the capacitance C is divided by the thickness (t) of the dielectric of the coupling capacitor increasing the influence of the dielectric's thickness (t) on the sensed coupling capacitance, theelectronic validation machine1000 can easily detect an additional ticket between thefront ticket700 and thepressure roller1056. For example, the coupling capacitance sensed by theelectronic validation machine1000 for a single 10 point (0.01 inch) ticket substrate would be approximately:
• C=Kε₀(A/t)
• C=4ε₀(0.1/0.01)
• C=40ε₀
• As a result, the coupling capacitance sensed by the[0429]electronic validation machine1000 for a ticket having a substrate double the thickness of thesubstrate702 of thelottery ticket700 would be one-half of the value measured for a single ticket:
• C=4ε₀(0.01/(2×0.01))
• C=20ε₀
• Thus, the change in the sensed capacitance C and therefore a difference in the thickness (t) is readily detectable by the[0430]electronic validation machine1000.
• The composition of the[0431]pressure roller1056 is important in making it electrically reflective. For example, if thepressure roller1056 is made out of a typical rubber compound with carbon particles embedded in the rubber, the direct current (dc) resistivity of the pressure roller (ρ_roller) has a very high value:
• ρ_roller>2MΩ/cm
• This is not surprising because this roller is primarily made of a rubber binder surrounding numerous carbon particles. Rubber is a commonly used insulator and has a very high dc resistivity:[0432]
• ρ_rubber: 8×10¹²≦ρ_rubber≦2×10¹⁵Ω/cm
• Carbon, on the other hand has a relatively low resistivity (ρ[0433]_carbon):
• ρ_carbon≈35 KΩ/cm
• This composite roller has a very high dc resistivity because its numerous carbon particles are encapsulated in the high resistivity rubber binder. Therefore, there is no low resistance dc path from one carbon particle to another.[0434]
• However, this arrangement of carbon particles encapsulated by very thin films of rubber (micron level) causes the composite roller to exhibit a very high dielectric constant, K[0435]_roller>>300. Apparently due to the close proximity of conductive carbon particles insulated by thin films of rubber which create a 3-dimensional network comprised of a large number of capacitors. Thus, the network consists of numerous microscopic capacitors in a complex arrangement of series and parallel Resistance Capacitance (RC) circuits.
• For the excitation frequency range used in the[0436]electronic validation machine1000, the dielectric constant of rubber compounds, excluding polysulfide rubber (K=2260), ranges from a low of 2.38 (Butyl rubber) to a high of 6.60 (Neoprene rubber). Assuming a rubber dielectric of K=6.60 (for neoprene,) the capacitance between the carbon particles would not be large unless the thickness of the dielectric is very small. Preferably, the best way to obtain small dielectric spacing is with high carbon loading, that is the percentage of carbon particles relative to rubber binder contained in the composite roller material. By increasing the percentage of carbon particles relative to rubber binder the spacing between the individual carbon particles will be reduced. Thus, it is believed that the very small spacing between the conductive carbon particles causes the pressure roller to effectively exhibit an extremely high dielectric constant. As a result, the preferred composition of thepressure roller1056 is a nonconductive elastomeric material, such as rubber, encapsulating a large number of conductive particles, such as carbon.
• XIII. Other Applications Of The Invention[0437]
• The present invention is not limited to validating or determining the authenticity and integrity of probability game, pull-tab or other types of lottery tickets, but is applicable in many circumstances in which bar code readers and magnetic stripes are used. For example a document such as a stock certificate could be printed with electronic circuits similar to the resistors[0438]82-96 printed on thelottery ticket50 where the electrical signatures of the circuits represent verification data such as a serial number. Human readable document data such as the serial number would also be printed on the stock certificate. Theelectronic verification machine108 or500 would then electrically couple with the circuit elements as described above to generate a verification signal representing the electrical signatures and hence the verification data. Authentication of the certificate is then accomplished by theprocessor board220 or terminal532 which relates or compares the verification signal to a data signal representing the document data. The data signal can be generated by an optical character reader or a user interface such as thekeyboard178. In this manner the electronic document machine can verify that the serial number printed on the certificate is the correct one for the certificate and thus authenticate the document.
• It will then be appreciated that the present invention will have utility in a variety of areas including coupon redemption, inventory security, airport tracking systems, magnetic stripes, currency security, compact disk security, drivers license and passport security. Coupon fraud is a serious problem for the retail industry. Current estimates of money lost to coupon fraud range in the hundreds of millions of dollars. Moreover, with the advent and growth of desk-top publishing and color-photocopiers, the opportunities for coupon fraud as well as other types of document fraud will increase. The present invention can be used to stem the growth of coupon fraud. Providing coupons with an electrical signature by printing at least a portion of an electric circuit on the coupons, according to the invention, would provide the ability to verify the authenticity of the coupons submitted for payment. Further, by utilizing the stigmatizing technique described above it will be possible to prevent coupons from being redeemed more than once. As to inventory security, the circuits according to the present invention can be printed directly on an inventory ticket, price tag or manufacturer's tag thus supplanting the use of metal strips and coils. Airline ticket fraud, which may also cost hundreds of millions of dollars annually, present another application for the present invention. Circuits according to the present invention could be used to ensure the authenticity and integrity of airline tickets. In addition, the present invention could be used to track the luggage associated with airline travel. The present invention can also be used as an effective alternative to magnetic stripes. Magnetic stripes contain identification numbers, for example, credit card numbers, that are programmed at manufacture. The stripes are prone to failure and are subject to fraud because they are easily copied or modified. To overcome these shortcomings, circuits according to the present invention could be printed on a substrate and encoded with specific customer information. Thus the present invention can be used to improve the security of credit cards, automatic teller machine (“ATM”) cards, and any other tracking card which uses magnetic stripes as a security measure. The present invention can also be used to mitigate the losses resulting from currency fraud which includes, for example, counterfeit currency, and check forgery. Counterfeiting of these documents could be reduced if the documents were provided with an electrical signature or conductive fibers as described above. The invention could be used in the same manner to improve the security of drivers licenses and passports. The invention could also be used to provide inventory control of compact disks which, because of their small size, are subject to theft. Circuits according to the present invention, which included RF devices, could be used to track the compact disks and to prevent their clandestine removal.[0439]
• Although the present invention has been described with reference to preferred embodiments, it will be understood that various changes and modifications will be suggested to one skilled in the art and it is intended that the invention encompass such changes and modifications as fall within the scope of the appended claims.[0440]

Claims (20)

We claim:

1. A method for forming a document, comprising the steps of:

selecting a marking medium having a pre-determined machine-readable characteristic;

selecting a document substrate compatible with said pre-determined machine-readable characteristic;

securing an information symbol to said document substrate; and

affixing a security layer including said marking medium to said document substrate in at least partial register with said information symbol.

2. The method ofclaim 1 wherein said document substrate is substantially non-rigid.

3. The method ofclaim 1 wherein said information symbol is intermediate said document substrate and said security layer.

4. The method ofclaim 1 further including the step of affixing a blocking layer to said document substrate in at least partial register with said information symbol.

5. The method ofclaim 4 wherein said blocking layer is intermediate said information symbol and said security layer.

6. The method ofclaim 4 wherein said security layer is intermediate said information symbol and said blocking layer.

7. The method ofclaim 4 wherein said pre-determined machine-readable characteristic is electrical conductivity and wherein said marking medium is an ink having a dry-state sheet resistivity in a range of from about 1 KΩ/□ to about 5 KΩ/□.

8. The method ofclaim 7 wherein said blocking layer is substantially non-conductive.

9. A method for forming a document, comprising the steps of;

selecting a first marking medium having a first pre-determined machine-readable characteristic;

selecting a second marking medium having a second pre-determined machine-readable characteristic;

selecting a document substrate compatible with said first and second pre-determined machine-readable characteristics;

apportioning said document substrate into at least a first portion and a second portion;

securing a first information symbol to said document substrate within said first portion;

securing a second information symbol to said document substrate within said second portion; and

affixing a first security layer including said first marking medium to said first portion of said document substrate in at least partial register with said first information symbol.

10. The method ofclaim 9 further including the step of affixing a blocking layer to said document substrate in at least partial register with said first information symbol.

11. The method ofclaim 10 wherein said blocking layer is intermediate said first information symbol and said security layer.

12. The method ofclaim 10 wherein said security layer is intermediate said first information symbol and said security layer.

13. The method ofclaim 9 further including the step of affixing a second security layer including said second marking medium to said second portion of said document substrate in at least partial register with said second information symbol.

14. The method ofclaim 13 wherein said first pre-determined machine-readable characteristic is electrical conductivity and wherein said first marking medium is an ink having a dry-state sheet resistivity in a range of from about 1 KΩ/□ to about 5 KΩ/□.

15. The method ofclaim 14 wherein said second pre-determined machine-readable characteristic is electrical conductivity and wherein said second marking medium is an ink having a dry-state sheet resistivity in a range of from about 1KΩ/□ to about 5 KΩ/□.

16. The method ofclaim 14 further including the step of securing a substantially non-conductive blocking layer to said document substrate in at least partial register with said first information symbol.

17. A method for forming a lottery ticket, comprising the steps of;

selecting a first marking medium having a first pre-determined machine-readable characteristic;

selecting a second marking medium having a second pre-determined machine-readable characteristic;

selecting a substantially non-rigid ticket substrate compatible with said first and second pre-determined machine-readable characteristics;

apportioning said ticket substrate into at least a first portion and a second portion;

printing a play symbol over said ticket substrate within said first portion;

printing a bar code over said ticket substrate within said second portion; and

affixing a first security layer including said first marking medium to said first portion of said ticket substrate in at least partial register with said play symbol, said play symbol being intermediate said ticket substrate and said first security layer, said first security layer being removable by a player from said ticket substrate.

18. The method ofclaim 17 further including the step of securing a second security layer including said second marking medium to said second portion of said ticket substrate in at least partial register with said bar code, said second security layer being intermediate said ticket substrate and said bar code.

19. The method ofclaim 17 wherein said first pre-determined machine-readable characteristic is electrical conductivity and wherein said first marking medium is an ink having a dry-state sheet resistivity in a range of from about 1 KΩ/□ to about 2.5 KΩ/□.

20. The method ofclaim 19 wherein said ink includes a weight percentage of conductive carbon in a range of from about 13% to about 64%.

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