US3868057A - Credit card and indentity verification system - Google Patents

Abstract

An improved form of credit or identification card and a system for verifying the propriety of ownership thereof. The card comprises, in addition to the conventional embossed indicia which ordinarily includes a name and an account number, a laminated or encapsulated center layer of material upon which is deposited an electrical circuit consisting of a matrix of electrical conductors and semiconductors coupled to a plurality of contact points. At least three of the contact points are coupled to certain ones of the semiconductor devices thereby providing a code number unique to each card and the remaining contacts are coupled to other parts of the circuit to give a false code. A card verifier has a like plurality of electrical contacts adapted to engage the card contacts and a plurality of selectors for selectively coupling the circuit in the card with a circuit in the verifier so as to produce a YES or NO output signal to verify selection of the proper code number.

Description

ist-aeeioail United St 1 Chavez 1 1 CREDIT CARD AND INDENTITY VERIFICATION SYSTEM [76] Inventor: Robert C. Chavez, 1764 Industrial Rd., Las Vegas, Nev. 89102 [22] Filed: June 4, 1973 [21] Appl. No.: 366,762

Related U.S. Application Data [63] Continuation-in-part of Ser. No. 157,928, June 29,

1971, abandoned.

52 us. c1. ..235/61.7B,235/61.11A,

7., 5/ N. 49/149 A 51 1m.c1 ..G06k 5/00,GO6k 7/O6,G06k 19/06 [58] Field ofSearch ,..235/61.7 B, 61.11 A, 61.11 C,

[ Feb. 25, 1975 FOREIGN PATENTS OR APPLICATIONS 851,357 9/1970Canada 235/617 B Primary ExaminerDaryl W. Cook Attorney, Agent, or Firm& Lyon Lyon [57] ABSTRACT An improved form of credit or identification card and a system for verifying the propriety of ownership thereof. The card comprises, in addition to the conventional embossed indicia which ordinarily includes a name and an account number, a laminated or encapsulated center layer of material upon which is deposited an electrical circuit consisting of a matrix of electrical conductors and semiconductors coupled to a plurality of contact points. At least three of the contact points are coupled to certain ones of the semiconductor devices thereby providing a code number unique to each card and the remaining contacts are coupled to other parts of the circuit to give a false code. A card verifier has a like plurality of electrical contacts adapted to engage the card contacts and a plurality of selectors for selectively coupling the circuit in the card with a circuit in the verifier so as to produce a YES or NO output signal to verify selection of the proper code number.

19 Claims, 10 Drawing FiguresPAIENIEE I975 3. 868 057 am 1 ord Q R 2W W 0 w w /W F E w E CREDIT CARD AND INDENTITY VERIFICATION SYSTEM This is a continuation-in-part of my previous application, Ser. No. 157,928 filed June 29, 1971, now abandoned.

BACKGROUND OF TI-IE INVENTION The present invention relates generally to a credit card system which makes possible the virtual elimination of credit card misuse. The ensuing description deals with the use of the invention as a credit card, although it will be apparent that potential scope of the invention would include any use as a positive means of identification. The advent of credit cards for the convenient acquisition of goods and services in lieu of the use of currency has carried with it considerable problems in what may be generally called credit card misuse. Misuse of credit cards includes the use by others of cards which have been either lost or stolen, unpremediated felonious users who have received unsolicited credit cards in the mail, but who deny having used them, outright counterfeiting of credit cards, and the use of cards by the rightful owner thereof beyond the agreed credit limits. In such cases, substantial financial liability may be borne by either the credit card holder, the credit card company or both, and recent reports have indicated that losses sustained on account of credit card misuse total in the hundreds of millions of dollars annually. It is submitted that such losses are sustained as a direct result of the fact that credit card misuse is relatively easy to commit by those persons so disposed because of the lack of a positive and easy means of identification.

Most credit cards currently in use have a place for the signature of the authorized user but this proper signature is seldom, if ever, checked or compared with the actual users signature because the clerks handling an individual transaction are not competent to analyze the handwriting. Other credit cards currently in use have a picture of the authorized user but again this is not a positive means of identification, it is an inconvenience when the rightful user desires to permit another to use his card, and it certainly does not prevent counterfeiting. Other methods of positive identification have been proposed, such as a fingerprint check or a magnetically-encoded strip of material on the card which can be read by an appropriate card-reading device but these systems are very costly to implement.

SUMMARY OF THE INVENTION The foregoing shortcomings may be eliminated through the use of the present invention inasmuch as the credit card herein proposed is provided with a secret code number which shall be known only to the rightful user thereof. When the holder of the credit card desires to use it, it is inserted in a verification device and the rightful user thereof selects by means of appropriate control on the verification device the code number known only to him and when he selects the proper series of numbers, there will be a visual indication that the number encoded on the card corresponds with the number selected by the card user. Obviously, not knowing the proper number, one who finds or steals the card will not be able to use it. The manner in which the code number is encoded on the card makes it extremely difficult to ascertain the correct code number.

In one embodiment the credit card containsa matrix of contact points, ideally a hundred or more and each contact point can then be assigned a code according to a numerical or alpha-numerical system. Each of the contact points is interconnected with the other by thin deposits of electrical conducting material but rather than being directly connected to one another each of the points is electrically connected to a small deposit of semiconductor material which in the form of diode provides a finite electrical resistance between any two points. Three or more of these contact points are not interconnected in the mannerjust described but in turn are electrically connected to a semiconductor device having three or more terminals, such as a transistor. The contact points which are connected to the semiconductor device are selected at random in the matrix.

It is these three or more points which determine the unique code number for the individual card, as deter mined by the coding system. I

The card verification device contains a plurality of sensing devices adapted to contact the contact points on the card when the card is inserted in the device. The verification device also contains a number of selectors by which the card user selects the contact points corresponding to the code or index number so that the device electrically connects to the three or more terminals which communicate with the semiconductor device. By this method, the semiconductor device is coupled to a circuit in the verification device so that an electrical circuit is completed whereby current will be conducted to indicate a proper selection of code num bers. If the incorrect number is selected, the circuit within the verification device will not be properly completed and an error signal will result. The interconnection of all of the unused contact points through semiconductor material renders it extremely difficult to ascertain the proper code number inasmuch as resistance measurements made upon the card using an ohmmeter, for example, will provide confusingly false readings between any two contact points whether the meter is attached to the proper contact points or not. Thus, resistance measurements made upon all of the contact points trying all of the various combinations will not permit a wrongful possessor of the card to determine the proper code number.

In a modified form of the invention a unique coding circuit employing a series of SCRs is embedded in the card and due to the configuration ofthis circuit the number of contact points on the card, and therefore in the verifier as well, is reduced to a small number. This circuit still provides a very large number of possible combinations while also providing false code indications if effort is made to decode the same.

It is an object therefore of the present invention to provide a credit card and a credit card verification device whereby improper use can be substantially eliminated.

It is also an object of the present invention to provide an improved credit card system whereby the proper owner of a credit card may utilize it without fear of financial liability on account of loss or theft and in addition permitting the credit card company to utilize the card verification device for accounting purposes.

It is a further object of the invention to provide a credit card verification system which will substantially facilitate the recovery of lost or stolen cards.

Further objects and advantages of the present inven tion will be readily apparent upon reading the ensuing detailed description in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial representation of a form of a credit card verification device showing a credit card in association therewith.

FIG. 2 is an exploded perspective view of a credit card made in accordance with one embodiment of the present invention.

FIG. 3 is an enlarged sectional view showing the relationship of the credit card verifier and the credit card.

FIG. 4 is an enlarged plan view of one embodiment of the intermediate layer showing the matrix arrangement and semiconductors thereon.

FIG. 5 is a circuit diagram of one embodiment of the electrical portion of the credit card verifying device.

FIG. 6 is a plan view of the intermediate layer of the card showing another embodiment thereof employing a NAND gate.

FIG. 7 is another circuit diagram for an alternative electrical portion of the card verifier.

FIG. 8 is the equivalent circuit for the NAND gate employed in FIG. 6.

FIGS. 9a and 9b are circuit diagrams of another embodiment of the present invention showing an improved and simplified coding circuit for the card in FIG. 9a and a simplified code selection and verification circuit in FIG. 9b.

DESCRIPTION OF THE FIRST EMBODIMENT As shown in FIG. 1, the new credit card generally designated 10 comprises three initially separate layers of material which are subsequently permanently bonded together. As is the current practice, the materials used in the three separate layers may be any suitable, somewhat rigid plastic. Thetop layer 12 would have the same general appearance as do most credit cards today including thename 13 of the credit card holder, hisaccount number 14 and an insignia or name indicating the credit card company as represented by thedesign 15. Thename 13 and theaccount number 14 are ordinarily embossed on the surface of the card and provide a means for imprinting the name and account numberon invoices. When constructed in this manner, the credit card of the present invention is compatible with credit card imprinting devices currently in use but it is contemplated that the credit card verification device disclosed herein may also incorporate the details of credit card invoice printing devices although it is not deemed necessary to show the details of such construction inasmuch as they are well known in the art.

The bottom layer of thecard 16 is a substantially flat member with no raised or embossed indicia thereon but is provided with a plurality of spacedapertures 18 which are symmetrically located over the entire surface of thebottom layer 16 in a grid or matrix fashion defin ing a system of coordinates. The purpose of theapertures 18 is to provide access to contact points in the interior of the card as will soon be readily apparent.

The middle layer orlamina 20 is also a substantially flat, thin piece of pliable plastic material which is electrically nonconductive as arelayers 12 and 16. on thesurface oflamina 20 which when bonded will be facing thebottom layer 16 there is deposited or etched a plurality of electrical contact points 22. Contact points 22 are symmetrically arranged on this surface oflayer 20 in the same manner as are theapertures 18 inlayer 16 providing a system which can be described by numerical or alpha-numerical coordinates and these contact points are positioned to coincide withapertures 18. As shown in FIG. 2 and more completely in FIGS. 4 and 6, deposited on the surface oflamina 20 are a plurality ofdiodes 24. Each of the contact points 22 is connected to one or more of these diodes by means ofconductor paths 26 which are also etched upon the surface oflamina 20. The diodes are thus connected in strings, the polarities being alternated at random, and the strings not necessarily connected together. The excep tion to the foregoing statement is that three or more of these contact points will not be interconnected to these diodes but will be connected to a semiconductor device.

FIG. 4 shows one embodiment of the invention in which the semiconductor is aunijunction transistor 28 deposited upon a surface ofintermediate layer 20 which can be made, according to present technology very small so as not to provide a bulky area or excess thickness in the card.Unijunction 28 has anemitter electrode 30, and twobase electrodes 32 and 34. Each of these electrodes is connected through an etched-on circuit path, respectively to selected ones of the contact points 22a, those contact points being ones which are not interconnected to any of thediodes 24. As shown in FIG. 4, in which the set of coordinates established by the contact points is numbered from left to right, it is shown that theemitter electrode 30 is connected to the contact point indexed No. 56, thebase electrode 32 is connected to the contact point indexed No. 22 and theother base electrode 34 is connected to the contact point indexed No. 108. Thus, the code number established by the coordinates for the card shown in FIG. 4 is the number 56-22-108.

Turning now to the details of the card verification device, this is pictorially represented in FIG. 1 and indicated generally by the numeral 40. Thedevice 40 in cludes aslot 42 into which the card to be verified shall be inserted. It would be desirable, in order to assure that the card is properly inserted in the slot 4-2 to provide the card with some sort of indexing means. It should be obvious that because the contact points are indexed according to a certain numerical order, it is necessary that the card not be reversed. Thus, the card could have a notch cut in one end as shown at 41 in FIG. 1 which would permit the card to be inserted all the way intoslot 42 there being an embossment 43 (See FIG. 3) which would be received innotch 41 to permit the card to be inserted all the way. The exterior of the card reading device has a number of selector knobs on the exterior thereof. The first series ofknobs 44, 45 and 46 are multiple position rotatable switches used to select an index number. Another series ofknobs 47, 48 and 49 are again multiple position switches having three or more positions which select which set of the series of numbers in the combination shall correspond to the number selected by the corresponding number selection switch. In other words, in order to prevent someone from learning the combination of the credit card, the user may selectswitch 48 to be the first digit whereupon he will set that to the first digit position and then setdial 45 to his first number, in our case that beingnumber 56 then he might select theknob 47 to be the second digit whereupon he will adjustknob 44 tonumber 22, and so on. After having properly adjusted all of these knobs, the card holder or the attendant depressesbutton 50 and if the proper card has been properly inserted and the numbers properly selected as aforesaid, anindicator light 52 will be lighted indicating and thereby verifying that the card holder is in possession of a proper card.

As previously described,bottom layer 16 of the card is provided with a series ofapertures 18. In FIG. 3, the card is shown inserted inslot 42 with thebottom layer 16 facing downwardly. In the interior ofslot 42 there is positioned a plurality ofcontact members 54 herein shown as electrically conducting spheres. Thecontact spheres 54 are held in place by aperforated plate 56 havingapertures 58 therein, the diameter of which is slightly less than the diameter ofspheres 54. The spheres are biased upwardly by springs 60 which also provide electrical conducting paths and to which are connected conductor leads 62. It should be apparent that whencard 10 is properly inserted all the way inslot 42 all of thecontact spheres 54 will reside in theapertures 18 providing electrical connections to eachcontact point 22.

FIG. 5 shows one embodiment of an electrical circuit diagram contained in thecard verification unit 40 specifically a circuit to operate in conjunction with the unijunction device shown in FIG. 4. The three coordinatenumber selecting switches 44, 45 and 46 are shown with the contacts being dependent upon the number of contact points designed to be on each card. To the contact points 64 are connected theconductors 62 which connect to the spring contacts as previously described. It should be apparent that all of thecontacts 64 assigned No. l are connected to spring contact No. 1 and so on. TheWiper 66 ofselector switch 44 connects through condctor 68 to one of the terminals of each of the digit selector switches 47, 48 and 49. Likewise, the wipers of the othernumber selecting switches 45 and 46 connect to corresponding terminals'on digit selector switches 47 and 48.

Assuming the digit and number selectors are properly set,line 72 connected towiper 70, will be coupled to the emitter ofunijunction 28,line 74 connected to wiper 76 will be coupled to onebase 32 andline 78 connected to wiper 80 will be coupled to theother base electrode 34.Conductor 72 is connected tojunction point 82 betweencapacitor 84 andvariable resistor 86 which are coupled in series.Capacitor 84 is connected to thenegative ground bus 88 to which is connected the negative terminal ofbattery 90.Resistor 86 is coupled throughpositive bus line 87 to pushbutton switch 92, relay contact 98a andpower switch 94 to the positive terminal ofbattery 90.Line 74 is connected through series resistor 96 topositive bus line 87.Line 78 is connected to one side ofrelay coil 87.Line 78 is connected to one side ofrelay coil 98 the other side of which is connected tonegative bus 88.Relay coil 100 is coupled in series withresistor 102 betweennegative bus 88 andpositive bus 87. Relay contact 100a is normally open (operated in response to current in relay coil 100) is coupled acrossswitch 92.

Lamp 104 is coupled in series with relay contacts 98b and b, both of which are normally closed, betweennegative bus 88 andpositive bus 87.Lamp 106 is coupled in series with relay contact 100a, which is normallyopen, betweennegative bus 88 andpositive bus 87. In this configurations as properly connected to the unijunction transistor, the circuit is a relaxation oscillator,lamp 104 indicating when power normally open on andlamp 106 indicating proper interconnection Of the unijunction into the oscillator circuit.

Following are typical types and values of the circuit elements employed in this circuit:

2N 16718 Texas Inst. I00 MicrofaradUnijunction transistor Capacitor 84 26.5VDC, 700Ohm 24 VDC Power supply Whenpower switch 94 is closed,lamp 104 lights indicating the system is ready. The DC voltage is applied across thepush button switch 92 which when depressed applies current throughrelay coil 100 closing contactsl00a across theswitch 92, and openingcontacts 10% with the result thatlamp 104 goes out. At the same time contacts 100a close turning onlamp 106. Release ofswitch 92 will not change this condition. DC power will also be applied tobase electrode 32 through resistor 96 and current will also flow throughcapacitor 84 starting it to charge. After a specific time determined by the values ofresistor 86 andcapacitor 84, the charge on the capacitor will bias theemitter 30 sufficiently to causeunijunction 28 to conduct. When it conducts,capacitor 84 discharges throughbase electrode 34 and throughrelay coil 98. The current throughcoil 98 being sufficient to momentarily energize the relay, contacts 98a and 98b both open, cutting off current to relay 100 and thereby returning the entire circuit to its original state.

The flashing sequence oflamps 104 and 106 indicates proper connection of the card into the circuit. Iflamp 106 is green andlamp 104 is red, the sequence will be first a green light, then upon depressing switch 92 a red light for a preset time, followed by a green light again.

Improper connection of the card contacts into this circuit will cause either no change in the initial green light signal or other sequences all indicating wrong code selection. For example, ifconductors 74 and 78 were connected across a diode of the wrong polarity,relay 100 would energize turning on the red lamp, but relay 98 will never energize so the red lamp will remain lit. Ifconductors 74 and 78 were conducted across a diode of proper polarity both relays will energize but contact 98a will keep opening andclosing causing lamps 104 and 106 to continue blinking on and off as long asswitch 92 is depressed. The same action will occur ifconductors 72 and 74 are coupled across a diode of either polarity.Relay 98 will never energize, thus keeping thered lamp 106 on.

The chains ofdiodes 24 to which the unused contact points are connected provide a means for giving erroneous electrical readings between the inactive contact points so that someone trying to electrically determine the combination number through resistance measurements would not be able to do so. Resistance measurement between contact points will indicate either a small finite resistance representing the forward resistance of the diodes (about 200 ohms) or the unijunction or an open circuit indicative of the back resistance of one or more diodes or the unijunction. The forward resistance of the unijunction is E to B approximately 200 ohms, E to B 600 ohms and I? to B infinite To effectively decode the card would take a three element resistance check and it should be recalled that there are over one million possible combinations. With all of these measurements. it is clear that the investigator has determined nothing about the location of the proper contact points. A card containing 100 electrical contact points, of which three are active, provides one million possible combinations. Since the correct selection of theswitches 47, 48 and 49 is also required, this multiplies the number of possible combinations by three. Four terminal semiconductor devices are also available which if used could raise the number of possible combinations to three hundred million.

FIGS. 6 through 8 set forth another embodiment of the invention ofa more simplified form. Here, the operative semiconductor element comprises aNAND circuit 120 deposited upon theintermediate lamina 20.NAND circuit 120 hasinput terminals 121 and 123 which are coupled to unused contact points 122 and 124 respectively, and anoutput terminal 125 connected to contact point 126. In addition, the NAND circuit requires biasing, so the positive or B+ terminal is connected to contactpoint 128 and the negative or B- terminal is connected to contactpoint 130. because all cards using a NAND circuit will require this biasing, contact points 128 and 130 may preferably be additional to the contact points making up the encoding grid and may be situated along the edges of the card. Location of the biasing contacts within the encoding grid would of course increase the number of possible code combinations but may make false readings possible.

In FIG. 7, the switching apparatus previously described in connection with FIG. schematically designated by theboxes 132, 133 and 134 inasmuch as the details thereof are the same.Switches 132 and 133 couple theinputs 122 and 124 through apush button switch 136 to aDC power supply 138 the output of which may be aslow as 1 VDC. The output terminal 126 is coupled throughswitches 134, throughZener diode 140, toindicator lamp 142 to thenegative terminal 144 ofsupply 138. Thenegative supply terminal 144 couples directly to the card 8-terminal 130. Thepositive supply terminal 146 of approximately 4 VDC is coupled throughpower switch 148 to the 13+terminal 128.power lamp 150 is coupled acrossswitch 148 andnegative supply terminal 144.

When switched on,lamp 150 preferably green is it. If the proper contact points the card are selected, depression ofswitch 136 will produce an output at terminal 126 of sufficient amplitude to causeZener diode 140 to conduct, causingindicator lamp 142 to light, signifying a proper code selection. Zener diode having a Zener level of about 3 VDC will prevent improper input connections from causinglamp 142 to light since the input signals are only about 1 VDC.

FIG. 8 is the equivalent circuit of a typical NAND gate employing two transistors and appropriate biasing resistors. It will be readily apparent that resistance measurements made attempting to decode a card will not be fruitful because the overall diode matrix will produce similar results. With the NAND gate biasing points separate from the encoding matrix, it cannot be shorted to the output, so a false reading cannot occur in that way either.

FIGS. 9a and 9b set forth an improved embodiment of the present invention in that the circuitry therein shown provides the previously discussed feature of having a single unique code sequence for a card together with the provision of false code indications so that the card cannot be easily decoded but this embodiment permits the reduction of contact points on the card, and therefore on the card verifying unit to a very low number while still permitting an extremely large number of possible code combinations. The obvious advantage of reducing the number of contact points is that it will reduce the number of possible mechanical failures in reading or verifying cards. It is apparent that for a large number of contact points, it is possible that one of the important contacts may become dirty and fail to make the proper electrical contact with the verifier unit, or the spring loaded contacts of the verifier unit may, upon continued usage, suffer some mechanical defect which could result in wrongly failing to properly verify a good card. It is important that the card verifiers be dependable so that customers who use them and proprietors who have them can maintain a high degree of confidence in them.

The verification unit, the circuitry of which is shown in FIG. 9b may be constructed in virtually any configuration, it being necessary only that there be provided the number of contact points to be hereinafter discussed together with a number of momentary contact switches or push buttons and a pair of multi-positioned rotary switches. It will be seen from the ensuing discussion that the power supply requirement of this particular circuitry is extremely low so that the unit can be small, portable and self contained. The verification unit consists of 14 contact points generally designated in FIG. 9b by the numeral 200 and these contact points are indexed by thedigits 0 through 9, letters A" and B" and signs and Each of the contact points 200 is coupled to oneterminal 202 of momentary push button switches 204. A first rotary switch 206 has a wiper arm 208 and a plurality ofcontacts 210. Asecond rotary switch 212 is similarly provided with a wipearm 214 and a plurality ofcontacts 216. Theswitch contacts 210 and 216 have, in addition to of positions to which no connections are made, connections indicated by the arrows and numered from 0" to 9 which are coupled in turn to theterminals 202 of the push button switches 204 numbered 0 through 9 and A" and B so thatcontacts 210 and 216 are coupled in parallel to the correspondingly numbered push button switches, such as one-one, two-two, etc. The exception to the foregoing manner of connection is that one of the contacts 210a, which may be any of the numberedcontacts 210 is coupled throughconductor 218 to terminal 202aof push button switch 2040, which is in turn also coupled to the contact designated by the letter A. Similarly, one of the contacts 21Gb ofrotary switch 212 is coupled throughconductor 220 to terminal 20217 of push button switch 204b, that terminal also being coupled to the contact indexed with the letter B.

Apower switch 222 has one contact coupled to a source of positive DC voltage, herein designated as theB+ terminal 224 and, for example, the value of the 13+ voltage is indicated as 10.5 volts DC. The other terminal ofswitch 222 is coupled toground terminal 226. All of the push button switches 204 have their other terminals tied to acommon bus line 228 which in turn is coupled toconductor 230 to thebase electrode 232!) oftransistor 232. Thecollector 2320 is coupled through anappropriate biasing resistor 234 to theB+ line 235. The emitter 232e is likewise coupled to the B+line 235 through biasingresistor 236, as is the base electrode 232b coupled throughresistor 238. The emitter 232e is similarly coupled throughresistor 240 toconductor 242 which is connected to thewiper 214 ofswitch 212. Thewiper 214 is also coupled through aconductor 244 to thegrounding terminal 226 ofswitch 222. The circuit also includes acapacitor 246 coupled between base electrode 232b andground conductor 242.

The emitter 248e oftransistor 248 is connected directly to theB+ line 235, thecollector electrode 2480 is coupled to the wiper 208 of rotary switch 206. Thus, power is supplied to the circuit upon the closure ofswitch 222 so that positive potential is applied throughline 235 totransistor 232 and 248, a common ground for the circuit being coupled throughswitch contacts 226 to the wiper ofswitch 212, and in the configuration shown in FIG. 9b,ground will be supplied throughconductor 220 to the contact point B coupled to push button switch 202b. When power is applied to the circuit, the base oftransistor 232 goes positive and supplies approximately I /2 volts on thebus line 228 to all of theswitches 204. The collector oftransistor 248 also goes positive supplying plus 10.5 volts to the wiper 208 and throughconductor 218 to the contact terminal 202a. Thus, in the configuration of the circuit shown in FIG. 9b, the unit provides a1 V2 volt trigger signal to all of the 14 contacts; and, through the selector switches 206, 212, anode voltage of plus 10.5 volts to any one of the contacts, and ground potential to any other one of the contacts. The indicia herein given to the various contacts are for the purpose of explanation and it is equally possible that other numerical systems or alphanumerical systems may be adopted for the contacts other than the and or the other indices herein indicated.

Turning now to FIG. 9a, there is shown a plurality of silicon controlled rectifiers (SCR), there being 14 in number. Of those 14 SCRs, six are employed for the purpose of providing a false code signal, seven are employed to establish a six-digit code and a final SCR is used to control the function of an output indicator.SCRs 250, 252, 254, 256, 258 and 260 each have their gate electrodes connected directly to the contact points on the card herein designated by theindex digits 1, 4, 6, 5," 7 and respectively. These gate electrodes are likewise coupled throughresistors 251, 253, 255, 257, 259, 261 to the cardcommon ground bus 262 which is in turn coupled to contactpoint 264 indexed B. The anodes of SCRs 250-260 are all coupled in parallel and connected toB+ conductor 266, which is in turn coupled to contactpoint 268 herein designated A." The cathodes of SCRs 250-260 are coupled in parallel and connected toconductor 270.SCRs 272, 274 and 276 are coupled in series with the anode ofSCR 272 coupled to 8+line 266. The gate electrodes ofSCRs 272, 274 and 276 are connected directly to contact points on the card herein designated by thedigits 2, and 8". These gate electrodes are likewise coupled throughresistors 273, 275, 277 respectively toground bus 278 which is in turn coupled to theother ground bus 262.Resistors 280, 281 and 282 are coupled between the cathodes ofSCRs 272, 274 and 276 respectively and ground, to keep each SCR conducting after removal of its respective trigger signal until the next successive SCR is made conductive.

AnotherSCR 282 has its anode coupled toB+ line 266 and its cathode coupled in series withSCRs 284, 286 and 288. The gate electrode ofSCR 282 is coupled through aresistor 290 to the cathode ofSCR 276. The gate electrodes ofSCRs 284, 286 and 288 are connected directly to contact points on the card herein given theindex digits 3," 9" and 0". As withSCR 272,SCRs 284, 286 and 288 are provided with resistors coupled between the gate electrodes and ground and between their cathodes and ground, with theexception SCR 288 the cathode of which is coupled to one terminal ofalight emitting diode 290 the other terminal of which is coupled throughresistor 292 to ground. Anadditional SCR 294 is connected across thelight emitting diode 290, with its anode coupled to the cathode ofSCR 288, and the cathode ofSCR 294 coupled to the junction between thediode 290 andresistor 292. The gate electrode ofSCR 294 is coupled throughresistor 296 toconductor 270 and throughresistor 298 to ground.

The index digits mentioned herein as assigned to the contact points on the card are given for illustrative purposes only, it being understood that the indexing of the card contacts may be done so as to provide any combination of digits. Here, the first two digits of the combination are determined by theswitches 206 and 212 and the positions of those switches which provide the utputs to contacts A" and B. With reference to FIG. 9b, it will be indicated that the positions of those two rotary switches would correspond toindex digits 5 and 3 for letters A" and B respectively. In this manner, proper connection of those terminals to contacts A" and 8" will provide appropriate 13+ and ground terminals tocontacts 268 and 264 on the card. The third, fourth and fifth digits in the code will be represented byindex digits 2, and 8 and the remaining digits in the code number will be determined by the connections of the gate electrodes ofSCRs 284, 286 and 288, here shown to be assigned thedigits 3, 9 and 0." Thus, the combination of the card shown in the drawings is AB2-8390.

When the proper combination of the card is known, and the card is inserted in the verification unit until all contacts are properly made, the rotary switches 206 and 212 are moved to the proper positions, here positions A and B or 5 and 3 respectively.Power switch 222 is closed and the verification unit will thereby provide a positive anode voltage at contact A and a ground connection to contact B, plus an SCR trigger voltage available at each push button switch throughcommon bus 228. Anode voltage is provided to all of theSCRs 250260, 272 and 283. The trigger voltage is available to each gate of each SCR through the contacts except of course the gates to SCRs 283 and 294. The next six digits of the combination are introduced into the card by pushing the proper push buttons in the correct sequence, in this case 2-8390." Whenpush button 2 is depressed, a trigger voltage is applied to the gate ofSCR 272 causing current to flow through the SCR and through thecathode resistor 280 to ground so thatSCR 272 is turned on and maintained in that condition, at the same time supplying anode voltage toSCR 274. When the dash or minus button is depressed,SCR 274 will be turned on in a similar manner supplying anode voltage toSCR 276 which is in turn turned on by depression of push button corresponding to that number. The resistors coupled between the gates of the SCRs to ground desensitize the gates so that they will not trigger the SCRs in the event there is a stray noise. WhenSCR 276 is turned on it turns on automaticallySCR 283 thereby enablingSCR 284 and supplies to the anode ofSCR 284 the full anode voltage. It has been found that due to junction voltage drops occuring between the anode and cathode of an SCR, where SCRs are cascaded, the voltage drop is too great if more than three SCRs are coupled in series. Accordingly the series combination ofSCR 272, 274 and 276 is provided to trigger theintermediate SCR 283 which thereby supplies full anode voltage to the next successive series of three SCRs. Then, whenpush buttons 3," 9" and are depressed, each of thecorresponding SCRs 284, 286 and 288 will fire, each enabling the following SCR to fire in the same manner. When the 0 push button is depressed, power is supplied to thelight emitting diode 290 which lights to signify that the correct combination has been introduced in the correct sequence, thereby verifying that the owner of the card has properly identified himself.

If the proper combination is not known, particularly if the proper positions forrotary switches 206 and 212 are not known, proper bias can never be supplied to the card circuit. Even assuming that those proper positions are known, only SCR 272 can be turned on even if all of the push buttons are depressed. Assuming thatSCR 272 was turned on, then ifpush button 9, for example, is depressed,SCR 286 would have no anode voltage and cannot be fired. Furthermore, the trigger voltage supplied to the gate ofSCR 286 will be coupled through the gate resistor to ground and would causeSCR 272 to turn off. Any other wrong sequence will have the same effect. The reason that the circuit works in the correct sequence is that the SCRs, when they have anode voltage, will turn on fast enough to keep the reviously fired portion of the circuit from resetting. If any push button other than those numbers which comprise the correct combination or code sequence are depressed, the corresponding SCR will fire sinceSCR 250, for example, will always have anode voltage and if button l isdepressed SCR 250 will indeed fire. The output of SCRs 250-260, i.e., their cathodes, are all coupled throughline 270, throughresistor 296 to the gate ofSCR 294. If any outputs are obtained from SCRs 250-260 they will triggerSCR 294 on so that current will be shunted across thediode 290 thereby preventing it from turning on. Therefore, even if the proper code sequence was used, pushing any one button corresponding to a number which is not an element of the sequence, the LED will not light sinceSCR 294 would be enabled, there being an available anode voltage to it as soon as an output is obtained fromSCR 288.

It is necessary that the first SCR of the proper code sequence be immediately enabled and for that reason the anode of 272 is connected directly to theB+ conductor 266. It would be possible to determine electrically which is the first digit of the code by determining which SCR turns on first, and then the next SCR and so on. But, SCRs 250-260 are provided to give an additional set of SCRs which can be turned on at any time to further confuse the investigator. These six SCRs will effectively hide which SCR out of thegroup 250260 and 272 is the correct first digit since any of them can be turned on first. It will also be noted that any of the six SCRs 250-260 can be turned on one after the other and by coupling those SCRs in parallel with essentially no load and all having anode voltage it has been found that the SCRs will interact between themselves in random fashion based upon the inherent internal characteristics of each SCR, its relative location within the circuit, the number of other SCRs that have been turned on, etc. In other words, it is possible that all six of the SCRs can be turned on, but in most cases several will be turned on and then when a button is depressed to turn on an additional one, it may reset one or all of the others in a random fashion which makes an electrical investigation of the circuit extremely confusing.

It will thus be seen that the present invention has provided a greatly improved method of credit card verification and which will substantially reduce credit card misuse. While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those persons skilled in the art that changes and modifications might be made and it is, therefore, contemplated that such changes and modifications are within the scope of this invention.

I claim:

1. An improved identity verification system, comprising:

a card, a plurality of contact points situated upon said card, first and second circuit means embedded within said card, three or more of said contact points being coupled to said first circuit means and providing a unique set of contact points, the remainder of said contact points being coupled to said second circuit means;

card reader means comprising contact means for establishing electrical contact with each of the contact points of said card, third circuit means in said reader means, a plurality of selector means electrically coupled between said contact means and said third circuit means for selectively coupling individual ones of said contact means to said third circuit means; and

indicator means coupled to said first and third circuit means, said indicator means providing an output signal when said first and third circuit means are coupled together.

2. The system set forth in claim 1 wherein said indicator means includes first and second output means, said first output means providing a first output signal when all of said contact points are coupled to said first circuit means, and said second output means providing a second output signal when any of said contact points are coupled to said second circuit means.

3. The system set forth in claim 1 wherein said first circuit means comprises a three terminal semiconductor device.

4. The system set forth in claim 1 wherein said first circuit means comprises a unijunction transistor.

5. The system described in claim 1 wherein said first circuit means comprises a NAND gate.

6. The system described inclaim 3 wherein said second circuit means comprises a plurality of diodes coufi J pled in randomly-oriented fashion between various of said contact points.

7. The system described in claim 1 wherein:

said first circuit means comprises a unijunction transistor, the three terminals of which are connected to three individual ones of said contact points; and

said second circuit means comprises a plurality of diodes coupled in randomly-oriented fashion between all the remaining ones of said contact points.

8. The system described in claim 1 wherein:

said first circuit means comprises a NAND gate having two input terminals, one output terminal and two bias terminals, each of said terminals being connected to individual ones of said contact points; and

said second circuit means comprises a plurality of diodes coupled in randomly-oriented fashion between all the remaining ones of said contact points.

9. The system described in claim 1 wherein:

said first circuit means comprises a first plurality of silicon-controlled-rectifiers coupled in series circuit relationship, each of said rectifiers having a gate electrode coupled to one of said contact points which define said unique set of points, the last in said series of rectifiers having an output conductor coupled to said indicator means;

said second circuit means comprises a second plurality of silicon-controlled-rectifiers coupled in parallel circuit relationship, each of said rectifiers having a gate electrode coupled to one of the remainder of said contact points, said second plurality of rectifiers having an output conductor coupled to said indicator means.

10. The system set forth inclaim 9 were in said indicator means comprises a light-emitting diode coupled to theoutput conductor 7 of said first rectifiers, a silicon-controlled-rectifier coupled in parallel with said diode, said silicon-controlled-rectifier having a gate electrode coupled to the output conductor of said second plurality of rectifiers.

I]. The system described in claim 1 wherein said card reader includes means for selectively sensing said contact points, said means comprising means for receiving a card in the reader, contact means in said receiving means for contacting each of said contact points, a plurality of switching means coupled to said contact means for selecting certain ones of said contact means according to the aforesaid system of index numbers assigned to the contact points on a card, said switching means having indexing means for selecting contact points according to said series of code numbers.

12. The system described in claim 11 wherein said indicating means in said card reading means comprises a fourth circuit means, said fourth circuit means having first and second output indicating devices, a source of electrical power, means for coupling said source of power to said switching means, current responsive means coupled to said switching means and said indicating devices, said current responsive means being operative to energize said first output device when said switching means is coupled only to said first circuit means in a card, said current responsive means operative to energize said second output device when said switching means is not coupled only to said first circuit means.

13. An improved identity verification system, the combination comprising:

a card, first and second circuit means embedded in aid card, a plurality of contact points upon said card, said contact points disposed in a matrix pattern, said first circuit means being coupled to more than two but substantially less than all of said contact points, said second circuit means being coupled to all of the remaining contact points;

a card reader having means for receiving a card therein, contact means situated in said receiving means, said contact means disposed in a matrix pattern adapted to register with the contact points of a card, third circuit means situated in said card reader, selector means coupling said third circuit means to said contact means whereby any one of said contact points of a card may be coupled into said third circuit, said third circuit means including indicator means, said third circuit means being operative to provide an output at said indicator means when said selector means has been actuated to couple only said first circuit means to said third circuit means.

14. An improved identification card and a system for verification thereof comprising, in combination:

a card comprising at least two lamina adhered together, said card having a matrix of electrical contact points disposed upon a surface of one of said laminae, access means formed upon one or more surfaces of said card for permitting access to said contact points, a first plurality of semiconductor means disposed within said matrix and interconnecting substantially all of said contact points in random fashion, one or more second semiconductor devices having three or more terminals, said terminals being connected to individual remaining ones of said contact points thereby defining a unique combination of points within said matrix;

a card reading apparatus for verifying ownership of said card, said apparatus having means for receiving a card therein, a plurality of contact means situated within said receiving means for making electrical contact with the aforesaid contact points of said card, selector means coupled to said contact means for selecting individual ones of said contact points, circuit means coupled to said selector means, said circuit means including means responsive to the aforesaid second semiconductor devices to produce a unique output signal when said selector means has been actuated to couple said second semiconductor devices to said circuit means.

15. The system described inclaim 12 wherein said current responsive means comprises a relaxation oscillator.

16. The system set forth in claim 1 wherein said first and second circuit means of said card have portions thereof coupled together therein whereby external electrical measurements taken at said contact points will not indicate which contact points are unique to said first circuit means.

17. The system as set forth inclaim 9 wherein said first and second circuit means of said card have portions thereof coupled together therein whereby exter nal electrical measurements taken at said contact points will not indicate which contact points are unique to said first circuit means.

a card having a plurality of contact points situated thereon defining a matrix, first and second circuit means embedded within said card, said first circuit thereon defining a matrix, first and second circuit means comprising one or more first circuit compomeans embedded within said card, said first circuit nents coupled to selected ones of aid contact means comprising one or more first circuit compopoints, said selected contact points thereby delinnents coupled to selected ones of said contact ing a unique code number within said matrix, said points, said selected contact points thereby definsecond circuit means comprising a plurality of secing a unique code number within said matrix, said ond circuit components coupled to the remainder second circuit means comprising a plurality of secof said contact points of said matrix, said second ond circuit components coupled to the remainder circuit components having individual electrical of said contact points of said matrix, said second characteristics substantially similar said first circuit circuit components having individual electrical components, said remainder of contact points coucharacteristics substantially similar to said first cirpled to said second components thereby defining cuit components, said remainder of contact points 5 false code numbers within said matrix; coupled to said second components thereby defmcard reading means comprising contact means for siing false code numbers within said matrix; multaneously establishing electrical contact with card reading means comprising contact means for siall of the contact points of said card, third circuit multaneously establishing electrical contact with means, coded selector means coupled between said all of the contact points of said card, third circuit 20 contact means and said third circuit means; and means, coded selector means coupled between said indicator means coupled to said first and second circontact means and said third circuit means, and incuit means, said indicator means including means dicator means coupled to said third circuit means providing a visual indicator when said first circuit for indicating whether or not said coded selector means has been coupled to said third circuit means means has coupled the contact points of said first according to said unique code number, said visual circuit means with said third circuit means accordindication means providing no visual indication ing to said unique code number. whenever any portion of said second circuit means 19. An improved identification card verification sysis coupled to said third circuit means. tem comprising:

Claims (19)

1. An improved identity verification system, comprising: a card, a plurality of contact points situated upon said card, first and second circuit means embedded within said card, three or more of said contact points being coupled to said first circuit means and providing a unique set of contact points, the remainder of said contact points being coupled to said second circuit means; card reader means comprising contact means for establishing electrical contact with each of the contact points of said card, third circuit means in said reader means, a plurality of selector means electrically coupled between said contact means and said third circuit means for selectively coupling individual ones of said contact means to said third circuit means; and indicator means coupled to said first and third circuit means, said indicator means providing an output signal when said first and third circuit means are coupled together.

2. The system set forth in claim 1 wherein said indicator means includes first and second output means, said first output means providing a first output signal when all of said contact points are coupled to said first circuit means, and said second output means providing a second output signal when any of said contact points are coupled to said second circuit means.

3. The system set forth in claim 1 wherein said first circuit means comprises a three terminal semiconductor device.

4. The system set forth in claim 1 wherein said first circuit means comprises a unijunction transistor.

5. The system described in claim 1 wherein said first cirCuit means comprises a NAND gate.

6. The system described in claim 3 wherein said second circuit means comprises a plurality of diodes coupled in randomly-oriented fashion between various of said contact points.

7. The system described in claim 1 wherein: said first circuit means comprises a unijunction transistor, the three terminals of which are connected to three individual ones of said contact points; and said second circuit means comprises a plurality of diodes coupled in randomly-oriented fashion between all the remaining ones of said contact points.

8. The system described in claim 1 wherein: said first circuit means comprises a NAND gate having two input terminals, one output terminal and two bias terminals, each of said terminals being connected to individual ones of said contact points; and said second circuit means comprises a plurality of diodes coupled in randomly-oriented fashion between all the remaining ones of said contact points.

9. The system described in claim 1 wherein: said first circuit means comprises a first plurality of silicon-controlled-rectifiers coupled in series circuit relationship, each of said rectifiers having a gate electrode coupled to one of said contact points which define said unique set of points, the last in said series of rectifiers having an output conductor coupled to said indicator means; said second circuit means comprises a second plurality of silicon-controlled-rectifiers coupled in parallel circuit relationship, each of said rectifiers having a gate electrode coupled to one of the remainder of said contact points, said second plurality of rectifiers having an output conductor coupled to said indicator means.

10. The system set forth in claim 9 werein said indicator means comprises a light-emitting diode coupled to the output conductor of said first rectifiers, a silicon-controlled-rectifier coupled in parallel with said diode, said silicon-controlled-rectifier having a gate electrode coupled to the output conductor of said second plurality of rectifiers.

11. The system described in claim 1 wherein said card reader includes means for selectively sensing said contact points, said means comprising means for receiving a card in the reader, contact means in said receiving means for contacting each of said contact points, a plurality of switching means coupled to said contact means for selecting certain ones of said contact means according to the aforesaid system of index numbers assigned to the contact points on a card, said switching means having indexing means for selecting contact points according to said series of code numbers.

12. The system described in claim 11 wherein said indicating means in said card reading means comprises a fourth circuit means, said fourth circuit means having first and second output indicating devices, a source of electrical power, means for coupling said source of power to said switching means, current responsive means coupled to said switching means and said indicating devices, said current responsive means being operative to energize said first output device when said switching means is coupled only to said first circuit means in a card, said current responsive means operative to energize said second output device when said switching means is not coupled only to said first circuit means.

13. An improved identity verification system, the combination comprising: a card, first and second circuit means embedded in aid card, a plurality of contact points upon said card, said contact points disposed in a matrix pattern, said first circuit means being coupled to more than two but substantially less than all of said contact points, said second circuit means being coupled to all of the remaining contact points; a card reader having means for receiving a card therein, contact means situated in said receiving means, said contact means disposed in a matrix pattern adapted to register with the contact points of a card, third circuit means situAted in said card reader, selector means coupling said third circuit means to said contact means whereby any one of said contact points of a card may be coupled into said third circuit, said third circuit means including indicator means, said third circuit means being operative to provide an output at said indicator means when said selector means has been actuated to couple only said first circuit means to said third circuit means.

14. An improved identification card and a system for verification thereof comprising, in combination: a card comprising at least two lamina adhered together, said card having a matrix of electrical contact points disposed upon a surface of one of said laminae, access means formed upon one or more surfaces of said card for permitting access to said contact points, a first plurality of semiconductor means disposed within said matrix and interconnecting substantially all of said contact points in random fashion, one or more second semiconductor devices having three or more terminals, said terminals being connected to individual remaining ones of said contact points thereby defining a unique combination of points within said matrix; a card reading apparatus for verifying ownership of said card, said apparatus having means for receiving a card therein, a plurality of contact means situated within said receiving means for making electrical contact with the aforesaid contact points of said card, selector means coupled to said contact means for selecting individual ones of said contact points, circuit means coupled to said selector means, said circuit means including means responsive to the aforesaid second semiconductor devices to produce a unique output signal when said selector means has been actuated to couple said second semiconductor devices to said circuit means.

15. The system described in claim 12 wherein said current responsive means comprises a relaxation oscillator.

16. The system set forth in claim 1 wherein said first and second circuit means of said card have portions thereof coupled together therein whereby external electrical measurements taken at said contact points will not indicate which contact points are unique to said first circuit means.

17. The system as set forth in claim 9 wherein said first and second circuit means of said card have portions thereof coupled together therein whereby external electrical measurements taken at said contact points will not indicate which contact points are unique to said first circuit means.

18. An improved identification card verification system comprising: a card having a plurality of contact points situated thereon defining a matrix, first and second circuit means embedded within said card, said first circuit means comprising one or more first circuit components coupled to selected ones of said contact points, said selected contact points thereby defining a unique code number within said matrix, said second circuit means comprising a plurality of second circuit components coupled to the remainder of said contact points of said matrix, said second circuit components having individual electrical characteristics substantially similar to said first circuit components, said remainder of contact points coupled to said second components thereby defining false code numbers within said matrix; card reading means comprising contact means for simultaneously establishing electrical contact with all of the contact points of said card, third circuit means, coded selector means coupled between said contact means and said third circuit means, and indicator means coupled to said third circuit means for indicating whether or not said coded selector means has coupled the contact points of said first circuit means with said third circuit means according to said unique code number.

19. An improved identification card verification system comprising: a card having a plurality of contact points situated thereon defining a matrix, first and second circuit means embedded wIthin said card, said first circuit means comprising one or more first circuit components coupled to selected ones of aid contact points, said selected contact points thereby defining a unique code number within said matrix, said second circuit means comprising a plurality of second circuit components coupled to the remainder of said contact points of said matrix, said second circuit components having individual electrical characteristics substantially similar said first circuit components, said remainder of contact points coupled to said second components thereby defining false code numbers within said matrix; card reading means comprising contact means for simultaneously establishing electrical contact with all of the contact points of said card, third circuit means, coded selector means coupled between said contact means and said third circuit means; and indicator means coupled to said first and second circuit means, said indicator means including means providing a visual indicator when said first circuit means has been coupled to said third circuit means according to said unique code number, said visual indication means providing no visual indication whenever any portion of said second circuit means is coupled to said third circuit means.

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