US20050270159A1 - Combination radio frequency identification transponder (RFID Tag) and magnetic electronic article surveillance (EAS) tag - Google Patents

Abstract

A combination of a radio frequency identification transponder (RFID Tag) and to a magnetic electronic article surveillance (EAS) device is disclosed. The present invention relates generally to radio frequency identification (RFID) systems, and more specifically to RFID transponders for use in RFID systems and the method for their assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• The present application is a continuation of application Ser. No. 10/985,665 filed Nov. 10, 2004, which is a continuation of application Ser. No. 10/772,221 filed Feb. 4, 2004, which is a continuation of application Ser. No. 09/181,505 filed Oct. 28, 1998, now abandoned, which is a continuation in part of U.S. application Ser. No. 09/071,413 filed May 1, 1998, now U.S. Pat. No. 5,939,984 issued Aug. 17, 1999. Said application Ser. No. 09/071,413 in turn claims the benefit of U.S. Provisional Application No. 60/070,136 filed Dec. 31, 1997. Said application Ser. No. 09/181,505 claims the benefit of U.S. Provisional Application No. 60/102,476 filed Sep. 30, 1998, and also claims the benefit of U.S. Provisional Application No. 60/093,088 filed Jul. 16, 1998. The present application is also a continuation in part of application Ser. No. 10/391,515 filed Mar. 18, 2003, which is a continuation of application Ser. No. 09/136,157 filed Aug. 18, 1998, now U.S. Pat. No. 6,535,108 issued Mar. 18, 2003, which is a continuation of application Ser. No. 08/569,375 filed Dec. 8, 1995, now U.S. Pat. No. 5,812,065 issued Sep. 22, 1998, which is a continuation in part of application Ser. No. 08/514,705 filed Aug. 14, 1995, now abandoned. Said U.S. Pat. No. 5,812,065, and said application Ser. Nos. 09/071,413, 60/093,088 and 60/102,476 are herein incorporated by reference in their entirety.
INCORPORATION BY REFERENCE
• The following US Patents and Patent Applications are hereby incorporated herein by reference in their entirety:
U.S. Patents

• Patent No.	Issue Date	Filing Date	Attorney Docket No.
  5,521,601	May 28, 1996	Apr. 21, 1995	YO995-0088
  5,528,222	Jun. 18, 1996	Sep. 09, 1994	YO994-180
  5,538,803	Jul. 23, 1996	Nov. 23, 1994	YO994-0073
  5,550,547	Aug. 27, 1996	Sep. 12, 1994	YO994-185
  5,552,778	Sep. 03, 1996	Nov. 23, 1994	YO994-0232
  5,554,974	Sep. 10, 1995	Nov. 23, 1994	YO994-0071
  5,563,583	Oct. 08, 1996	Nov. 23, 1994	YO994-070
  5,565,847	Oct. 15, 1996	Nov. 23, 1994	YO994-0072
  5,606,323	Feb. 25, 1997	Aug. 31, 1995	YO995-157
  5,635,693	Jun. 03, 1997	Feb. 02, 1995	YO994-0215
  5,673,037	Sep. 30, 1997	Sep. 09, 1994	YO994-184
  5,680,106	Oct. 21, 1997	Oct. 27, 1995	YO995-0219
  5,682,143	Oct. 28, 1997	Sep. 09, 1994	YO994-170
  5,729,201	Mar. 17, 1998	Jun. 29, 1995	YO995-109
  5,729,697	Mar. 17, 1998	Apr. 24, 1995	YO995-076
  5,736,929	Apr. 07, 1998	Jun. 07, 1996	YO996-085
  5,739,754	Apr. 14, 1998	Jul. 29, 1996	YO996-115
  5,767,789	Jun. 16, 1998	Aug. 31, 1995	YO994-213
  5,777,561	Jul. 07, 1998	Sep. 30, 1996	YO996-178
  5,786,626	Jul. 28, 1998	Mar. 25, 1996	YO996-031
  5,812,065	Sep. 22, 1998	Dec. 08, 1995	YO995-124X
  5,821,859	Oct. 13, 1998	Jun. 07, 1996	YO996-084
  5,828,318	Oct. 27, 1998	May 08, 1996	YO996-068
  5,831,532	Nov. 03, 1998	Aug. 12, 1997	YO995-109B
  5,850,181	Dec. 15, 1998	Apr. 03, 1996	YO995-158
  5,874,902	Feb. 23, 1999	Jul. 29, 1996	YO996-037
  5,889,489	Mar. 30, 1999	Oct. 17, 1996	YO996-195
  5,909,176	Jun. 01, 1999	Oct. 23, 1997	YO997-310
  5,942,987	Aug. 24, 1999	Aug. 09, 1996	YO995-218
  5,966,082	Oct. 12, 1999	May 23, 1997	YO997-115
  6,028,564	Feb. 22, 2000	Jan. 29, 1997	YO997-023
  6,097,347	Aug. 01, 2000	Jan. 29, 1997	YO997-024
  6,288,629	Sep. 11, 2001	May 23, 1997	YO997-114

U.S. Provisional Patent Applications

• Application No.	Filing Date	Attorney Docket No.
  60/073,102	Jan. 30, 1998	YO897-0028P1
  60/074,605	Feb. 13, 1998	YO897-0259P1
  60/077,879	Mar. 13, 1998	YO997-0038P1
  60/078,287	Mar. 17, 1998	YO897-0661P1
  60/091,350	Jul. 01, 1998	YO897-0259P2
  60/078,304	Mar. 17, 1998	YO897-0662P1
  60/093,088	Jul. 16, 1998	38384P1

• The following further documents are also incorporated herein by reference in their entirety:
IBM Technical Disclosure Bulletin
• IBM Technical Disclosure Bulletin, Vol. 38, No. 08, August 1995,page 17, “Multifunction Credit Card Package,” by Brady, Moskowitz, and Murphy.
Literature Reference
• D. Friedman, H. Heinrich, D. Duan, “A low-power CMOS integrated circuit for field-powered radio frequency identification (RFID) tags,” 1997 Digest of Technical Papers of the IEEE International Solid-State Circuits Conference (ISSCC), San Francisco, Calif., February 1997.
PCT Published International Applications

• Published.	Publication
  Application No.	Date	Filing Date	Attorney Docket No.
  WO 96/13793	May 09, 1996	Sep. 20, 1995	YO994-242 PCT
  WO 97/09641	Mar. 13, 1997	Jan. 15, 1996	UK9-94-066 PCT

• The present invention relates to an identification tag and more particularly to an identification tag having a large number of bits of information, where the identification tag has an electronic article surveillance function which is difficult to defeat.
DESCRIPTION OF THE RELATED ART
• Radio frequency identification transponders (RFID Tags) have been developed in the last years to take advantage of the fall in semiconductor logic and memory prices. Such tags are available having a single silicon chip attached to a wire or patch antenna. Such tags, however, may be shielded from the high frequency RF used to communicate with the tags. The anti-theft properties of the RFID tags are suspect.
• Magnetic electronic article surveillance (EAS) tags are much less easily shielded from the low frequency magnetic detection fields. Such EAS tags as described below, however, have possibilities of storing only a few bits of information.
• Some conventional magnetic EAS tags have employed the Barkhausen jump effect. Generally, the Barkhausen effect is characterized by a tendency for magnetization induced in a magnetic material to change in discrete steps as an external magnetic field is increased or decreased. (The material is said to be a non-linear magnetic material if the magnetisation of the material is not proportional to the external magnetic field.) A large temporal flux change, df/dt, occurs when such a step takes place, and a sizable voltage may be induced in a sensing or pickup coil.
• For example. U.S. Pat. No. 5,181,020 describes a thin-film magnetic tag having a magnetic thin film formed on a polymer substrate and a method for producing the same. The thin film exhibits a large Barkhausen discontinuity without intentional application of external torsional or tensile stress on use. A particular disclosed use is as a marker or tag for use in an article surveillance system wherein articles may be identified by interrogating the tagged article in a cyclic magnetic field of a predetermined frequency in a surveillance area and detecting a harmonic wave of the magnetic field generated by the tag in the surveillance area. This conventional system is only a single bit element using a single Barkhausen layer with no ability to develop a code to distinguish items.
• U.S. Pat. No. 5,313,192 describes another single bit tag which relies on the Barkhausen effect. The tag of this invention is selected to include a first component comprised of a soft magnetic material which constitutes the bulk of the tag. A second component comprised of a semi-hard or hard magnetic material is integral with the first component. The tag is conditioned such that the second component has activating and deactivating states for placing the tag in active and deactivated states, respectively. Such conditioning includes subjecting the composite tag to predetermined magnetic fields during thermal processing stages. By switching the second component between its activating and deactivating states the tag can be switched between its active and deactived states. A reusable tag with desired step changes in flux which is capable of deactivation and reactivation is thereby realized.
• U.S. Pat. No. 4,980,670 describes a one bit magnetic tag formed from a magnetic material having domains with a pinned wall configuration. The resulting hysteresis characteristic for that material is such that upon subjecting the material to an applied alternating magnetic field, the magnetic flux of the material undergoes a regenerative step change in flux (Barkhausen jump) at a threshold value when the field increases to the threshold value from substantially zero and undergoes a gradual change in flux when the field decreases from the threshold value to substantially zero. For increasing values of applied field below the threshold, there is substantially no change in the magnetic flux of the material. The tag may be deactivated by preventing the domain walls from returning to their pinned condition by, for example, application of a field of sufficiently high frequency and/or amplitude.
• U.S. Pat. No. 4,940,966 describes the use of a plurality of magnetic elements in predetermined associations (e.g. with predetermined numbers of magnetic elements and with predetermined spacings between said elements), for identifying or locating preselected categories of articles. When the articles are caused to move relative to a predetermined interrogating magnetic field, each particular association of magnetic elements gives rise to a magnetic signature whereby the article or category of article carrying each of the predetermined associations can be recognized and/or located.
• U.S. Pat. No. 4,660,025 describes a marker for use in an electronic surveillance system. The marker which can be in the form of a wire or strip of magnetic amorphous metal is characterized by having retained stress and a magnetic hysteresis loop with a large Barkhausen discontinuity. When the marker is exposed to an external magnetic field whose field strength, in the direction opposing the instantaneous magnetic polarization of the marker, exceeds a predetermined threshold value a regenerative reversal of the magnetic polarization of the marker occurs and results in the generation of a harmonically rich pulse that is readily detected and easily distinguished.
• U.S. Pat. No.5,175,419 describes a method for interrogating an identification tag comprised of a plurality of magnetic thin wires or thin bands which have highly rectangular hysteresis curves and different coercive forces. The wires or bands are preferably of amorphous material, but means for obtaining the highly rectangular hysteresis curves and different coercive forces are not taught; nor is the concept taught of using a time varying magnetic field superimposed on a ramp field for interrogation.
• U.S. Pat. No. 5,729,201 describes an inexpensive multibit magnetic tag is described which uses an array of amorphous wires in conjunction with a magnetic bias field. The tag is interrogated by the use of a ramped field or an ac field or a combination of the two. The magnetic bias is supplied either by coating each wire with a hard magnetic material which is magnetized or by using magnetized hard magnetic wires or foil strips in proximity to the amorphous wires. Each wire switches at a different value of the external interrogation field due to the differences in the magnetic bias field acting on each wire.
• The above identified U.S. Patents and the following related U.S. Patents assigned to the assignee of the present invention are hereby incorporated by reference: U.S. Pat. Nos. 5,528,222; 5,550,547; 5,552,778; 5,554,974; 5,538,803; 5,563,583; 5,565,847; 5,606,323; 5,521,601; 5,635,693; 5,673,037; 5,682,143: 5,680,106; 5,729,201; and 5,729,607. U.S. Patent applications assigned to the assignee of the present invention include: Ser. No. 08/303,965 filed Sep. 9, 1994 entitled RF Group Select Protocol, by Cesar et al.; Ser. No. 08/621,784, filed on Mar. 25, 1996 entitled “Thin Radio Frequency Transponder with Lead Frame” by Brady et al. (pending); Ser. No. 08/626,820, Filed: Apr. 3, 1996, entitled “Method of Transporting RF Power to Energize Radio Frequency Transponders” by Heinrich et al.; application submitted Aug. 9, 1996 entitled RFID System with Broadcast Capability by Cesar et al.; application submitted Jul. 29, 1996 entitled RFID transponder with Electronic Circuitry Enabling and Disabling Capability, by Heinrich et al.; Ser. No. 08/592,250; Ser. No. 08/496,838; Ser. No. 08/496,838; Ser. No. 08/909,719; Ser. No. 08/621,784,660,249; Ser. No. 08/660,261; Ser. No. 08/790,640; Ser. No. 08/790.639; and Ser. No. 08/681,742. The above identified U.S. Patents and U.S. Patent applications are hereby incorporated by reference.
SUMMARY OF THE INVENTION
• An RFID tag is combined with a magnetic EAS tag. The conducting elements of the RFID tag such as the antenna or the parasitic elements used to tune the antenna characteristics may be wholly or partially made from a non-linear magnetic material which produces a large signal in a magnetic EAS detection field. The non-linear magnetic material may be coated or electroplated or electrolessly plated with a good electrical conductor to enhance the antenna characteristics of the RFID tag. The non-linear magnetic material may be advantageously connected to dielectric material used to support and/or encapsulate the antenna and electronic components of the RFID tag.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 shows block diagram of an RF tag of the invention;
• FIG. 2 shows a block diagram of an RFID tag;
• FIG. 3 shows an elevation sketch of a physical layout for the sketch ofFIG. 2;
• FIG. 4 shows an alternative arrangement ofFIG. 2;
• FIG. 5 shows perspective sketch of a preferred alternative antenna arrangement for an RFID tag;
• FIG. 6 shows a perspective sketch of a patch antenna mounted coplanar with a non-linear magnetic material;
• FIG. 7 shows an elevation sketch of the apparatus ofFIG. 5; and
• FIG. 8 shows an elevation sketch of the apparatus ofFIG. 6 showing the supporting dielectric material.
DETAILED DESCRIPTION OF THE INVENTION
• FIG. 1 shows block diagram of anRF tag10 havingtag electronics12, atag memory14, and atag power supply16 connected to atag antenna18. Thetag antenna18 is shown in this embodiment made from a non-linearmagnetic material17. Such non-linear magnetic materials may have electrical conductivity insufficient for high quality antennas, and an alternative most preferred embodiment is to coat the non-linear magnetic material with a goodelectrical conducting material19 such as copper, gold, or a conducting polymer. The conductingmaterial19 need only be as thick as the skin depth of the high frequency RF signals sent to theRFID tag10. Such conductingmaterial19 may be coated on the non-linearmagnetic material17 by coating processes well known in the art such as evaporation, electroplating, or electroless plating.
• FIG. 2 shows a sketch of anRFID tag10 having atag antenna18 electrically and spatially separated from a non-linearmagnetic material17. In the embodiment shown, the non-linear material is shown as a wire placed as a parasitic element to adipole antenna18 of theRFID tag10. A preferred embodiment in this case also is to have thenon-linear material17 coated with an electrically conducting material if the electrical resistivity of thenon-linear material17 is too high.
• FIG. 3 shows an elevation sketch of a physical layout for the sketch ofFIG. 2. Thedipole antenna18 is connected to asilicon chip34 containing the tag memory, tag electronics, and tag power supply bywires36 and38. Theantenna18 and thechip34 are mounted on adielectric material32. Thenon-linear material17 is mounted on the opposite side of thedielectric material32 to theantenna18 andchip34. In this embodiment, thenon-linear material17 may once again be coated with a good electrical conductor.
• FIG. 4 shows an alternative arrangement ofFIG. 2. Thesilicon chip34, theantenna18, and thenon-linear material17 are all mounted on the same side of a supporting structure made ofdielectric32. In this embodiment thenon-linear material17 may once again preferrably be coated with a good electrical conductor.
• FIG. 5 shows perspective sketch of a preferred alternative antenna arrangement for an RFID tag. Asilicon chip34 is electrically attached to an electriallyconducting patch antenna50. The silicon chip is also electrically attached to an electrically conductingground plane52, which is spatially separated from thepatch antenna50 by a dielectric material (not shown). In the embodiment shown inFIG. 5, the electrically conductingground plane52 is made from non-linearmagnetic material17. In this embodiment, thenon-linear material17 may once again preferrably be coated with a good electrical conductor
• FIG. 6 shows a perspective sketch of a patch antenna mounted coplanar with a non-linearmagnetic material17. The magnetic material may be in the form of a wire or in the form of a sheet as shown in the diagram.
• FIG. 7 shows an elevation sketch of the apparatus ofFIG. 5. In this case, thedielectric material32 supporting the patch antenna, thechip34, and theground plane52 is explicitly shown. The alternative embodiment having a conductingmaterial19 coating the non-linear material is also shown. In this case, the material of thepatch antenna50 is alternatively made of a non-linear magnetic material instead of theground plane52. Once again, thenon-linear material17 may once again preferably be coated with a good electrical conductor
• FIG. 8 shows an elevation sketch of the apparatus ofFIG. 6 showing the supportingdielectric material32.

Claims (20)

1. A system for anti-theft protection and article identification, comprising

a transponder having an anti-theft portion for signaling the status of the article; and

an article identification portion for providing coded article information.

2. The system ofclaim 1, wherein the article identification portion is associated with an article, and communicates with a database to provide information concerning the identity of the article.

3. The system ofclaim 1, wherein the anti-theft portion communicates information indicating whether or not a given article has been paid for.

4. The system ofclaim 1, further comprising an interrogator for interrogating the transponder to obtain status and article identification information

5. The method of monitoring the movement of items, which comprises

associating a transponder with each of the items which transponder is operative to supply status and identity information for the associated item in response to interrogation thereof; and

interrogating the transponder to obtain both status and identity information therefrom for the associated item.

6. The method ofclaim 5, wherein the status information indicates whether or not a given item has been paid for, so that the identity information is available to identify the frequency of attempted theft for a given item.

7. The method ofclaim 5, wherein the interrogating step comprises applying a radio frequency field to the transponder.

8. The method ofclaim 7, wherein the transponder has a circuit which is generally resonant at the frequency of the radio frequency field.

9. The method ofclaim 7, further comprising applying an auxiliary field to the transponder.

10. The method ofclaim 9, wherein the auxiliary field is a magnetic field.

11. The method ofclaim 9, wherein the auxiliary field is an electromagnetic field.

12. A transponder comprising:

an anti-theft portion: and

an article identification portion.

13. The transponder ofclaim 12, wherein the article identification portion is associated with an article, and communicates with a database to provide information concerning the identity of the article.

14. The transponder ofclaim 12, wherein the anti-theft portion supplies status information in response to an interrogating field.

15. The transponder ofclaim 12, wherein the transponder is subjected to a radio frequency field.

16. The transponder ofclaim 15, wherein the transponder has a circuit which is generally resonant at the frequency of the radio frequency field.

17. The transponder ofclaim 15, wherein the transponder is further subjected to an auxiliary field.

18. The transponder ofclaim 15, wherein the transponder is further subjected to a magnetic field.

19. The transponder ofclaim 15, wherein the transponder is further subjected to an electromagnetic field.

20. The transponder ofclaim 15, wherein the transponder is further subjected to an acoustic energy field.

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