WO1989009983A1 - Antipilferage systems - Google Patents
Antipilferage systems Download PDFInfo
- Publication number
- WO1989009983A1 WO1989009983A1 PCT/GB1989/000164 GB8900164W WO8909983A1 WO 1989009983 A1 WO1989009983 A1 WO 1989009983A1 GB 8900164 W GB8900164 W GB 8900164W WO 8909983 A1 WO8909983 A1 WO 8909983A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- coil
- field generator
- magnetic field
- coils
- wound
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2405—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used
- G08B13/2408—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used using ferromagnetic tags
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2428—Tag details
- G08B13/2437—Tag layered structure, processes for making layered tags
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2428—Tag details
- G08B13/2437—Tag layered structure, processes for making layered tags
- G08B13/2442—Tag materials and material properties thereof, e.g. magnetic material details
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F5/00—Coils
- H01F5/003—Printed circuit coils
Definitions
- This invention relates to antipiiferage systems and to devices for use therein.
- Antipiiferage tags or markers are applied to 5 articles of commerce in order to protect them from theft at the point of sale premises.
- the tag is a magnetic medium which is deactivated when a shop assistant carries out the routine procedure at the time of effecting a sale. Such deactivation prevents 0 detection of the magnetic tag when it (and the article to which it is attached) pass through a detection system, typically in the form of a walk-through framework which emits an alternating magnetic interrogation field. This field is designed to interact with a tag and to respond
- 25 axis of the tag needs to be aligned perpendicularly with respect to the plane of the coils (i.e. along the coil axis) which produce the interrogating field if the tag is to be detected. Consequently, it is by no means unusual for the antipiiferage system to fail to detect certain
- an interrogating system for use in an antipilferage system, which is characterised in that the interrogating system comprises a magnetic field generator which is in the form of a substantially planar spirally wound coil or of a coil which is wound so as to approximate to a spiral.
- the system preferably also includes means tor detecting the response of a magnetic tag positioned within the effective field generated by said magnetic field generator, said detection means comprising one or more pairs of coils wound spirally or wound so as to approximate to a spiral winding, and positioned so as to overlay the magnetic field generator coil.
- Such overlay should preferably be exactly symmetrical and the phasing of the windings such that the net signal coupled directly from the field generator coil is near to zero.
- This arrangement greatly simplifies the filtering normally required at the receiver input to prevent overloading by directly coupled signals. It also enables the overall sensitivity to be tailored such that it is similar for labels in any orientation.
- the magnetic field generator co l and/or the detection coils are formed by photolithographic techniques such as are used in the production of printed circuit boards.
- a coil assembly An arrangement of generator coil and detection coils is hereinafter referred to as a coil assembly.
- the whole system is preferably constructed as an array of such coil assemblies which, in use, is positioned close to a point of sale such that customers and/or items to be checked will pass close to the array.
- a hand-held unit based on a single coil assembly is moved over the person to locate any concealed items carrying non-deactivated tags.
- spiral is not restricted to circular spirals, but also encompasses within its scope square, rectangular, oval and other simple spiral arrangements as well as more complicated Q shapes, provided that there is substantial adjacency in a common plane between successive turns or courses of the winding.
- a magnetic tag which has not been deactivated Q III give a response regardless of its orientation with respect to the device, at least at one point in a plane parallel to the surface of the spiral. It is thus possible to configure ad acent rows of suitably dimensioned coil assemblies such that a tag in any 5orientation which moves in a plane parallel to the array will be detected at some point (s) in its travel over the plane.
- a single coil assembly will detect a tag in any orientation if it is scanned in a suitable fashion in a plane parallel to that in which the tag lies.
- a suitable scan would be a simple meander with dimensions of the same order as the coil dimensions.
- Figure 1 is a plan view ot a spirally wound emitter coil
- Figure 2 is a plan view of spirally wound detector coils.
- each coil assembly comprises a generator coil 1 as shown in Figure 1 which is formed by photolithographic techniques as a planar spiral on a card 2 and two detector coils 3a, 3b arranged on the other side of the card 2 so as to overlay the generator coil 1.
- Each detector coil is similarly formed as a planar spiral.
- One particular type ot EAS label utilises a strip of amorphous ferromagnetic alloy about 30cm long.
- a coil assembly with a total dimension of 160mm x 160mm x 1mm thick, with about 30 turns in the emitting coil, and 2 x 60 turns in the detecting coil has been fabricated from double sided copper-clad fibre-glass printed circuit board.
- a processing system based on detection of high-order harmonics of a low level 5KHz interrogating field, and simple band-pass filtering, detection of labels in all orientations at a maximum distance of 100 +-*- ⁇ mm has been demonstrated.
Abstract
An antipilferage system for the detection of magnetic tags comprises an assembly (2) of spirally wound emitter (1) and/or detector (39, 36) coils. This arrangement enables a tag to be detected regardless of its orientation.
Description
1 ANTIPILFERAGE SYSTEMS
This invention relates to antipiiferage systems and to devices for use therein.
Antipiiferage tags or markers are applied to 5 articles of commerce in order to protect them from theft at the point of sale premises. Typically, the tag is a magnetic medium which is deactivated when a shop assistant carries out the routine procedure at the time of effecting a sale. Such deactivation prevents 0 detection of the magnetic tag when it (and the article to which it is attached) pass through a detection system, typically in the form of a walk-through framework which emits an alternating magnetic interrogation field. This field is designed to interact with a tag and to respond
15 by, for example, emitting a warning signal in the event that detection of a non-deactivated tag occurs.
A problem which occurs frequently with conventional antipiiferage systems is that an adequate detection signal is only available if a non-deactivated
20 tag passes through the interrogation gate in the correct orientation. Normal interrogating gates contain coils which generate a magnetic field principally along the axis of the coil. The magnetic tags are also usually unidirectiona iy sensitive. Thus generally, the major
25 axis of the tag needs to be aligned perpendicularly with respect to the plane of the coils (i.e. along the coil axis) which produce the interrogating field if the tag is to be detected. Consequently, it is by no means unusual for the antipiiferage system to fail to detect certain
3° items which are removed from the store without first having gone through the proper sales procedure simply because of the orientation of the tag on the article as it is moved through the interrogating field.
We have now devised an alternative to the usual
-■ --' interrogating gate system as employed at or near the point of sale in stores. The principal element of this
alternative system can be constructed as a walk-through framework, or as a hand-held item, the net response of which which is not orientation-dependent. More particularly, according to one aspect of the present invention, there is provided an interrogating system for use in an antipilferage system, which is characterised in that the interrogating system comprises a magnetic field generator which is in the form of a substantially planar spirally wound coil or of a coil which is wound so as to approximate to a spiral. The system preferably also includes means tor detecting the response of a magnetic tag positioned within the effective field generated by said magnetic field generator, said detection means comprising one or more pairs of coils wound spirally or wound so as to approximate to a spiral winding, and positioned so as to overlay the magnetic field generator coil. Such overlay should preferably be exactly symmetrical and the phasing of the windings such that the net signal coupled directly from the field generator coil is near to zero. This arrangement greatly simplifies the filtering normally required at the receiver input to prevent overloading by directly coupled signals. It also enables the overall sensitivity to be tailored such that it is similar for labels in any orientation. Preferably, the magnetic field generator co l and/or the detection coils are formed by photolithographic techniques such as are used in the production of printed circuit boards. The use of these techniques allows very precise mutual orientation between the emitting coil (on one side of the card or device) and the detecting coils (on the other side of the card or device). An arrangement of generator coil and detection coils is hereinafter referred to as a coil assembly.
The whole system is preferably constructed as an array of such coil assemblies which, in use, is positioned close to a point of sale such that customers
and/or items to be checked will pass close to the array. Alternatively, a hand-held unit based on a single coil assembly (magnetic field generator coil and detection coils) is moved over the person to locate any concealed items carrying non-deactivated tags.
As used herein, the term "spiral" is not restricted to circular spirals, but also encompasses within its scope square, rectangular, oval and other simple spiral arrangements as well as more complicated Q shapes, provided that there is substantial adjacency in a common plane between successive turns or courses of the winding.
One particular advantage of a flat spiral coil configuration in accordance with this invention over a 5conventional pile-wound coil of constant radius is its ease of automated manufacture. Another important advantage is that there is an improved magnetic field pattern. In particular, there is much less curvature of the principal component of the field pattern in the area o immediately above the windings. This improves the maximum coupling possible between the coils and a magnetic label in the vicinity of the coils. Since the overall sensitivity pattern of a generator/detector coil pair depends on their mutual arrangement, it is easy to 5arrange the areas and the overlaps of the two spiral windings to produce similar sensitivities for magnetic labels in any orientation.
With a detection device in accordance with this invention, a magnetic tag which has not been deactivated Q III give a response regardless of its orientation with respect to the device, at least at one point in a plane parallel to the surface of the spiral. It is thus possible to configure ad acent rows of suitably dimensioned coil assemblies such that a tag in any 5orientation which moves in a plane parallel to the array will be detected at some point (s) in its travel over the plane.
In those embodiments of the invention which take the form of a hand-held device, a single coil assembly will detect a tag in any orientation if it is scanned in a suitable fashion in a plane parallel to that in which the tag lies. A suitable scan would be a simple meander with dimensions of the same order as the coil dimensions. An exemplary embodiment of the present invention is shown in the accompanying drawings, in which:
Figure 1 is a plan view ot a spirally wound emitter coil; and
Figure 2 is a plan view of spirally wound detector coils.
In the preferred embodiment each coil assembly comprises a generator coil 1 as shown in Figure 1 which is formed by photolithographic techniques as a planar spiral on a card 2 and two detector coils 3a, 3b arranged on the other side of the card 2 so as to overlay the generator coil 1. Each detector coil is similarly formed as a planar spiral. One particular type ot EAS label utilises a strip of amorphous ferromagnetic alloy about 30cm long. For a hand-held detector application a coil assembly with a total dimension of 160mm x 160mm x 1mm thick, with about 30 turns in the emitting coil, and 2 x 60 turns in the detecting coil has been fabricated from double sided copper-clad fibre-glass printed circuit board. Using a processing system based on detection of high-order harmonics of a low level 5KHz interrogating field, and simple band-pass filtering, detection of labels in all orientations at a maximum distance of 100 +-*-ϋmm has been demonstrated.
Claims
1. An interrogating system for use in an antipilferage system, characterised in that the interrogating system comprises a magnetic field generator
5 which is in the form of a substantially planar spirally wound coil or of a coil which is wound so as to approximate to a spiral.
2. A system as claimed in claim 1 which includes means for detecting the response of a magnetic tag 0 positioned within the effective field generated by said magnetic field generator, said detection means comprising one or more pairs of coils wound spirally or wound so as to approximate to a spiral winding, and positioned so as to overlay the magnetic field generator coil. 5
3. A system as claimed in claim 2 in which said overlay is exactly symmetrical and the phasing of the windings is such that the net signal coupled directly from the field generator coil is near to zero.
4. A system as claimed in any preceding claim in 0 which the magnetic field generator coil and/or the detection coils, when present, are formed by photolithographic techniques.
5. A system as claimed in any preceding claim which is constructed as an array of such coils and which, in use, is positioned close to a point of sale such that customers and/or items to be checked will pass close to the array.
6. A system as claimed in any of claims 1 to 4 which comprises a hand-held unit based on a single coil 0 assembly of magnetic field generator coil and detection coils.
i>
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BR898906849A BR8906849A (en) | 1988-04-15 | 1989-02-20 | INTERROGATION SYSTEM FOR USE IN AN ANTI-THEFT SYSTEM |
NO89895036A NO895036L (en) | 1988-04-15 | 1989-12-14 | Antipilferage SYSTEMS. |
DK637089A DK637089A (en) | 1988-04-15 | 1989-12-15 | THEFT INSURANCE SYSTEM |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB888808933A GB8808933D0 (en) | 1988-04-15 | 1988-04-15 | Antipilferage system |
GB8808933.9 | 1988-04-15 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1989009983A1 true WO1989009983A1 (en) | 1989-10-19 |
Family
ID=10635253
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB1989/000164 WO1989009983A1 (en) | 1988-04-15 | 1989-02-20 | Antipilferage systems |
Country Status (12)
Country | Link |
---|---|
US (1) | US5049856A (en) |
EP (1) | EP0338660B1 (en) |
JP (1) | JP2604477B2 (en) |
AT (1) | ATE95930T1 (en) |
AU (1) | AU608431B2 (en) |
BR (1) | BR8906849A (en) |
CA (1) | CA1295030C (en) |
DE (1) | DE68909830T2 (en) |
DK (1) | DK637089A (en) |
GB (1) | GB8808933D0 (en) |
NO (1) | NO895036L (en) |
WO (1) | WO1989009983A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2333666A (en) * | 1998-01-15 | 1999-07-28 | Morton Frazer Roseman | An authentication system using magnetic markers with a feedback system to control the magnetic reader field |
Families Citing this family (17)
Publication number | Priority date | Publication date | Assignee | Title |
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FR2662320B1 (en) * | 1990-05-18 | 1994-05-13 | Cemagref | CONTACTLESS CONNECTION DEVICE FOR CONNECTING SERIES BUS LINES. |
JPH04245410A (en) * | 1991-01-30 | 1992-09-02 | Sharp Corp | Printed coil for double-tuned circuit use |
DE69330265T2 (en) * | 1992-11-25 | 2002-02-07 | Simmonds Precision Products | Data processing structures and methods |
GB9305085D0 (en) * | 1993-03-12 | 1993-04-28 | Esselte Meto Int Gmbh | Electronic article surveillance system with enhanced geometric arrangement |
US5602540A (en) * | 1993-06-14 | 1997-02-11 | Simmonds Precision Products Inc. | Fluid gauging apparatus with inductive interrogation |
US5433115A (en) * | 1993-06-14 | 1995-07-18 | Simmonds Precision Products, Inc. | Contactless interrogation of sensors for smart structures |
US5515041A (en) * | 1993-06-14 | 1996-05-07 | Simmonds Precision Products Inc. | Composite shaft monitoring system |
US5581248A (en) * | 1993-06-14 | 1996-12-03 | Simmonds Precision Products, Inc. | Embeddable device for contactless interrogation of sensors for smart structures |
DE19503896A1 (en) * | 1995-02-07 | 1996-08-08 | Esselte Meto Int Gmbh | Device for detecting an article provided with an electronic security element |
US5508684A (en) * | 1995-03-02 | 1996-04-16 | Becker; Richard S. | Article tag |
US5717381A (en) * | 1995-12-21 | 1998-02-10 | Eastman Kodak Company | Copyright protection for photos and documents using magnetic elements |
US6060988A (en) * | 1997-02-03 | 2000-05-09 | Sensormatic Electronics Corporation | EAS marker deactivation device having core-wound energized coils |
US5867101A (en) * | 1997-02-03 | 1999-02-02 | Sensormatic Electronics Corporation | Multi-phase mode multiple coil distance deactivator for magnetomechanical EAS markers |
GB9815118D0 (en) * | 1998-07-14 | 1998-09-09 | Clan Holdings Ltd | Security tag |
EP1195714A1 (en) * | 2000-10-04 | 2002-04-10 | Sokymat S.A. | Transponder unit |
US20060180094A1 (en) * | 2005-02-15 | 2006-08-17 | Viggiano Gregory R | Pet containment apparatus and method |
KR102257892B1 (en) * | 2014-11-26 | 2021-05-28 | 삼성전자주식회사 | Advanced NFC Antenna and Electronic Device with the same |
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Publication number | Priority date | Publication date | Assignee | Title |
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DE2823191A1 (en) * | 1977-05-24 | 1978-11-30 | Minnesota Mining & Mfg | IMPROVED SYSTEM FOR THEFT PROTECTION WITH EIGHT-SHAPED FIELD AND DETECTOR COILS |
US4263553A (en) * | 1978-05-30 | 1981-04-21 | Cook Kenneth M | Discriminating metal detector with compensation for ground minerals |
EP0130286A2 (en) * | 1983-06-30 | 1985-01-09 | Knogo Corporation | Method and apparatus for detection of targets in an interrogation zone |
EP0142380A2 (en) * | 1983-11-16 | 1985-05-22 | Minnesota Mining And Manufacturing Company | Electronic article surveillance system using marker containing a distributed capacitance lc resonant circuit |
EP0189592A1 (en) * | 1985-01-07 | 1986-08-06 | Identitech Corporation | Coplanar antenna for proximate surveillance systems |
US4613843A (en) * | 1984-10-22 | 1986-09-23 | Ford Motor Company | Planar coil magnetic transducer |
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-
1988
- 1988-04-15 GB GB888808933A patent/GB8808933D0/en active Pending
-
1989
- 1989-02-20 AU AU32881/89A patent/AU608431B2/en not_active Ceased
- 1989-02-20 JP JP1503225A patent/JP2604477B2/en not_active Expired - Fee Related
- 1989-02-20 AT AT89301644T patent/ATE95930T1/en not_active IP Right Cessation
- 1989-02-20 EP EP89301644A patent/EP0338660B1/en not_active Expired - Lifetime
- 1989-02-20 DE DE89301644T patent/DE68909830T2/en not_active Expired - Fee Related
- 1989-02-20 BR BR898906849A patent/BR8906849A/en unknown
- 1989-02-20 WO PCT/GB1989/000164 patent/WO1989009983A1/en unknown
- 1989-02-21 CA CA000591687A patent/CA1295030C/en not_active Expired - Lifetime
- 1989-12-04 US US07/445,765 patent/US5049856A/en not_active Expired - Lifetime
- 1989-12-14 NO NO89895036A patent/NO895036L/en unknown
- 1989-12-15 DK DK637089A patent/DK637089A/en not_active Application Discontinuation
Patent Citations (6)
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DE2823191A1 (en) * | 1977-05-24 | 1978-11-30 | Minnesota Mining & Mfg | IMPROVED SYSTEM FOR THEFT PROTECTION WITH EIGHT-SHAPED FIELD AND DETECTOR COILS |
US4263553A (en) * | 1978-05-30 | 1981-04-21 | Cook Kenneth M | Discriminating metal detector with compensation for ground minerals |
EP0130286A2 (en) * | 1983-06-30 | 1985-01-09 | Knogo Corporation | Method and apparatus for detection of targets in an interrogation zone |
EP0142380A2 (en) * | 1983-11-16 | 1985-05-22 | Minnesota Mining And Manufacturing Company | Electronic article surveillance system using marker containing a distributed capacitance lc resonant circuit |
US4613843A (en) * | 1984-10-22 | 1986-09-23 | Ford Motor Company | Planar coil magnetic transducer |
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GB2333666A (en) * | 1998-01-15 | 1999-07-28 | Morton Frazer Roseman | An authentication system using magnetic markers with a feedback system to control the magnetic reader field |
Also Published As
Publication number | Publication date |
---|---|
GB8808933D0 (en) | 1988-05-18 |
DE68909830T2 (en) | 1994-02-10 |
US5049856A (en) | 1991-09-17 |
BR8906849A (en) | 1990-12-04 |
AU3288189A (en) | 1989-11-03 |
ATE95930T1 (en) | 1993-10-15 |
AU608431B2 (en) | 1991-03-28 |
DE68909830D1 (en) | 1993-11-18 |
JP2604477B2 (en) | 1997-04-30 |
NO895036D0 (en) | 1989-12-14 |
DK637089D0 (en) | 1989-12-15 |
JPH02504438A (en) | 1990-12-13 |
EP0338660B1 (en) | 1993-10-13 |
DK637089A (en) | 1989-12-15 |
CA1295030C (en) | 1992-01-28 |
EP0338660A1 (en) | 1989-10-25 |
NO895036L (en) | 1989-12-14 |
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