EP0604293B1 - Etiquette à couche mince à double état pour la surveillance électronique d'articles - Google Patents

Etiquette à couche mince à double état pour la surveillance électronique d'articles Download PDF

Info

Publication number
EP0604293B1
EP0604293B1 EP19930403099 EP93403099A EP0604293B1 EP 0604293 B1 EP0604293 B1 EP 0604293B1 EP 19930403099 EP19930403099 EP 19930403099 EP 93403099 A EP93403099 A EP 93403099A EP 0604293 B1 EP0604293 B1 EP 0604293B1
Authority
EP
European Patent Office
Prior art keywords
thin
film
signal
marker
films
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19930403099
Other languages
German (de)
English (en)
Other versions
EP0604293A1 (fr
Inventor
Ching-Long C/O Minnesota Mining And Tsai
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Co
Original Assignee
Minnesota Mining and Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Minnesota Mining and Manufacturing Co filed Critical Minnesota Mining and Manufacturing Co
Publication of EP0604293A1 publication Critical patent/EP0604293A1/fr
Application granted granted Critical
Publication of EP0604293B1 publication Critical patent/EP0604293B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • G08B13/2411—Tag deactivation
    • 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

Definitions

  • the invention relates to reversibly reactivatable dual status markers useful in magnetic-type electronic article surveillance (EAS) systems.
  • EAS electronic article surveillance
  • an article bearing one of those markers is passed through an interrogation zone of alternating magnetic fields, the magnetization state of the marker is periodically reversed, and a remotely detectable characteristic response (here sometimes called "an alarm signal") is produced.
  • the invention also relates to the manufacture of such markers and to a product that can be used as a control element to afford dual status to a marker of the prior art.
  • Magnetic-type EAS systems are widely used to inhibit the theft of merchandise such as clothing, books, and cassettes.
  • Markers used in such systems typically have comprised elongated ribbons of metal foil that exhibit high permeability and low coercive force to enable their state of magnetization to reverse in the relatively low intensity alternating magnetic fields typically associated with magnetic-type EAS systems.
  • Those fields have average peak intensities of a few Oersteds, typically ranging from about one Oersted at the center to about 20 Oersteds at the edges of the interrogation zone of an EAS system.
  • a remanently magnetizable layer is laminated to such a ribbon and acts as a control element to afford dual status to the marker. It has a passive status when the remanently magnetizable layer is magnetized to prevent the marker from producing an alarm signal when an article to which it is attached is carried through an interrogation zone of an EAS system. It has a sensitized status when the remanently magnetizable layer is demagnetized, thus enabling the marker to produce an alarm signal.
  • the Elder patent also suggests that a disc-shaped marker, which is sufficiently thin, can have a useful demagnetization factor.
  • the marker of Montean '908 also can be bidirectional. It has a specially shaped foil which bears a remanently magnetizable layer that, when magnetized in a predetermined pattern, permits the marker to produce an alarm signal in an interrogation zone. When the remanently magnetizable layer is demagnetized, the marker will not produce an alarm signal.
  • U.S. Patent No. 4,960,651 points out that a marker, when sensitized, should have low demagnetization factors to permit low intensity interrogation fields to be used, and that metal ribbons such as ribbons of permalloy foil must be quite long to achieve low demagnetization factors.
  • the Pettigrew patent concerns a marker that has low demagnetization factors and is made by depositing onto a substrate a magnetic thin-film of low coercive force and high permeability that preferably is from 1 to 5 ⁇ m in thickness.
  • the Pettigrew thin-film marker can be quite thin and more mechanically flexible and hence more robust. By being thin, it can be less conspicuous. Also, it can have a more convenient shape such as the dimension and shape of a price label and can be square or circular.
  • the Pettigrew marker can be made to have dual status by applying a deactivation layer of semi-hard magnetic material to change the effective magnetic properties of the magnetic thin-film of low coercive force so that it is not recognized in an interrogation zone.
  • the deactivation layer employed a thin sheet (col. 15, line 9) or a foil, slurry, needles, or steel wool or mesh (col. 16, lines 15-24).
  • the Pettigrew patent does suggest: "The deactivating material may be fabricated by thin film processes" (col. 6, lines 62-64) but includes no enabling disclosure, instead referring to disclosure for fabricating the magnetic thin-films of low coercivity.
  • an elongated marker may be formed of a strip of alternating sputtered layers of ferromagnetic materials. In that construction, each layer is separated by an evaporated coating of, for example, aluminum oxide. Fearon still emphasizes the necessity of an elongated shape and the subsequent need for appropriate orientation in an interrogation field. See also U.S. Pat. No. 4,682,154 (Fearon).
  • the marker of coassigned U.S. Patent No. 5,083,112 (Piotrowski et al.) comprises a laminate of a plurality of magnetic thin-films deposited on a flexible substrate with an ultrathin nonmagnetic thin-film interposed between adjacent magnetic thin-films.
  • Each of the magnetic thin-films exhibits high permeability and a coercive force sufficiently low so as not to retain any given magnetization state and less than the average intensity of magnetic fields encountered in an interrogation zone, such that upon exposure to such fields, the magnetization state of the marker is periodically reversed and an alarm signal is produced.
  • the easy axis of one of the magnetic thin-films extends in a direction different from that of another (as in Fig. 3) or a magnetic thin-film has more than one easy axis, the marker is bi-directional.
  • the Piotrowski patent demonstrates that a plurality of magnetic thin-films permit the markers to be smaller and yet produce sharper, more intense signals than was possible in the prior art. Its five examples employ from 7 to 15 pairs of magnetic thin-films (e.g., Ni-Fe) and nonmagnetic thin-films (e.g., SiO x ).
  • the Piotrowski marker can include a layer of remanently magnetizable material such as a thin foil of magnetic stainless steel or vicalloy or a dispersion of gamma iron oxide particles.
  • the invention provides a reversibly reactivatable dual status marker for use with a magnetic-type EAS system that produces, in an interrogation zone, alternating magnetic fields having average peak intensities of a few Oersteds.
  • the dual status marker the invention should be as economical to manufacture as any prior marker, and should be at least as small in area and thinner, more flexible, and more durable than any above-discussed marker without any reduction in performance.
  • the novel marker should function well at thicknesses that are so thin that it can be virtually undetectable when hidden between layers of some garments. As was pointed out in the Montean Patent No.
  • the dual status marker of the invention has a substrate and, supported by the substrate, a signal-producing layer and a signal-blocking layer.
  • the signal-producing layer includes at least one magnetic thin-film having high permeability and a coercive force less than the minimum peak intensity encountered in said zone, such that upon exposure to fields of an interrogation zone, the magnetization state of said at least one magnetic thin-film is periodically reversed and a remotely detectable characteristic response (i.e., an alarm signal) is produced.
  • Said at least one magnetic thin-film should have a total thickness of from 200 to 1000 nm. At total thicknesses substantially below 200 nm, a marker might fail to produce an alarm signal in some magnetic-type EAS systems, while total thicknesses substantially above 1000 nm would increase the cost of the marker without significant benefit.
  • the signal-blocking layer of the novel marker includes at least one remanently magnetizable thin-film having a total thickness at least equal to the total thickness of said at least one magnetic thin-film of the signal-producing layer.
  • the signal-blocking layer should be in substantial contact with and extend over an area of the signal-producing layer and should have a size and coercivity sufficient to prevent the signal-producing layer from producing an alarm signal in the interrogation zone when the signal-blocking layer is magnetized.
  • the novel marker can be produced at reasonable cost.
  • the coercivity of the signal-blocking layer does not exceed 100 oersteds so that it can be demagnetized by a magnetic field that is weak enough not to damage any article to which a marker may be attached, e.g., not to erase any data on the magnetic tape of a cassette.
  • the coercivity of the signal-blocking layer is at least 25 Oersteds to guard against accidental demagnetization or remagnetization.
  • the signal-blocking layer of the novel marker should have adequate thickness to provide enough magnetic flux, when magnetized, to saturate adjacent portions of the signal-producing layer.
  • the total thickness of said at least one remanently magnetizable thin-film preferably is from two to five times the total thickness of said at least one magnetic thin-film of the signal-producing layer.
  • said at least one magnetic thin-film preferably has a total thickness of from 200 to 500 nm, and said at least one remanently magnetizable thin-film is from 800 to 1200 nm in total thickness.
  • electrically conductive, remanently magnetizable thin-films could propagate eddy currents when subjected to interrogating fields of high frequency, and so might have an undesirable shielding effect when demagnetized. Interrogating fields of higher frequency enable a signal-producing layer of the novel marker to produce alarm signals of greater amplitude.
  • the signal-blocking layer has from 3 to 11 pairs of remanently magnetizable thin-films and interposed nonmagnetic thin-films.
  • the novel marker When its signal-producing layer comprises a single magnetic thin-film, the novel marker can produce a signal that is sufficiently sharp and intense to produce alarm signals in most magnetic-type EAS systems now on the market.
  • the signal-producing layer comprises a plurality of magnetic thin-films and interposed nonmagnetic thin-films, the novel marker can produce a sharper, more intense and hence more reliable signal.
  • Preferred magnetic thin-film materials for the signal-producing layer include permalloy, "Sendust,” and amorphous magnetic alloys such as are listed in Re. 32,427 (Gregor et al.) at col. 6, lines 11-18.
  • the signal-blocking layer is in intimate contact with the signal-producing layer so that when the signal blocking layer is magnetized, its magnetic flux is efficiently shunted through the signal-producing layer.
  • an ultrathin nonmagnetic thin-film layer it may be desirable to interpose an ultrathin nonmagnetic thin-film layer. Any such ultrathin nonmagnetic thin-film that is either interposed between the signal-producing and signal-blocking layers, or is interposed between a plurality of magnetic thin-films of the signal-producing layer, should be thinner than the thin-films it is separating and should be as thin as possible, such as from 5 to 20 nm.
  • Remanently magnetizable materials that have been most effective for the signal-blocking layer are Fe-Cr alloys having a Cr content up to about 20 atomic percent. Preferably, the Cr content is from 1 to 15 atomic percent to afford a coercivity of from 25 to 100 Oersteds.
  • Other useful remanently magnetizable materials include Fe-Co-Cr, Fe-Ni-Cr, and Ni-Co alloys and partially oxidized Ni-Fe alloys.
  • Ultrathin nonmagnetic thin-films may be readily formed from an oxide of silicon, aluminum, or the like.
  • Each of the nonmagnetic thin-films, magnetic thin-films of the signal-producing layer, and remanently magnetizable thin-films of the signal-blocking layer can be formed by evaporation, sputtering, sublimation, etc.
  • the signal-blocking layer of the thin-film of the novel dual status marker preferably is discontinuous or, if continuous, is magnetized in an alternating pole pattern by a device such as that of Fig. 23 of Montean Pat. No. 4,746,908, thus better ensuring deactivation of said at least one magnetic thin-film.
  • a discontinuous signal-blocking layer allows the novel marker to be magnetized in any magnetic-type EAS system now on the market, whereas a continuous signal-blocking layer might not become sufficiently demagnetized in apparatus of an EAS system that deactivates a marker by translating it across a unidirectional magnetic field.
  • a continuous signal-blocking layer can be made discontinuous by scoring, or a discontinuous thin-film or thin-films can be applied through masks.
  • Suitable discontinuous patterns are those of the magnetizable material 86 of Fig. 5 of the Piotrowski patent and the magnetizing elements 44 of Fig. 4 of the Gregor patent.
  • the segments of a discontinuous pattern are of substantially uniform size and shape and each has a area of from 1 to 100 mm 2 .
  • the substrate of the novel marker preferably is flexible, e.g., a polyimide or high-temperature-resistant polyester web from 25 to 50 ⁇ m thick. While polyimide has superb mechanical properties, including stability at elevated temperatures, it is highly hygroscopic, retaining about 1 percent by weight of water. It is necessary to outgas such films prior to deposition. Such outgassing has been obtained by passing the substrate films within a vacuum chamber three times at a rate of approximately 60 cm per minute over a roller heated to 315°C. For some applications, thin metallic foils of nonmagnetic stainless steel, aluminum, and copper can also be used.
  • the substrate can either become a permanent part of the novel marker, or the thin-films can be transferred from substrates to articles which are to be protected against theft, e.g., to the shell of a cassette. Upon doing so, it may be desirable to apply an opaque coating to make the marker invisible.
  • the novel marker can have a variety of shapes, such as the size and shape of a price label, and it can be square or circular.
  • its area preferably is at least 1 cm 2 , more preferably from 2 to 10 cm 2 .
  • said at least one magnetic thin-film preferably has a maximum differential permeability of at least 5,000 and a coercive force no greater that 5 Oersteds.
  • FIGS. 1-3 are schematic.
  • FIGS. 1-3 are schematic.
  • a dual status EAS marker 10 has a flexible substrate 12 bearing a magnetic thin-film 14 that has high permeability and low coercive force, e.g., permalloy, and serves as a signal-producing layer.
  • a remanently magnetizable thin-film 16 In contact and coterminous with the magnetic thin-film 14 is a remanently magnetizable thin-film 16 that serves as a signal-blocking layer.
  • the remanently magnetizable thin-film 16 has a discontinuous pattern of squares 18.
  • FIG. 3 shows a second dual status EAS marker 20 that has a flexible substrate 22 on which is deposited a signal-producing layer 23 including a plurality of magnetic thin-films 24, such as permalloy, and ultrathin nonmagnetic thin-films 25, such as SiO x , with an ultrathin nonmagnetic thin-film 25 interposed between adjacent magnetic thin-films 24.
  • a signal-producing layer 23 including a plurality of magnetic thin-films 24, such as permalloy, and ultrathin nonmagnetic thin-films 25, such as SiO x , with an ultrathin nonmagnetic thin-film 25 interposed between adjacent magnetic thin-films 24.
  • a nonmagnetic thin-film 26 In contact and coterminous with the outermost magnetic thin-film 24 is a nonmagnetic thin-film 26 which is covered by a continuous remanently magnetizable thin-film 27 that serves as a signal-blocking layer.
  • a line 30 indicates approximate coercivities of Fe-Cr alloys based on test values 32 on thin-films.
  • a dual status marker as shown in FIG. 3 was prepared using an ion beam sputtering/deposition unit and a glass substrate. Onto the glass substrate was deposited a coterminous thin-film of amorphous Co-based alloy to a thickness of 350 nm. This was then annealed at 350°C for 30 minutes in a unidirectional magnetic field having an intensity of 5 Oe along the plane of the thin-film. In an alternating magnetic field of 10 kHz and an amplitude of 2 Oe, a sample 2.5 cm square had
  • an ultrathin Si thin-film over which a signal-blocking layer was applied by depositing five thin-films of an Fe 90 -Cr 10 alloy interposed with four nonmagnetic Si thin-films, all of which were coterminous with the substrate.
  • the remanently magnetizable Fe-Cr thin films afforded dual status to the resulting marker.
  • Each of the Fe-Cr thin-films was 70 nm in thickness, and each of the ultrathin Si thin-films was 10 nm in thickness.
  • the signal-blocking layer was then magnetized to have 12 rows per inch (4.7 rows/cm) of oppositely-directed magnetized regions, thus preventing the marker from producing an alarm signal when exposed to the aforementioned magnetic field. In that field, the hysteresis curve of the signal-producing layer became a minor loop, resulting in a signal too low in harmonic content to be recognized as an alarm.
  • the dual status marker was tested in 3M's Model 3300B magnetic-type EAS system. When its signal-blocking layer was magnetized, the marker was passive and did not produce an alarm signal in the interrogation zone of the EAS system. When the signal-blocking layer was demagnetized, the magnetization state of the signal-producing layer was periodically reversed to produce an alarm signal.
  • a single remanently magnetizable thin-film of Fe 88 -Cr 12 alloy having a thickness of 2 ⁇ m was deposited by e-beam evaporation onto a polyimide ("Kapton") film 50 ⁇ m in thickness.
  • the resulting laminate was cut into squares, each 4.2 mm on a side.
  • a pressure-sensitive adhesive transfer film 25 ⁇ m in thickness the exposed faces of the squares were bonded to the outermost Ni-Fe thin-film of the signal-producing layer in the pattern of FIG. 2 of the drawing with a spacing of 2.1 mm between adjacent squares.
  • the segmented Fe-Cr signal-blocking layer of the resulting dual-status marker was magnetized by translating it across a unidirectional magnetic field.
  • the marker When tested in an EAS system as in Example 1 while its signal-blocking layer was magnetized, the marker was passive and did not produce an alarm signal in the interrogation zone.
  • the signal-blocking layer When the signal-blocking layer was demagnetized, the magnetization state of the signal-producing layer was periodically reversed to produce an alarm signal.
  • a dual status marker was prepared as disclosed in Example 2 except as indicated.
  • a polyimide (“Kapton”) film were sequentially deposited eleven layer pairs of magnetic thin-films of Ni-Fe alloy (each 35 nm in thickness) and nonmagnetic thin-films of SiO x (each 10 nm in thickness).
  • a sample 2.5 cm square had
  • Ni-Fe thin-film layer Onto the exposed Ni-Fe thin-film layer were deposited four layer pairs of remanently magnetizable thin-films of Fe 90 Cr 10 (each 100 nm in thickness) and nonmagnetic thin-films of CrO x (each 10 nm in thickness applied by reactive sputtering).
  • the continuous signal-blocking layer of the resulting dual-status marker was then magnetized as in Example 1, thus preventing the marker from producing an alarm signal when exposed to the aforementioned magnetic field.
  • the dual status marker was tested in 3M's Model 3300B magnetic-type EAS system. When its signal-blocking layer was magnetized, the marker was passive and did not produce an alarm signal in the interrogation zone of the EAS system. When the signal-blocking layer was demagnetized, the magnetization state of the signal-producing layer was periodically reversed to produce an alarm signal.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Computer Security & Cryptography (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Burglar Alarm Systems (AREA)
  • Thin Magnetic Films (AREA)

Claims (8)

  1. Etiquette à double état (20) destinée à être utilisée avec un système électronique de surveillance d'articles de type magnétique, ce système produisant dans une zone d'interrogation, des champs magnétiques alternatifs ayant des intensités de crête moyennes de quelques Oersted, ladite étiquette comprenant :
    un substrat (22) et, supportées par le substrat (22),
    (a) une couche de production de signal (23) comprenant au moins un film mince magnétique (24) ayant une haute perméabilité et une force coercitive inférieure aux intensités de crête moyenne rencontrées dans ladite zone, de façon que lors de l'exposition à ces champs, l'état de magnétisation de la couche de production de signal (23) soit périodiquement inversé et qu'un signal d'alarme soit produit, et
    (b) une couche de blocage de signal comprenant un film mince pouvant être magnétisé de façon rémanente (27), la couche de blocage de signal étant en contact sensible avec et s'étendant sur une zone de la couche de production de signal (23), et ayant une taille et une coercitivité suffisantes pour empêcher la couche de production de signal (23) d'envoyer un signal d'alarme dans la zone d'interrogation lorsque ledit film mince pouvant être magnétisé de façon rémanente (27) est magnétisé,
    caractérisé en ce que la couche de blocage de signal comprend une pluralité de films minces pouvant être magnétisés de façon rémanente (25) et un film mince non-magnétique extrêmement mince (26) intercalé entre les films minces adjacents pouvant être magnétisés de façon rémanente (27).
  2. Produit pouvant être utilisé pour désactiver une étiquette à double état comportant une couche de production de signal de haute perméabilité et de faible coercitivité qui produit un signal d'alarme lorsqu'un article portant l'étiquette traverse une zone d'interrogation d'un système électronique de surveillance d'articles de type magnétique, ledit produit comprenant :
    (a) un substrat (22) et, supportées par le substrat (22),
    (b) une couche de prévention comprenant un film mince pouvant être magnétisé de façon rémanente ayant une taille et une coercitivité telles que, lorsqu'elle est placée en contact sensible avec ladite couche de production de signal, elle empêche la couche de production de signal (23) de produire un signal d'alarme dans la zone d'interrogation lorsque ledit film mince pouvant être magnétisé de façon rémanente est magnétisé,
    caractérisé en ce que ladite couche de prévention comprend une pluralité de films minces pouvant être magnétisés de façon rémanente (25), et
    (c) un film mince non-magnétique extrêmement mince (26) intercalé entre les films minces adjacents pouvant être magnétisés de façon rémanente (27), ce film mince non-magnétique étant plus mince que l'un ou l'autre desdits films minces adjacents pouvant être magnétisés de façon rémanente.
  3. Etiquette à double état (20) selon la revendication 1 et comprenant en outre une pluralité desdits au moins un film magnétique mince (25) et un film mince non-magnétique extrêmement mince (25) intercalé entre les films minces adjacents desdits au moins un film mince magnétique, chacun des films minces non-magnétiques étant plus mince que chacun de ses films minces magnétiques adjacents.
  4. Etiquette à double état (20) selon la revendication 1, dans laquelle ledit au moins un film mince pouvant être magnétisé de façon rémanente (27) comprend un alliage Fe-Cr ayant un contenu en Cr allant jusqu'à 20% atomique.
  5. Etiquette à double état (20) selon la revendication 4, dans laquelle le contenu en Cr dudit au moins un film mince pouvant être magnétisé de façon rémanente (27) est de 1 à 15% atomique.
  6. Etiquette à double état (20) selon la revendication 1, dans laquelle ledit au moins un film mince pouvant être magnétisé de façon rémanente (27) a une épaisseur totale de 2 à 5 fois l'épaisseur totale dudit au moins un film magnétique (24).
  7. Etiquette à double état (20) selon la revendication 2, et la revendication 6, dans laquelle l'épaisseur totale dudit au moins un film mince pouvant être magnétisé de façon rémanente (27) est de 0,8 à 1,2 µm.
  8. Etiquette à double état (20) selon la revendication 1, dans laquelle ledit au moins un film mince pouvant être magnétisé de façon rémanente (27) est discontinu.
EP19930403099 1992-12-23 1993-12-20 Etiquette à couche mince à double état pour la surveillance électronique d'articles Expired - Lifetime EP0604293B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US99618292A 1992-12-23 1992-12-23
US996182 1992-12-23

Publications (2)

Publication Number Publication Date
EP0604293A1 EP0604293A1 (fr) 1994-06-29
EP0604293B1 true EP0604293B1 (fr) 2000-06-07

Family

ID=25542596

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19930403099 Expired - Lifetime EP0604293B1 (fr) 1992-12-23 1993-12-20 Etiquette à couche mince à double état pour la surveillance électronique d'articles

Country Status (6)

Country Link
EP (1) EP0604293B1 (fr)
JP (1) JPH06231376A (fr)
AU (1) AU669014B2 (fr)
CA (1) CA2109643C (fr)
DE (1) DE69328819T2 (fr)
ES (1) ES2148211T3 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0782013A3 (fr) * 1995-12-27 1998-08-12 Unitika Ltd. Marqueur magnétique
JPH09180936A (ja) * 1995-12-27 1997-07-11 Unitika Ltd 磁気素子
US5699047A (en) * 1996-01-19 1997-12-16 Minnesota Mining And Manufacturing Co. Electronic article surveillance markers for direct application to optically recorded media
JPH09232142A (ja) * 1996-02-28 1997-09-05 Unitika Ltd 磁気素子及びその製造方法
JP2002334307A (ja) * 2001-05-08 2002-11-22 Nhk Spring Co Ltd 合成樹脂成形体

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0295028B1 (fr) * 1987-06-08 1993-04-14 Esselte Meto International GmbH Dispositifs magnétiques
GB8900398D0 (en) * 1989-01-09 1989-03-08 Scient Generics Ltd Magnetic materials
US5368948A (en) * 1989-01-09 1994-11-29 Esselte Meto International Produktions Magnetic materials for security applications
US5015993A (en) * 1989-06-29 1991-05-14 Pitney Bowes Inc. Ferromagnetic alloys with high nickel content and high permeability
US5083112A (en) * 1990-06-01 1992-01-21 Minnesota Mining And Manufacturing Company Multi-layer thin-film eas marker

Also Published As

Publication number Publication date
CA2109643C (fr) 2002-03-26
JPH06231376A (ja) 1994-08-19
AU669014B2 (en) 1996-05-23
DE69328819T2 (de) 2000-12-28
AU5180793A (en) 1994-07-07
CA2109643A1 (fr) 1994-06-24
EP0604293A1 (fr) 1994-06-29
DE69328819D1 (de) 2000-07-13
ES2148211T3 (es) 2000-10-16

Similar Documents

Publication Publication Date Title
CA2041581C (fr) Marqueur en couches minces pour la surveillance electronique d'articles
EP0260831B1 (fr) Etiquette à pourvoir d'une image par voie magnétique et à double état pour la surveillance d'articles
US4956636A (en) E.A.S. tag having a control component with selectively magnetizeable regions
EP0295028B1 (fr) Dispositifs magnétiques
US4075618A (en) Magnetic asymmetric antipilferage marker
CA1238384A (fr) Garniture antivol, son detecteur, et fabrication du systeme
EP0451812B1 (fr) Marqueur magnétique dans un système de surveillance d'articles et procédé pour produire dudit marqueur
US5580664A (en) Dual status thin-film eas marker having multiple magnetic layers
US4857891A (en) Random-filament, multi-directionally responsive marker for use in electronic article surveillance systems
JP3372117B2 (ja) 磁気マーカー及びその製造方法
US4829288A (en) Economic, multi-directionally responsive marker for use in electronic article surveillance systems
EP0737948B1 (fr) Etiquette de marquage réentrant à fils multiples avec commutation simultanée
EP0604293B1 (fr) Etiquette à couche mince à double état pour la surveillance électronique d'articles
US4825197A (en) Dual status magnetic marker having magnetically biasable flux collectors for us in electronic article surveillance systems
US5166501A (en) Financial transaction cards having tagging element capable of deactivation by application of personalizing data
EP0700558A1 (fr) Marqueur pour la surveillance d'articles, a etat persistant
JP4309065B2 (ja) 光学的記録媒体用の電子物品監視マーカー
US4884063A (en) Dual status magnetic marker having magnetically biasable flux collectors for use in electronic article surveillance systems
GB2080075A (en) Improved Magnetic Marker

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB IT SE

17P Request for examination filed

Effective date: 19941128

17Q First examination report despatched

Effective date: 19970327

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB IT SE

REF Corresponds to:

Ref document number: 69328819

Country of ref document: DE

Date of ref document: 20000713

ITF It: translation for a ep patent filed
ET Fr: translation filed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2148211

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20011204

Year of fee payment: 9

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20051220

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20071226

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20071227

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20071227

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20071217

Year of fee payment: 15

EUG Se: european patent has lapsed
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20081220

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20090831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081220

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20081222

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081231

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081222

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081221