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
  • G08B13/2414—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 inductive tags
  • G08B13/242—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
  • G08B13/2434—Tag housing and attachment details

Definitions

• the present invention relates to methods for neutralizing an anti-theft device of the kind operating by influence on a detector placed for example at the exit of a store.
• the present invention also relates to an anti-theft device suitable for implementing the above-mentioned methods.
• the invention also relates to an article, in particular clothing or the like, carrying such an anti-theft device operating by influence.
• an anti-theft device to each article. If a person seeks to fraudulently take away the item of clothing, the anti-theft device influences a detector placed in a warning barrier arranged at the exit of the store. To avoid triggering the alarm when an honest customer leaves the store, several methods exist depending on the type of means of influence that is housed in the device. If the anti-theft device is made in the form of a badge, the store staff must remove the device before the customer goes through the warning barrier. The merchant must therefore have the stock of badges, apply the badges before the sale, and deposit the badges with each sale. This is very restrictive.
• DE-A-32 12 039 discloses an anti-theft influence device in the form of a thin label with an oscillating coil circuit, which can be fitted to numerous articles, books, clothes, etc. To neutralize the label, the document proposes to cut or punch or puncture part of the label to destroy the electrical conductors.
• CH-A-656 472 describes an anti-theft label comprising a pre-cut part. To neutralize the label, the precut part is removed, which carries part of the circuit forming the coil. This label was not satisfactory in practice because malicious customers can easily understand, by the presence of the precut dots, the method intended to neutralize the label and can therefore themselves implement this method before crossing the barrier warning.
• EP-A-0 209 916 discloses a method for neutralizing these same thin oscillating circuits.
• the coil is placed in a sufficiently strong magnetic field to allow the induced current flowing in the coil to trip an intended neutralization device.
• EP-A-0 123 557 discloses an anti-theft influence means in the form of a thin and thin strip of ferromagnetic material.
• the neutralization of this ferromagnetic marker is made possible by adding to the strip, small magnetizable sections. As soon as a magnetic field is applied, the small sections are magnetized and permanently polarize the ferromagnetic strip. The marker becomes undetectable to the monitoring device.
• This neutralization also has the disadvantage of being reversible because the magnetization of the small sections in question can decrease in intensity over time and thus allow the activity of the ferromagnetic band to reappear.
• FR-B-2 623 003 also discloses a magnetic marker which can be deactivated by subjecting it to an amplitude and / or frequency field much higher than the amplitude or the frequency of the detection field. This deactivation has the effect of dislocating the boundaries of the magnetic domains of the marker which then has a hysteretic characteristic different from that in the active state.
• This neutralization mode can however have a reversible character and, in any case, only relates to magnetic markers having a hysteretic characteristic pre-established during the development of the marker.
• the object of the invention is to remedy these drawbacks of lack of effectiveness of known magnetic and mechanical neutralization.
• the method for neutralizing an influence means included in an anti-theft device is characterized in that the mechanical action is transmitted from the outside to the inside of the device with maintenance of the integrity of the device when the means of influence is deactivated.
• the invention avoids the need to resort to the ablation of part of the label. Unauthorized persons cannot therefore easily know the steps to be taken to deactivate the anti-theft device.
• a substance in the form of colloidal gel is used as the means of neutralization which, in a waiting position, is close to the anti-theft influence means.
• a mechanical action exerted on the anti-theft device causes the gel to pass from its standby position to a neutralization position where the gel is dispersed on the anti-theft influence means and thus alters at least one physical property of the anti-theft device.
• the method for neutralizing a means of influence included in an anti-theft device is characterized in that first activates a first neutralization means and in that one leaves a second neutralization means that can be activated by mechanical action exerted exterior to interior of the device while maintaining the integrity of the device.
• first activates a first neutralization means and in that one leaves a second neutralization means that can be activated by mechanical action exerted exterior to interior of the device while maintaining the integrity of the device.
• the means of neutralization by mechanical action remains unknown to the purchaser of the article, or even to the seller. Both have the opportunity to know only the first means of neutralization.
• the mechanical aggressions will tend to reactivate the first means of neutralization but will at the same time cause neutralization by the second means of neutralization, which will thus take over from the first.
• the anti-theft device comprising a label in which is integrated an influence means capable of influencing by proximity a detector of the kind placed at the exit of a store, this device further comprising means for neutralization of the means of influence by mechanical action on the label, is characterized in that the neutralization means are arranged in the label and are sensitive to the mechanical action transmitted from the outside to the inside of the label with maintenance of the integrity of the anti-theft device during the neutralization process and at the end of it.
• a protective layer preferably a gel of silicone material.
• the article is characterized in that it comprises an anti-theft influence device according to at least one of the third and fourth aspects.
• the article is in particular a garment or the like, in particular an article which it is usual to carry on oneself and for which it is consequently very annoying that the anti-theft device is reactivated after a certain time of use.
• FIG. 1 is a top view of an anti-theft influence tag comprising an oscillating coil circuit and means for its selective neutralization;
• FIG. 2 is a view similar to Figure 1 but relating to a variant of the neutralization means
• FIG. 3 is a view similar to Figure 1 but where the means of influence is of the ferromagnetic strip type
• - Figure 4 is a sectional view of an anti-theft label according to Figure 1 but reinforced by a protective layer and simplified as regards the neutralization means.
• the anti-theft device is in the form of a flexible label having a thickness similar to that of a sheet of paper.
• This label contains a means of influence 2, 4, 22, housed for example between a sole 41 of the label and a protective sheet 18 of
• the means of influence can be of the oscillating circuit type comprising a flat coil 2, with conductive aluminum turns 3 playing the role of circuit resonating at a given frequency (of 8.2 megaHertz for a dimension of 4 x 4 cm).
• a flat capacitor 4 connects the two ends of the coil.
• the coil and the capacitor are placed on one side of a support plastic sheet 6 of slightly larger size, the other side of which is fixed to the sole 41.
• the sole 41 On its face opposite to the sheet 6, the sole 41 is self-adhesive. It is thus possible to arrange the anti-theft device by gluing on all the packaging of objects or objects such as clothing 7 to be protected against theft.
• the anti-theft label 1, 10, 30 can be neutralized by subjecting the label to a mechanical pressure action P causing the spreading of a substance 8 on the coil 2 so as to create conductive bridges d electricity between the turns 3 of the coil 2. A short circuit of this coil 2 is thus produced. The circuit will therefore no longer oscillate under the effect of the magnetic detection field emitted by the detection means placed at the outlet of the stores.
• the substance 8 which will be at the origin of this short circuit is composed of electrically conductive material.
• substance 8 is a colloidal gel having the appearance of glue or gelatin. This gel used has determined rheological properties intermediates between the liquid state and the solid state. The use of a gel allows both the diffusion as soon as the label is pressed and makes it possible to avoid a flow of liquid if a piercing of the label occurs.
• the gel contains preferably water or a hydrogel in which water is the dispersing medium, made from polymers or mixtures of natural or synthetic polymers, hydrophilic and swelling in the presence of water, of the agarose, acrylamide, polyacrylamide type bisacrylamide.
• the colloidal gel 8 may contain ionic species which further improve the electrical conductivity.
• the gel When manufacturing the label 1, 10, the gel is placed in the standby position near the influence means 2, 3, 4 while being separated from the latter.
• the colloidal substance 8 will be transferred from its standby position to a position of neutralization of the means of influence by sliding and spreading under the action of a pressure force P.
• the substance 8 In the standby position, the substance 8 is for example placed in a mass between the outer protective sheet 18 and an intermediate sheet 19 separating the gel 8 from the circuit 2, 3, 4.
• the sheets 18, 19 defining between them a pocket next to the circuit 2, 3, 4.
• the colloidal gel 8 is thus kept in constant humidity without possible drying.
• One or more orifices 21 are drilled at a distance from the pocket, in the intermediate sheet 19 pressed directly on the turns 3 so as to allow the diffusion of the gel 8.
• circuit 2, 3, 4 For the reserve of substance 8 in the waiting position, it is also possible to create next to circuit 2, 3, 4, a pocket 17 or several pockets 17a, 17b, 17c sealed on four edges 11, 12, 13 and 14 with reference to FIG. 2.
• the edge 14 located along circuit 2, 3 , 4 is sealed by a weaker resistance line so that the substance 8 by this edge 14 directly on the flat coil 2.
• plastic pipes 16 of very small section are provided from the reserve pockets 17a, 17b, 17c. They are directed towards the center of the anti-theft influence label 10 and open towards the middle of the label 10 or else towards the region of the turns 3 located away from the reserve pockets 17a, 17b, 17c.
• the 0 gel 8 will thus diffuse over the entire surface of the flat coil.
• the means of influence is of the ferromagnetic band type. It then comprises a thin strip 22 of amorphous ferromagnetic material placed on one side of a support sheet 31 of plastic material, the other side of which is fixed to the sole 41.
• the ferromagnetic strip 22 is composed of 5 soft materials influencing the magnetic field sensor of the store barrier.
• the substance used to neutralize the ferromagnetic band is chosen to ensure, once released, a permanent polarization of the band, which will make it insensitive to the 0 detector field.
• a small amount of hard residual powder is mixed with the colloidal gel 8 ′. After diffusion of the gel 8 'above the strip 22, the latter will be insensitive to any external physical stress.
• the material or mixture of hard residual material has coercivity such that re-magnification is not possible with the magnetic fields usually generated.
• Powdered materials of the ferrite Fe 2 0 3 or Samarium-Cobalt SmCo 5 or Sm 2 Co 7 type are suitable.
• Another means of neutralization consists in providing, in the composition of the colloidal gel 8 ′, a compound degrading the ferromagnetic band 22. Even with a low concentration, the compound will attack the band 22, which will cause a seed to recrystallize the material. amorphous ferromagnetic.
• the compound will also act by degrading the surface of the ferromagnetic strip.
• properties of the strip depend on an optimal ratio between the length and the square root of the area of the cross section of the strip, an alteration by pickling will lead to the neutralization of the strip.
• a strong acid such as nitric acid or hydrofluoric acid is suitable.
• a mechanical action makes it possible to diffuse it over the strip 22 in the same way and by the same methods as those described above.
• neutralization can be achieved by causing a mechanical action exerted on the outside of the label and transmitted inside thereof, spreading of a substance with particular properties, so that it associates closely by means of influence. More specifically, the mechanical pressure action P, causing the spreading of the substance on the means of influence and the annihilation of its effects, can be exerted voluntarily by means of a finger 23. But in particular in the case of articles of clothing or the like, pressure may be produced unconsciously by the consumer after purchase during handling of the object in question or when washing or ironing. Any reactivation will therefore not be possible, since neutralization by mechanical action will be final.
• the new neutralization means are combined with the known neutralization means, for example having the effect of applying to the anti-theft device operating by radio frequency a field whose high intensity neutralizes the means of influence by damaging the oscillating circuit. or a specific part of it, intentionally weakened during manufacture.
• the cashier deactivates the device by the traditional means which have just been recalled, therefore without application of the mechanical action such as P.
• this traditional deactivation has the disadvantage of being reversible , especially if the device undergoes vigorous handling during washing, ironing or during use.
• the anti-theft device can be placed after said treatments, but this increases the manufacturing costs. This is why it is proposed according to the invention to place on the article, before the treatments, a reinforced anti-theft device so that it retains a lot of flexibility but can less easily be folded at a sharp angle than a traditional anti-theft label. .
• a reinforced anti-theft device so that it retains a lot of flexibility but can less easily be folded at a sharp angle than a traditional anti-theft label.
• at least one sheet of the label a material of the elastomer or similar type which may have a certain thickness without being rigid.
• a heat-resistant protective layer 42 preferably a lacquer of silicone material.
• Such a lacquer initially in a more or less liquid form, exhibits characteristics of elasticity, flexibility and thinness when dry, withstands temperatures of the order of 200 ° C., constitutes an insulating layer protecting the rest of the heat label, prevents the label from undergoing violent local deformations, absorbs shock and promotes sealing. It is advantageous to place the lacquer 42 in particular on the side to be subjected to the attack such as ironing. So if the device is attached to the back of a fabric which will be ironed from the right side, it may be necessary to protect the sole 41 as shown. The seal prevents penetration of hot liquid or steam into the label.
• composition of the gel may be variable, the quantities of the compounds present depending on the size of the anti-theft influence label to be neutralized.

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• 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)

Applications Claiming Priority (3)

Publications (1)

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ID=9469207

Family Applications (1)

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• 1994
  • 1994-11-28 FR FR9414226A patent/FR2727550A1/fr active Granted
• 1995
  • 1995-11-28 CA CA002206791A patent/CA2206791A1/fr not_active Abandoned
  • 1995-11-28 WO PCT/FR1995/001565 patent/WO1996017332A1/fr not_active Application Discontinuation
  • 1995-11-28 AU AU42647/96A patent/AU4264796A/en not_active Abandoned
  • 1995-11-28 US US08/849,026 patent/US5926094A/en not_active Expired - Fee Related
  • 1995-11-28 EP EP95941149A patent/EP0795166A1/fr not_active Ceased

Non-Patent Citations (1)

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