JP5703767B2 - Anti-counterfeiting medium and tampering judgment method - Google Patents

Description

  The present invention relates to an anti-counterfeit medium that prevents counterfeiting of gift certificates, tickets, and the like, and a method for determining the presence or absence of tampering.

  More specifically, the present invention has a function of visualizing a latent image by overlaying a visualization filter (polarizer) on a latent image layer having a latent image before performing the predetermined operation. The latter relates to a medium having a function of making a latent image visible and losing information using radio waves by performing a predetermined operation.

  The present invention also relates to a determination method capable of determining that a medium has not been tampered with by confirming a function for acquiring information and a function for visualizing a latent image before and after performing the predetermined operation. is there.

  Further, the present invention relates to the determination method, which makes it extremely difficult to return the state after performing a predetermined operation to the state before performing the predetermined operation, thereby preventing forgery of the medium. The present invention relates to a highly forgery prevention technical medium.

  As a technique for acquiring information by utilizing radio waves, there is a technique for detecting the presence or absence of resonance, as proposed in Patent Document 1, for example, and is used for a shoplifting prevention tag or the like. In this method, the presence or absence of a tag can be detected only by the person who passes the gate, that is, the owner can be detected. Further, it is possible to effectively disable the passage detection function by shifting the resonance frequency by a predetermined operation.

  In addition, as proposed in Patent Document 2, most of the IC chips having an ID having an ID are those having a unique ID, and the IC chip is contactlessly fed by radio waves. ID information can be acquired from the IC chip by wireless communication after driving. In addition to the ID information, there are many devices having various functions and large-capacity memories, and they are widely used for transportation schedules and prepaid cards.

  For example, if the above technology is incorporated into a ticket, it can be used for various authentications and services such as entrance / exit management and various guidance, and even if the ticket is forged in the same way, it uses radio waves. It is also possible to determine forgery by confirming and authenticating the function of the received tag.

  Since both can communicate in a non-contact manner, there is a merit that it can be automatically recognized without a human hand, and it is very convenient to be used in various fields.

JP 2005-50077 A Japanese Patent No. 4518585

However, while the technology for acquiring information by non-contact communication using radio waves is very convenient, a malicious person reads the ID information or checks the resonance frequency without the intention of the owner. In most cases, skimming is possible, and the owner is completely unaware of the fact that he has received the act.

  Therefore, if you have a certain level of technology, based on the information obtained by skimming, you can create a pseudo tag that emits a radio wave with a specific ID or a device that reacts to a specific resonance frequency. It is possible to bypass authentication by radio wave communication.

  Until the authenticity judgment is made for the above problem, communication by radio wave etc. is made impossible at all, and after confirming that communication is impossible, it is possible to communicate for the first time by a predetermined operation. By performing a double check of confirmation, it can be proved that skimming has not been performed by radio waves until the authenticity determination is performed, and thus anti-counterfeiting can be expected.

  After performing the predetermined operation, it is possible to start providing various services by non-contact communication using radio waves that were impossible until the predetermined operation.

  In addition, if there is a function that clearly changes the state visually before and after performing a predetermined operation, it is possible to further improve security, and return to the state before performing the predetermined operation. However, it becomes extremely difficult.

  Therefore, according to the present invention, communication is impossible until a predetermined operation is performed, communication is possible after the operation is performed, and a pattern that is visible until the operation is performed is visible after the operation. It is an object to provide an anti-counterfeit medium that becomes impossible and a tampering determination method.

The invention according to claim 1 is a radio wave communication layer that can acquire various information in a non-contact manner by utilizing resonance of radio waves of a specific frequency;
A low melting point metal thin film layer having a metallic luster provided facing the radio wave communication layer;
Further, a phase difference layer including a latent image provided on the surface in contact with the low melting point metal thin film layer on the side opposite to the surface in contact with the radio wave communication layer is partially provided, or the orientation direction is partially different. And a latent image layer provided with a retardation layer .

Invention of claim 2, and the radio wave communication layer obtainable in a non-contact various information by utilizing the resonance of the radio wave of a specific frequency, and the printing layer, and the low melting point metal thin film layer having a metallic luster, position An anti-counterfeit medium characterized in that a phase difference layer is partially provided, or a latent image layer provided with a phase difference layer so that the orientation direction is partially different is sequentially laminated.

  The invention according to claim 3 is the anti-counterfeit medium according to claim 1 or 2, wherein the low melting point metal thin film layer is zinc or lead.

  The invention according to claim 4 is the forgery prevention medium according to any one of claims 1 to 3, wherein the low-melting-point metal thin film layer is partially removed beforehand.

  The invention according to claim 5 is the forgery prevention medium according to any one of claims 1 to 4, wherein the low-melting-point metal thin film layer transmits light and radio waves by applying heat.

  A sixth aspect of the present invention is the forgery prevention medium according to any one of the first to fifth aspects, wherein various kinds of information can be obtained by applying heat to the low melting point metal thin film layer.

  The invention according to claim 7 is the forgery prevention medium according to claim 1 or 2, wherein the latent image layer is partially provided with a retardation layer.

  The invention according to claim 8 is characterized in that the latent image layer is composed of a retardation layer in which the orientation directions of the specific pattern portion and portions other than the specific pattern portion are different. Is a forgery prevention medium.

  The invention according to claim 9 is the forgery prevention medium according to claim 7 or 8, wherein the latent image of the latent image layer can be visually recognized by using a polarizer.

According to a tenth aspect of the present invention, in the falsification prevention medium falsification determination method according to any one of the first to ninth aspects, the latent image is visually recognized using a polarizer before the latent image layer is heated. This is a falsification presence / absence determination method characterized in that the presence / absence of falsification is determined using the fact that visual recognition is impossible after heat is applied.

  According to the anti-counterfeit medium and the falsification presence / absence determination method of the present invention, it is possible to prove that a medium requiring high security has not been falsified before the authenticity determination, and the operation based on the authenticity determination is performed. Since it is extremely difficult to return to the previous state from the back, it is possible to prevent forgery.

  In addition, it is possible to acquire various information for the first time by applying heat, and the specific pattern that is visible by overlapping polarizers is not visible to the naked eye, so only a person who knows the visual recognition method can confirm the specific pattern. Therefore, the forgery prevention effect is maintained even before the operation based on the authenticity determination.

The figure which shows the typical example of the layer structure of the forgery prevention medium of this invention in a cross section. FIG. 2 is a schematic diagram when the visualization filters are overlapped when viewed from above. The figure which shows the cross section which added the printing layer to the structure of FIG. The figure which shows the layer structure which added the printing layer 31 to the layer structure of FIG. 1, and was provided. The top view which showed that the low melting-point metal thin film layer of FIG. 1 was partially missing beforehand.

  FIG. 1 is a diagram showing a cross-section of a representative example of the layer structure of the anti-counterfeit medium of the present invention, and a radio wave communication layer 11 that can acquire various information in a non-contact manner by utilizing resonance of radio waves of a specific frequency, A low melting point metal thin film layer 12 provided facing the radio wave communication layer 11 and a latent image including a latent image provided on a surface that is in contact with the low melting point metal thin film layer 12 on the side opposite to the surface in contact with the radio wave communication layer 11. And an image layer 13.

  The radio wave communication layer 11 corresponds to, for example, an industrial or commercially available IC tag inlet or a shoplifting prevention tag sold for stores. Conductive power that can resonate with radio waves of a specific frequency or consume power, or can supply power for wireless communication by supplying power to an IC chip from a rectina circuit used in the input part of an IC tag. A metal antenna is provided.

  The low-melting-point metal thin film layer 12 is obtained by thin-film coating a metal that melts at a relatively low temperature with a melting point of several hundred degrees using a method such as vacuum deposition.

  The latent image layer 13 is a layer in which a phase difference layer is partially provided or a phase difference layer is provided so that the alignment direction is partially different.

The radio wave communication layer 11 is usually optimized so that information can be acquired by radio waves from a specific wireless device in a state where it is attached to or incorporated in a support such as paper or film, an article, or the like. Therefore, if a conductive metal such as the low-melting-point metal thin film layer 12 is in close contact, the resonance frequency is greatly shifted, and the antenna is integrated with the low-melting-point metal thin film layer 12 in radio waves. It becomes virtually unusable.

  However, the low-melting-point metal thin film layer 12 formed by vacuum deposition or the like melts relatively easily by applying heat, and cannot maintain the thin film shape. Specifically, when the metal melts, due to the wettability of the metal itself, the metals attract each other on the surface, and an infinite number of dot patterns are distributed on the surface. In such a state, light and radio waves are transmitted. For this reason, the radio wave communication layer 11 that is in close contact with the radio communication layer 11 changes to a state in which information can be acquired by radio waves emitted from a specific wireless device.

  As a method for removing the metal thin film, a wet etching method in which the metal thin film is immersed and dissolved in an acidic liquid can be considered, but a method of applying heat to the low melting point metal thin film layer 12 is a very easy and simple method.

  On the other hand, the latent image layer 13 is partially provided with a retardation layer or a retardation layer so that the alignment direction is partially different. FIG. 2 is a schematic view when the polarizer 21 is overlapped when the invention of FIG. 1 is viewed from above. When the phase difference of the portion 22 where the phase difference layer is partially provided is λ / 4, When the polarizers 21 are stacked, the light polarized by the polarizers 21 becomes circularly polarized light when entering the retardation layer. Subsequently, before the heat is further applied to the lower layer, the low-melting-point metal thin film layer 12 having a thin film shape has a metallic luster, and thus reflects light that has been circularly polarized by the retardation layer. At this time, the phase of the circularly polarized light is reversed and enters the phase difference layer again, so that the polarizer 21 is finally linearly polarized light twisted 90 degrees. In particular, the light that has passed through the portion 22 provided with the retardation layer cannot pass through the polarizer 21 and therefore appears black. Portions other than the portion 22 where the retardation layer is partially provided appear white when only reflected by the low melting point metal thin film layer 12. Thus, in this case, the latent image can be visualized by overlapping the polarizer 21 on the latent image layer 13.

  However, when heat is applied to the low melting point metal thin film layer 12 as described above, light is transmitted. As a result, when the latent image layer 13 has the above-described configuration in which the retardation layer is provided only in the portion 22 where the retardation layer is provided partially, Since the light that has been circularly polarized by the phase difference layer is not reflected by the low-melting point metal thin film layer 12, it is not visible as a latent image. Therefore, the latent image layer 13 loses the latent image.

  By having a function of confirming the latent image of the latent image layer 13, a malicious person obtains the medium and applies the low melting point metal thin film layer 12 by a method such as applying heat or immersing in an acidic liquid. Even after the removal and analysis of the radio wave communication layer 11, the low melting point metal thin film layer 12 b is provided again as shown in FIG. Since it is provided in the upper layer, the latent image on the latent image layer 13 becomes invisible even before heat is applied, so that it is possible to easily determine that the hand has been applied. In FIG. 3, 11 is a radio wave communication layer, 12a is a low melting point metal thin film layer after heat is applied, and 13 is a latent image layer.

  4 shows a layer structure in which a printing layer 31 is provided between the radio wave communication layer 11 and the low melting point metal thin film layer 12 in FIG. Before this heat is applied, the layer is sandwiched between the radio wave communication layer 11 and the low melting point metal thin film layer 12 and thus cannot be visually recognized. However, after the heat is applied, the low melting point metal thin film layer 12 transmits light. It becomes visible because it comes to do. As a result, it is possible to print an explanatory note that introduces the function of the radio wave communication layer 11 that can be used after heat is applied, or to give a beautiful decoration by printing.

  FIG. 5 is a view showing that a part of the low melting point metal thin film layer 12 is previously omitted. Even if the entire surface of the radio wave communication layer 11 is not completely covered, even if the low melting point metal thin film layer 12 having a certain area covers only a part of the antenna of the radio wave communication layer 11, the radio communication layer 11 greatly affects communication. Communication becomes impossible. Therefore, the low-melting-point metal thin film layer 12 can be given a design by the portion 41 from which the low-melting-point metal thin film layer has been partially removed in advance. However, even after a part of the low melting point metal thin film layer 12 is removed, the radio wave communication layer 11 cannot be used, and the portion 41 where the low melting point metal thin film layer has been partially removed in advance is the latent image layer 13. It is necessary not to cover the latent image portion to be developed.

  The radio wave communication layer 11 may be a resonator that resonates with the frequency of the radio wave emitted by the reading reader as long as it is only for detecting the presence or absence of resonance. In the case of an object that does not resonate with the frequency of the radio wave emitted by the reading reader by shifting the resonance frequency by a specific operation, for example, a strong output radio wave, there is a thing in which a capacitor or the like is mounted on the resonator. Such a thing may be sufficient. Also equipped with various RFID (Radio Frequency Identification) chips that have an antenna that resonates with the frequency of the radio wave emitted by the reader, that can be fed from this radio wave and activated from the rectina circuit to communicate with the reader. It may be something like an IC tag. Various frequencies such as the LF band, the HF band, the UHF band, and the millimeter wave band are used as the frequency of the radio wave emitted by the reader.

  The low melting point metal thin film layer 12 may be a low melting point metal such as tin, zinc, indium, gallium, bismuth, lead, etc. In the present invention, it is necessary to have an electromagnetic wave shielding effect. Tin is not available. In addition, since it is preferable that it is relatively inexpensive, it is preferable to use zinc or lead. In particular, zinc is easy to obtain because films deposited on PET (polyethylene terephthalate), OPP (biaxially oriented polypropylene), PPS (polyphenylene sulfide), etc. are mass-produced for industrial use, as members of film capacitors. It is preferable because it is friendly to the human body and the earth.

  The latent image layer 13 is, for example, a smectic liquid crystal or a nematic liquid crystal and having a property of a thermotropic liquid crystal in the case where the phase difference layer having a phase difference λ / 4 is partially provided as described above. A method of realizing the above by printing in a pattern using a gravure printing method or a method of bonding a retardation film cut into a pattern by using a punching die or a cutting machine can be considered. In the case of using liquid crystal, an alignment film may be used for the purpose of performing alignment more rapidly. As a material for the alignment film, a resin such as PVA (polyvinyl alcohol) or polyimide is used. It may be obtained by applying a rubbing treatment in which an appropriately dissolved resin solution is coated using a coating method such as a wire bar, gravure, or micro gravure, and then dried and rubbed with a rubbing cloth such as cotton or velvet. . In addition, it is preferable to introduce a functional group such as an acryl group at the end of the liquid crystal because the physical strength is improved when crosslinking is performed using active energy rays after the alignment of the liquid crystal is completed. Further, for such a retardation layer made of liquid crystal, a method in which a layer prepared in advance on another substrate or the like is transferred as the latent image layer 13 can be considered.

  In addition, the latent image layer 13 may have a configuration in which a retardation layer having a phase difference of λ / 4 is provided on the entire surface at an angle of 45 degrees partially formed by the alignment direction. As the method, in the rubbing process when obtaining the previous alignment film, after obtaining by rubbing in a pattern shape so that an appropriate image forming portion and its peripheral portion have an angle of 45 degrees, the liquid crystal described above, It is a technique obtained by coating the entire surface using a gravure printing method or the like.

When the retardation layer having a retardation λ / 4 as described above is used, the latent image can be visually recognized by using a normal polarizing plate that transmits linearly polarized light as the polarizer 21. By providing the retardation layer on the polarizer 21 that is a visualization filter, the retardation layer between the low-melting-point metal thin film layer 12 and the polarizer 21 may result in a total retardation λ / 4. good. For example, even if the phase difference of the latent image layer 13 is λ / 8 and the phase difference layer of λ / 8 is attached to the polarizer 21 to create a visualization filter, the latent image can be visually recognized. At this time, the angle formed by the alignment direction is 45 degrees even in the configuration in which the retardation layer having a partially different angle formed by the alignment direction is provided on the entire surface.

  Printing on the printing layer 31 can be performed using various printers.

  In order to create the portion 41 from which the low melting point metal thin film layer has been partially removed in advance, the low melting point metal thin film layer 12 may be previously removed by vapor deposition using a mask when the low melting point metal thin film layer 12 is formed. After the melting point metal thin film layer 12 is formed, the mask layer that has come out in a pattern shape may be applied by a gravure printing method or the like, and then removed by a wet etching method or the like. It may be apparently removed by applying heat, or it may be apparently removed by partially applying heat with a thermal head type printer or the like. Particularly when a thermal head type printer is used, the low melting point metal thin film layer 12 can be removed relatively easily on an individual pattern, so a portion 41 where the low melting point metal thin film layer is partially removed in advance is created on demand. In addition, if a reader for the radio wave communication layer 11 is incorporated, it can be inspected that the function of the radio wave communication layer 11 cannot be used after the low melting point metal thin film layer 12 is partially removed. .

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the spirit of the present invention.

  The present invention will be described in detail with reference to specific examples.

(Example)
A UHF band IC tag (trade name: DogBone (manufactured by UPM Raflatac)) printed with “Received” with an inkjet printer is transparently laminated, and the card-shaped object has zinc printed on the printed side. Further, the alignment film ink having the following formulation was applied to the zinc vapor deposition surface using a wire bar and then dried for 2 minutes at 100 ° C. The film thickness after drying was 3 μm. Then, using a rubbing cloth, a rubbing treatment is performed in a pattern so that an appropriate image forming portion and its peripheral portion are at an angle of 45 °. A retardation layer cured with an irradiation energy of 500 mJ was obtained using a mercury lamp, and the thickness of the retardation layer after curing was 1 μm.

(Ink for alignment film)
Polyvinyl alcohol resin: 10 parts by weight (trade name: POVAL 117 (manufactured by Kuraray Co., Ltd.))
Solvent (water / isopropyl alcohol = 95 parts / 5 parts): 100 parts by weight (rubbing cloth)
Product name: FINE PUFF YA-20-R (manufactured by Yoshikawa Chemical)
(Ink for phase difference)
Liquid crystal (trade name: Paliocolor LC242 (manufactured by BASF)): 30 parts by weight polymerization initiator (trade name: IRGACURE 184, manufactured by Ciba Geigy Japan Ltd.): 1.5 parts by weight of solvent (toluene / MEK = 1/1): 68.5 parts by weight

When a commercially available polarizing plate is superimposed on the anti-counterfeit medium thus obtained, a latent image can be visually recognized, and a reading operation is performed at an output of 250 mW of UHF band IC tag handy reader / writer, model name: AT870-RF (manufactured by Atid). After confirming that reading is not possible, if heat is applied to the entire surface with a thermal head type card printer, the zinc deposition layer appears to disappear, and the printed `` accepted '' can be seen. However, it was confirmed that the latent image became invisible and can be read by the reader / writer.

  According to the anti-counterfeit medium and the falsification determination method of the present invention, for example, by incorporating it into a VIP ticket or the like, it becomes possible to provide a special ticket that can prevent spoofing and provide various services after acceptance.

DESCRIPTION OF SYMBOLS 11 ... Radio | wireless communication layer 12 ... Low melting-point metal thin film layer 12a ... Low-melting-point metal thin film layer 12b after being heated ... Low-melting-point metal thin film layer provided in the upper layer of a latent image layer 13 ... Latent image layer 21 ... Polarizer 22 ... Partially provided with phase difference layer 31 ... Print layer 41 ... Partially removed low melting point metal thin film layer in advance Part

Claims (10)

A radio wave communication layer that can acquire various information in a non-contact manner using resonance of radio waves of a specific frequency,
A low melting point metal thin film layer having a metallic luster provided facing the radio wave communication layer;
Further, a phase difference layer including a latent image provided on the surface in contact with the low melting point metal thin film layer on the side opposite to the surface in contact with the radio wave communication layer is partially provided, or the orientation direction is partially different. And a latent image layer provided with a retardation layer . Whether a radio wave communication layer that can acquire various types of information in a non-contact manner by using resonance of radio waves of a specific frequency, a printing layer, a low-melting-point metal thin film layer with metallic luster, and a retardation layer are partially provided An anti-counterfeit medium comprising: a latent image layer provided with a retardation layer so that the orientation directions are partially different from each other .   The forgery prevention medium according to claim 1 or 2, wherein the low melting point metal thin film layer is zinc or lead.   The forgery prevention medium according to any one of claims 1 to 3, wherein the low-melting-point metal thin film layer is partially removed beforehand.   The forgery prevention medium according to any one of claims 1 to 4, wherein the low melting point metal thin film layer transmits light and radio waves by applying heat.   6. The forgery prevention medium according to claim 1, wherein various kinds of information can be acquired by applying heat to the low melting point metal thin film layer.   The anti-counterfeit medium according to claim 1, wherein the latent image layer is partially provided with a retardation layer.   The forgery prevention medium according to claim 1, wherein the latent image layer is configured by a retardation layer in which the orientation directions of the specific pattern portion and portions other than the specific pattern portion are different.   The forgery prevention medium according to claim 7 or 8, wherein the latent image of the latent image layer is visible by using a polarizer.   10. The method for determining whether or not a forgery prevention medium is falsified according to any one of claims 1 to 9, wherein a latent image can be visually recognized using a polarizer before heat is applied to the low melting point metal thin film layer. After that, a tampering presence / absence determination method characterized by performing tampering using the fact that visual recognition is impossible.

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