JP5935429B2 - Identification method of anti-counterfeit media - Google Patents

Description

The present invention relates to a method of identifying anti-counterfeit medium suitable anti-counterfeit member applied is attached to the medium requiring anti-counterfeiting measures.

  In recent years, copying machines using electrophotographic technology have become widespread, and anyone can easily copy characters and images printed on paper using this. In particular, with recent color digital copying machines, it has become possible to easily create even a copy that is extremely difficult to distinguish between a manuscript and a copy.

  For this reason, a technique has been proposed in which a special portion that cannot be reproduced by a color copying machine is provided on a medium such as securities that requires anti-counterfeiting. Among these, a technique of providing an OVD (Optical Variable Device) foil (see Patent Documents 1 and 2) such as a hologram foil on the surface of securities or the like has already been put into practical use. According to this, since the light on the silver surface of the hologram is specularly reflected, it cannot be reproduced by combining Y (yellow), M (magenta), and C (cyan) color toners. When a copy is reproduced in black or ceramics with different refractive indexes are laminated on a plurality of layers having an appropriate film thickness, a special optical thin film whose color changes depending on the viewing angle is formed (see Patent Document 1). Since this property cannot be obtained with a copy, the authenticity can be easily determined. Furthermore, the thin film formed by this method is crushed into a scaly shape, and the fragments are mixed into an ink binder. A method for printing is also proposed.

  However, because of the development of embossing technology for holograms, the formation of reflective layers using relief-type diffracted light has become more difficult than before, and multilayer films have begun to be sold as general packaging films. Therefore, the forgery prevention effect has been reduced.

  For this reason, in recent holograms, a method has been proposed in which a region for generating diffracted light is partially provided and, for example, a forgery prevention effect is improved by expressing micro characters or micro patterns by the hologram (Patent Literature). 2).

  A hologram that partially includes such a region that generates diffracted light is generally manufactured by a method in which a reflective layer such as a patterned metal is provided on a relief type diffractive structure. The following four methods are generally used for patterning a reflective layer of metal or the like (see Patent Document 3).

1) An etching process in which a washing ink is printed in a positive pattern on a substrate and a pattern is formed by corroding a portion not printed with a mask agent with a corrosive agent.
2) An etching process in which a mask agent is printed as a positive pattern on the metal reflective layer, and a pattern is formed by corroding a portion not printed with the mask agent with a corrosive agent.
3) Laser processing for forming a pattern by applying a strong laser to a portion of the metal reflective layer to be removed and selectively destroying the reflective layer of metal or the like.
4) By printing a photoresist agent on the entire surface of the metal reflective layer, photoresist with a positive pattern, dissolving and removing the photoresist agent in the negative pattern portion, and corroding the metal reflective layer simultaneously or in a separate process Photoresist processing to form a pattern.
However, as described above, since there are various methods for producing a reflective layer made of a patterned metal or the like, it cannot be said that the effect of preventing forgery by pattern formation has been improved.

  On the other hand, by forming microscopic holes in a substrate such as paper and forming the microholes in a pattern as a set of fixed intervals, it is difficult to see the holes visually, but light that can be seen through the micropores when light is held over Diffuses and the formed pattern can be visually observed. In order to open a minute hole in a substrate, since a needle or a laser is used, the shape of the hole is usually circular or elliptical, but by masking the laser beam to be irradiated, a hole of an arbitrary shape is opened, There is a method of judging authenticity by looking at it with a loupe (see Patent Document 4).

  However, in this method, it is necessary to use a loupe for true / false judgment, and it takes time and technology to judge the shape by looking at the micro holes with a special shape that cannot be seen with the loupe. Is complicated.

JP 2004-505158 A JP-A-2005-99090 JP 2003-255115 A JP 2002-254868 A

The present invention aims at providing a method for identifying the medium for preventing forgery of the authenticity determination of the medium according to the counterfeit preventing member can be relatively simple to implement.

The invention according to claim 1 to achieve the above object is a method for identifying an anti-counterfeit medium provided with a forgery prevention member on a substrate, wherein the anti-counterfeit member is provided with at least a metal reflection layer. A transfer foil or a seal-shaped member, and the metal reflective layer has a portion in which the metal is removed in the form of minute characters or symbols having a width and height of 0.25 mm or less at equal intervals; wherein there is formed a character or symbol by the sequence of collection of micro-characters or symbols in said anti-counterfeit medium, the formed in the fine lower case or symbols by holding the light in the portion where the forgery preventing member is attached characters or symbols appearing by aggregates, and by superimposing the convex lens array composed of the same pitch as the arrangement interval of the minute characters or symbols, the fine lower, or No. characterized in that the appearance is enlarged.

According to the present invention can provide a method for identifying the medium for preventing forgery it can be relatively easily carried out authenticity determination of the medium according to the counterfeit preventing member.

The anti- counterfeiting member affixed on the base material in the anti-counterfeit medium is a diffraction grating-like patch or stripe with a metallic luster, but when viewed through the light, the light is emitted from the minute holes from which the metallic luster has been removed. Leaked and micro holes that are not normally visible are recognized as a pattern of characters or symbols, and in this state, if microlens array films arranged at the same pitch as the micro hole array are overlaid, the characters formed with the micro holes Or patterns such as symbols emerge. This makes it possible to determine authenticity using a simple verification method, and by using a simpler verifier, further authenticity determination is possible, and it is attached to securities and certificates as a transfer foil or seal, ensuring security. Can be improved.

The top view which expands and shows a part of an example of the forgery prevention member used in embodiment of this invention. The top view which shows an example which stuck the forgery prevention member used in the said embodiment on securities. Schematic for demonstrating the authenticity determination method of the forgery prevention medium shown in FIG. The conceptual diagram which showed the structure of the verification film used for the authenticity determination of the forgery prevention member which concerns on the said embodiment. Schematic for demonstrating the authenticity determination method of the forgery prevention medium shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

One form of the forgery prevention member used in the present invention is a transfer foil having a metal reflection layer or a seal-shaped forgery prevention member. The forgery prevention member 1 shown in FIG. It is composed of Further, depending on the form of the member, a diffraction grating layer, a peeling protective layer, an adhesive layer, or an adhesive layer can be provided on the upper surface or the lower surface of the metal vapor deposition section 12 (not shown). The window opening 13 provided in the forgery prevention member 1 forms characters or symbols as shown in the enlarged view of FIG. 1, and the window openings 13 are aligned at regular intervals. Furthermore, the aligned window openings 13 further form letters or symbols in the forgery prevention member 1.

  In addition to the method described in the prior art, the method for forming the window opening portion 13 can improve the water repellency by providing a fine raised structure portion as described in JP 2009-63703 A, for example. There is also a method in which a portion not formed is formed and the metal vapor deposition portion 12 is etched.

  The size of one character or symbol of the window opening portion 13 is 0.25 mm or less in both width and height, and if it is larger than this, the window opening portion 13 can be visually recognized. The effect cannot be expected. On the other hand, if it is too small, the characters hidden in the anti-counterfeiting member 1 will not appear unless strong light is irradiated, or the metal deposition part 12 cannot be shielded due to the strong light, and the anti-counterfeiting member There is a possibility that characters hidden in 1 cannot be visually recognized. Therefore, it is preferable that one size of the window opening 13 is in the range of 0.02 to 0.25 mm in both width and height.

Another form of the anti-counterfeit member used in the present invention is the anti-counterfeit member 1 shown in FIG. By providing the diffraction grating, a function of visually judging whether the image is true or false is added, and the effect of preventing forgery is further enhanced. As this diffraction grating, a relief-type embossed hologram is generally used. However, any other method may be used as long as it has a visual forgery prevention effect.

One form of an anti-counterfeit medium used in the present invention is an anti-counterfeit medium 2 shown in FIG. 2 in which a printing unit 21 is provided on a base material and an anti-counterfeit member 1 is attached. The base material is not specified as long as it is a single or combination of paper, plastic sheet, glass, wood, rubber, etc., but light is visible on the front side when light is irradiated from the back surface of the base material when judging authenticity. It needs to be a thing.

The embodiment of the present invention relates to the authenticity determination method for the forgery prevention medium 2 shown in FIGS. When the anti-counterfeit medium 2 is viewed with normal visual observation, the anti-counterfeit portion 1 is a foil or a seal formed of a diffraction grating such as a metallic luster or a hologram, and the authenticity determination by visual inspection is possible. However, as explained in the prior art, since the manufacturing of the diffraction grating has become difficult, as a further authenticity determination means, the anti-counterfeit medium 2 can determine the authenticity by the method shown in FIG. is there. In FIG. 3, the light source 31 is irradiated from the back surface of the forgery prevention medium 2. At that time, light leaks from the window opening 13 of the forgery prevention section 1 to create a contrast of light and dark with the metal vapor deposition section 12, and a character pattern formed by the window opening 13 appears (light is applied from the back side). (13a). When there is no light source 31 for irradiating the back surface, indoor lighting or sunlight can be substituted.

  FIG. 4 is a schematic view of the verification film 4 used when further determination of the authenticity of the anti-counterfeit medium 2 is performed. The surface of the verification film 4 is formed by a convex lens array 41 spread at a certain interval. Has been. By causing the pitch of the convex lens array 41 and the pitch of the window opening 13 to coincide with each other, a phenomenon as introduced in Japanese Patent Nos. 2761861 and 4907049 occurs, as shown in FIG. The shape of the window opening 13 is enlarged and can be seen with the eyes (the appearance 13b in a state where the verification film 4 is overlaid and light is applied from the back surface). Although the shape of the window opening 13 can be enlarged with a magnifying glass, it takes time to focus, etc., so it cannot be verified in large quantities at once. False determination is possible.

A polyurethane-based resin was applied to a 12 μm thick transparent PET substrate with a dry film thickness of 2 μm to produce a hologram forming layer. Subsequently, a diffraction grating was formed on the surface of the relief structure forming layer by a roll embossing method to obtain a hologram embossing. Next, 80 nm of pure aluminum was deposited by vacuum deposition. The aluminum deposited layer was blown with a YAG laser at a character height of 75 μm and a line width of 10 μm to form a “¥” mark. This mark is formed at a pitch of 150 μm in the vertical direction and the horizontal direction, and the letter “T” is formed as a whole, and an acrylic adhesive layer is applied thereon with a dry film thickness of 20 μm, cut into a predetermined size, A forgery prevention medium was obtained by pasting on a printed material having a pattern printed on high-quality paper having a thickness of 100 g / m ² .

  The anti-counterfeit medium of Example 1 is visually provided with a hologram patch, so that authenticity can be determined. However, when light is irradiated from the back of the anti-counterfeit medium, a window opening on the hologram that was not visually observed Light leaked from the part, and the letter “T” was visible. Further, when a verification film with an embossed convex lens array with a pitch of 150 μm was stacked in a state where light was applied from the back surface, the character “¥” was enlarged and visually recognized.

The present invention provides a medium for preventing forgery, in addition to the authenticity determination by visual, provides a method of identifying counterfeit prevention medium capable multiple validation methods.

  In addition to the visual verification, a further anti-counterfeiting effect can be expected from the fact that a simple method can be used for further authenticity determination.

  DESCRIPTION OF SYMBOLS 1 ... Anti-counterfeit member, 2 ... Anti-counterfeit medium, 4 ... Verification film, 12 ... Metal vapor deposition part, 13 ... Window opening part, 13a ... How the light is applied from the back surface, 13b ... Overlay the verification film , 21 ... printing part, 31 ... light source, 41 ... convex lens array.

Claims (1)

A method for identifying an anti-counterfeit medium provided with an anti-counterfeit member on a substrate,
The anti-counterfeiting member is a transfer foil or a seal-shaped member provided with at least a metal reflective layer, and the metal reflective layer has a width and height of 0.25 mm or less, and the metal is removed in the form of small letters or symbols. Are arranged at equal intervals, and further, a character or symbol is formed by an array of a collection of the minute characters or symbols,
In the anti-counterfeit medium, the characters or symbols by aggregate formed by fine lowercase or symbols appearing by holding the light in the portion where the forgery preventing member is attached, and the arrangement interval of the minute characters or symbols An anti-counterfeit medium identification method, wherein the minute characters or symbols appear in an enlarged manner by overlapping convex lens arrays configured at the same pitch.

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