JPH0782285B2 - Copy protection method and copy protection medium - Google Patents

Description

The present invention relates to a copy prevention method for preventing inconvenient copying.

[Prior Art] In recent years, since the copying performance of a copying machine has been remarkably improved, it is possible to quickly and easily obtain a high-quality copy in which it is difficult to distinguish the difference from the original copy. became. Along with this, important documents, copies such as cash vouchers are copied,
New social problems such as misuse of the duplicates are increasing. Therefore, as a method to prevent inconvenient copying,
Conventionally, a warning mark, for example, "VOID" characters or the like is provided on a paper substrate according to JP-A-53-142237 using a fine screen, and the background tone larger than the above screen is used to make the mark normally invisible. When a copy-preventing printing base paper having a screen formed on the entire surface of a paper base from above the mark is used and an object to be copied having an information display portion on the base paper is copied, the above-mentioned display is displayed on the copy. There is a known method of preventing copying by displaying a warning mark "VOID" as a copy image in addition to the copy image corresponding to the copy, and it is usually impossible to visually check the display section below. A method is known in which a black seal having a function of visually observing the display portion when irradiated with ultraviolet rays is attached onto the display portion which is the specific information, and copying of the display portion is disabled to prevent copy. The It

[Problems to be solved by the invention]

However, in the above-mentioned copy prevention method, the former method forms a paper base material which has been subjected to copy prevention processing such as a warning mark in advance as a base paper for printing, and thereafter, prints and prints information such as important documents and cash vouchers on the base paper. Since all the information including confidential confidential information is copied and reproduced during copying, it is also necessary to appropriately select and position the display portion of the specific information that requires copy protection on the warning mark. Since it is difficult to remove the above-mentioned display portion at the time of copying because it is difficult, it is effective because it has a drawback that the warning mark appearing at the time of copying becomes difficult to identify when there is a large amount of information display portion. It is insufficient as a copy protection method. In the latter method, it is possible to easily prevent copying by simply attaching a black sticker on the display area of the specific information, but after attaching the sticker, in order to check the specific information of the original again, the ultraviolet irradiation device It has the inconvenience that it cannot be visually observed without using the above.

[Means for solving problems]

As a result of intensive studies conducted by the present inventors in view of the above problems, it is usually possible to visually observe the display portion of the specific information on the object to be copied, and when copying is performed, the original copy and the copy are copied. The present invention has been completed by finding a copy preventing method capable of clearly discriminating the difference between No. 1 and No. 3 and easily performing copy preventing processing at an arbitrary position on the display portion of the copy-receiving member.

That is, according to the present invention, (1) in an object to be copied having a display section for displaying information, a lower surface which is usually made of an uneven surface forming body or a non-homogeneous density body is formed on a display section of a portion where copying is to be prevented. Is provided with an optically transparent conversion medium composed of a hologram or a diffraction grating whose display part is visible, and corresponds to a portion provided with the optically transparent conversion medium of the display part of the copy object when the copy object is copied. (2) The optically transparent conversion medium is a hologram or a diffraction grating having a transparent thin film layer as a reflection layer, which is characterized in that the display portion of the copy is omitted, whitened, blackened or distorted. Above (1)
(3) Copy protection in which an optically transparent conversion medium is provided on the entire surface or a part of the display portion of a copy object having a display portion for displaying information on a base material. A medium, wherein the optically transparent conversion medium has a transparency capable of visually observing a display portion of a copy object therebelow, and is composed of a hologram or a diffraction grating composed of an uneven surface forming body or a non-homogeneous density body. When the copy object is copied, the display part of the copy corresponding to the part where the optically transparent conversion medium is provided in the display part of the copy object is missing, whitened, blackened or distorted. And (4) the copy protection medium according to the above (3), wherein the optically transparent conversion medium is a hologram or a diffraction grating having a transparent thin film layer as a reflection layer.

〔Example〕

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

In the present invention, the object to be copied has a base material 2 made of paper, synthetic resin, etc., a display section 3 for displaying general information formed on the base material 2, and a specific one which is inconvenient for reproduction. And a display unit 4 for displaying information. The copy preventing method according to the present invention comprises an optically transparent conversion medium 5 formed on at least the entire surface or a part of the display section 4 for displaying specific information of the object to be copied having the above-mentioned structure (copy preventing. The optical transparent conversion medium 5 provided on the display portion of the above-mentioned copy-preventing medium can normally see the display portion 4 below the medium 5, and When a copy prevention medium is placed on the platen of a copying machine and copied, the illumination light during copying is reflected irregularly by the optically transparent conversion medium and corresponds to the optically transparent conversion medium portion of the copy. The portion to be removed is formed so as to be missing, whitened, blackened, or distorted. The above-mentioned irregular reflection means that the amount of reflected light and the reflection position are different from the reflection of normal light. The irregular reflection reflects (scatters) a part of the light scattering function, regular reflection function, and irradiation light. Is obtained by an optically transparent conversion medium having a function of transmitting light. Below, above
The relationship between the function and the state of the copy by the function will be described.

As shown in FIG. 1, the optically transparent conversion medium 5 has a light scattering surface, and when the illumination light 7 from the light source unit 6 is reflected by the light scattering surface of the medium 5, scattered light 8 is generated, It has a function such that a part of the light enters the light receiving unit 9. Generally, in a normal black-and-white copying machine, a copy image of a copy becomes a white image as the amount of light received by the light receiving portion is larger in the positive-positive relationship, and conversely becomes a black image as the amount of light is smaller. Therefore, the copy image of the portion of the medium 5 on which the light scattering surface is formed becomes a white solid image and is whitened, and the whole or a part of the copy image of the display unit 4 at the position corresponding to the light scattering surface of the medium 5. Is missing.

As shown in FIG. 2, the optically transparent conversion medium 5 has a regular reflection surface, and the illumination light 7 from the light source unit 6 is regularly reflected on the regular reflection surface of the medium 5 (which reflects at the same angle as the incident angle). The specularly reflected light 10 does not enter the light receiving portion 9. Generally, in the structure of a copying machine, since the light receiving portion is installed at a position substantially vertically below the document table surface, the light specularly reflected does not enter the light receiving portion. Therefore,
The copy image of the portion of the medium 5 on which the specular reflection surface is formed becomes a black solid image and is blackened, and the copy image of the display unit 4 at the position corresponding to the specular reflection surface of the medium 5 is lost.

As shown in FIG. 3, the optically transparent conversion medium 5 has a function of partially reflecting (scattering) the illumination light 7 from the light source 6 on the surface of the medium 5 and partially transmitting the illumination light 7 to the inside of the medium 5. It is a thing. The light transmitted inside the medium is displayed on the display unit 4.
The light that has reached the position (1) and is reflected by the display unit 4 again passes through the inside of the medium and is scattered outside the medium. Therefore, in the above process, when the scattered light 8 is incident on the light receiving portion 9 in a large amount, a white solid image is obtained as a copied image, and the copied image corresponding to the display portion 4 is missing or the display portion 4 is missing. The corresponding copy image is obtained as a distorted image. On the contrary, when the amount of light incident on the light receiving unit 9 is small, a black solid image is obtained as the copied image and the copied image corresponding to the display unit is missing, or the copied image corresponding to the display unit is distorted image. Obtained as.

Examples of the optically transparent conversion medium 5 having the functions (1) to (3) include an uneven surface forming body and a non-homogeneous density body. Note that the flat laminated body can also obtain the above-mentioned effects as the optically transparent conversion medium, but the uneven surface forming body and the non-homogeneous density body are more excellent in the above-mentioned effects. For example, in the case of a flat laminated body, if the density of a copying machine is adjusted when copying an object to be copied, the image on the object to be copied may be uniformly reproduced even if it is incomplete. This is because, in the case of the planar laminate, since it is a uniform layer as a whole, the effects as the optically transparent conversion medium described in the above items 1 to 5 are uniformly exhibited. On the other hand, in the case of the uneven surface forming body and the non-homogeneous density body, a phase change or an amplitude change occurs in the reflected light of the illumination light due to its structure,
Uniform scattering and reflection cannot occur in the whole like a flat laminated body. Therefore, even if the image density of the copying machine is adjusted by using the uneven surface forming body and the non-homogeneous density body as the optically transparent conversion medium, the display portion is not uniformly copied. There is no possibility that the display section will be reproduced due to such reasons.

The uneven surface forming body has an uneven surface (light scattering surface) that scatters the illumination light, and the uneven surface may be located on the surface or inside the medium. Further, the uneven surface may be formed not only on the entire surface of the medium but also on a part thereof. Further, the above-mentioned formed body may be formed of a single layer, or may be formed of a multi-layered structure. FIG. 5 shows the medium 5 including the uneven surface forming body layer 12 in which the uneven surface 11 is located inside.

A hologram or a diffraction grating is used as the uneven surface forming body, and as the hologram, a Fresnel hologram, a Fraunhofer hologram, a lensless Fourier transform hologram, an image hologram, a rainbow hologram, a color hologram, a computer hologram, a hologram display, or a multi display. Plex holograms and the like, and examples of the diffraction grating include a holographic diffraction grating and a diffractive ornament.

As the method for obtaining the uneven surface forming body, a method of forming an uneven surface using a photoresist, a thermoplastic or the like, a method of forming an uneven surface by partial vapor deposition, molding, heat embossing, raised printing, engraving an uneven surface Examples of the method include a method of forming an uneven surface, a method of forming an uneven surface by a printing coating method such as letterpress, offset, gravure, screen, flexo, engraving intaglio, embossing, and a method of forming an uneven surface by mechanical processing / chemical processing. When the uneven surface forming body is a hologram, the hologram can be obtained by a conventionally known method. For example, when the hologram is a relief hologram, a hologram original plate on which interference fringes are recorded in a concave-convex shape is used as a press mold, a hologram-forming resin sheet is placed on the hologram original plate, and both are heated by a heating roll or other means. The hologram forming layer can be obtained by a method of pressing and replicating the uneven pattern of the hologram original plate on the surface of the hologram forming resin sheet.

Examples of the material for the uneven surface forming body include polyvinyl chloride, thermoplastic polyester, poly (meth) acrylate, polyvinyl acetate, polyethylene, polypropylene, polystyrene, polyvinylidene chloride, polyacrylonitrile, polycarbonate, cellulosic resin and polyurethane. Thermoplastic resin; phenol resin, urea resin, melamine resin, epoxy resin, alkyd resin, unsaturated polyester, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, polyol ( Meta)
A cured product of a thermosetting resin such as acrylate, melamine (meth) acrylate, or triazine acrylate; or a mixture of the above-mentioned thermoplastic resin and thermosetting resin, a copolymer, or the like can be used.

Further, as the above material, a thermoformable substance having a radically polymerizable unsaturated group can be used, and there are the following two types.

(1) Those having a radically polymerizable unsaturated group in a polymer having a glass transition point of 0 to 250 ° C. More specifically,
As the polymer, the following compounds 1) to 8) are polymerized or copolymerized, and the following methods (a) to (d) are described below.
Thus, a radical-polymerizable unsaturated group introduced can be used.

1) Monomer having hydroxyl group: N-methylol acrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,
2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate and the like.

2) Monomers having a carboxyl group: acrylic acid, methacrylic acid, acryloyloxyethyl monosuccinate, etc.

3) Monomer having epoxy group: glycidyl methacrylate and the like.

4) Monomers having an aziridinyl group: 2-aziridinyl ethyl methacrylate, allyl 2-aziridinyl propionate and the like.

5) Monomers having amino groups: acrylamide, methacrylamide, diacetone acrylamide, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like.

6) Monomer having sulfone group: 2-acrylamido-
2-methylpropanesulfonic acid and the like.

7) Monomer having isocyanate group: 2,4-toluene diisocyanate and 1-to-1-mol adduct of 2-hydroxyethyl acrylate, etc., and an adduct of a radical polymerization monomer having diisocyanate and active hydrogen.

8) Furthermore, in order to control the glass transition point of the above copolymer or the physical properties of the cured film, the above compound and the following monomer copolymerizable with this compound are used. It can also be copolymerized. Examples of such a copolymerizable monomer include methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, and t-methacrylate.
Examples thereof include butyl acrylate, t-butyl methacrylate, isoamyl acrylate, isoamyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate and the like.

Next, the hologram-forming resin can be obtained by reacting the polymer obtained as described above with the following methods (a) to (d) and introducing a radically polymerizable unsaturated group.

(A) In the case of a polymer or copolymer of a monomer having a hydroxyl group, a monomer having a carboxyl group such as acrylic acid or methacrylic acid is subjected to a condensation reaction.

(B) In the case of a polymer or copolymer of a monomer having a carboxyl group or a sulfone group, the above-mentioned monomer having a hydroxyl group is subjected to a condensation reaction.

(C) In the case of a polymer or copolymer of a monomer having an epoxy group, an isocyanate group or an aziridinyl group, the above-mentioned monomer having a hydroxyl group or a monomer having a carboxyl group is subjected to an addition reaction.

(D) In the case of a polymer or copolymer of a monomer having a hydroxyl group or a carboxyl group, a monomer having an epoxy group, a monomer having an aziridinyl group, or a diisocyanate compound and a hydroxyl group-containing acrylate monomer 1 to 1 mol of the adduct is subjected to an addition reaction.

In order to carry out the above reaction, it is preferable to add a trace amount of a polymerization inhibitor such as hydroquinone and to carry out it while sending dry air.

(2) A compound having a melting point of 0 to 250 ° C. and a radically polymerizable unsaturated group. Specific examples include stearyl acrylate, stearyl methacrylate, triacryl isocyanurate, cyclohexanediol diacrylate, cyclohexanediol dimethacrylate, spiroglycol diacrylate, and spiroglycol dimethacrylate.

Further, the above (1) and (2) may be mixed and used, and further, a radical polymerizable unsaturated monomer may be added thereto. This radically polymerizable unsaturated monomer is to improve the crosslink density and heat resistance upon irradiation with ionizing radiation, and in addition to the above-mentioned monomers, ethylene glycol diacrylate, ethylene glycol dimethacrylate, Polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, trimethylolpropane triacrylate,
Trimethylolpropane trimethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol hexamethacrylate, Ethylene glycol diglycidin ether diacrylate, ethylene glycol diglycidyl ether dimethacrylate, polyethylene glycol diglycidyl ether diacrylate, polyethylene glycol diglycidyl ether dimethacrylate, propylene glycol diglycidyl ether diacrylate, propylene glycol Diglycidyl ether dimethacrylate, polypropylene glycol diglycidyl ether diacrylate, polypropylene glycol diglycidyl ether dimethacrylate, sorbitol tetraglycidyl ether tetraacrylate, sorbitol tetraglycidyl ether tetramethacrylate, etc. can be used, and the above-mentioned copolymer Solid content of mixture
It is preferable to use 0.1 to 100 parts by weight with respect to 100 parts by weight. Further, although the above are sufficiently curable by electron beam, when cured by ultraviolet irradiation, benzoquinone as a sensitizer, benzoin, benzoin ethers such as benzoin methyl ether, halogenated acetophenones, biatyls. Those that generate radicals by irradiation with ultraviolet rays, such as, can also be used.

In the uneven surface forming body as described above, a transparent thin film layer may be provided on the uneven surface to enhance the light reflection effect. The thin film layer may be provided on a plane opposite to the uneven surface. When a transparent thin film layer is provided, the following is used as the layer.

(1) Transparent continuous thin film having a refractive index larger than that of the textured surface forming layer. There are transparent in the visible region and transparent in the infrared or ultraviolet region. The former is shown in Table 1 and the latter is shown in Table 1. Are shown in Table 2, respectively. In the table, n represents the refractive index (hereinafter,
The same applies to (2) to (5)).

(2) Transparent ferroelectric having a larger refractive index than the surface-roughened surface forming layer is shown in Table 3.

(3) Table 4 shows a transparent continuous thin film having a smaller refractive index than the textured surface forming layer.

(4) Reflective metal thin film having a thickness of 200Å or less The reflective metal thin film has a complex refractive index, and the complex refractive index: n *
Is represented by n * = n-iK. n is the refractive index and K is the absorption coefficient.

The material of the reflective metal thin film is shown in Table 5, and the above n and K are also shown in the same table.

Other materials include Sn, In, Te, Ti, Fe, Co, Zn, G
e, Pb, Cd, Bi, Se, Ga, Rb, etc. can be used. Further, oxides, nitrides, etc. of the above-mentioned metals can be used. Further, the metals, their oxides, nitrides, etc. can be used alone or in combination of two or more kinds.

(5) Resin with Different Refractive Index from Concavo-Convex Surface Forming Layer The refractive index may be higher or lower than that of the concavo-convex surface forming layer. Examples of these are shown in Table 6.

In addition to the above, general synthetic resins can be used, but a resin having a large difference in refractive index from the uneven surface forming body layer is particularly preferable.

(6) Laminated body obtained by appropriately combining the materials of (1) to (5) The combination of the materials of (1) to (5) is arbitrary, and the vertical positional relationship of each layer in the layer structure is also arbitrary. To be selected.

Among the above-mentioned thin film layers (1) to (6), the thickness of the thin film layer of (4) is 200 Å or less, but the thickness of the thin film layers of (1) to (3) and (5), (6). Is a transparent region of the material forming the thin film, and is generally preferably 10 to 10000Å, more preferably 100 to 5000Å.

By providing the above-mentioned thin film layers (1) to (6) on the uneven surface of the uneven surface forming body, the reflectance on the upper surface and the lower surface of the thin film layer is increased, and the irregular reflection effect by the uneven surface is increased. This effect depends on the difference in refractive index between the thin film layer and the uneven surface forming body layer, and the difference in refractive index is preferably 0.3 or more, more preferably 0.5 or more.

As a method for forming the thin film layer on the uneven surface forming body, when the thin film layer is made of the material of (1) to (4), a vacuum deposition method, a sputtering method, a reactive sputtering method, an ion plating method, an electric method. A general thin film forming means such as a plating method can be used, and when the thin film layer is made of the material (5), a general coating method or the like can be used. When the thin film layer is the material (laminate) of the above (6), the above-mentioned means, methods and the like are appropriately combined and used.

In the case of the material of the above (5), it is not necessary that the material is a thin film as long as it is a transparent material, and a resin layer having a thickness of the thin film or more may be provided on the uneven surface forming body layer.

When the uneven surface forming body is composed of only the hologram, it can be structured as a reflection hologram by the difference in the refractive index between air and the hologram forming resin.

Further, a protective layer may be provided on the uneven surface of the uneven surface forming body, and a protective layer may be provided on the thin film layer of the uneven surface forming body provided with the transparent thin film layer.

Examples of the planar laminate include those obtained by sequentially forming an adhesive layer, a transparent thin film layer, and a transparent resin layer. In this case,
Specular reflection of light occurs at the interface (regular reflection surface) between the transparent thin film layer and the adhesive layer. The thin film layer may be formed not only on the entire surface of the adhesive layer but also on a part thereof. As the material of the adhesive layer, a heat-sensitive adhesive, a pressure-sensitive adhesive or the like, and as the material of the transparent thin film layer, the same material as the material of the transparent thin film layer provided in the uneven surface forming body, the material of the transparent resin layer Examples of the material include the same materials as those of the above-mentioned uneven surface forming body.

The above-mentioned non-homogeneous density body refers to a planar body including a portion having different densities in the layer, that is, a portion having different refractive index of light, and the portions having different densities may be evenly dispersed or biased in the layer. May be. Examples of the non-homogeneous density material include silver salt photosensitive materials, photopolymers, photochromic materials, chalcogenides, photodielectric materials, electro-optical materials and the like.

The above-mentioned silver salt photosensitive material is, for example, a volume hologram formed by photographing a hologram on the silver salt photosensitive material and then bleaching it. This is a series of processes of exposure, development, fixing and bleaching. The refractive index of the photosensitive layer in the material is changed. PMMA as the photopolymer,
Photopolymer film (manufactured by Dupont) is used as photochromic materials such as spiropyrans, Na-doped CaF ₂ ,
Ni-doped CaTiO ₃ , Na-doped KCl and the like, and chalcogenides include TeAsGe crystals and the like. Further, as the light dielectric material PLZT (Pb-La-Zr- Ti), Bi 4 Ti 3 O 12 and the like, as the electro-optical material LiNbO _3: BaTiO _3, and the like. The electro-optic material causes a change in refractive index by causing electrons excited inside the ferroelectric crystal by strong light irradiation to be trapped in lattice defects or the like to generate a space charge electric field.

In order to provide the optically transparent conversion medium 5 having the functions (1) to (5) on the copy object 1 having the display portion 4 for displaying specific information, the part of the copy object 1 which is required to be prevented from being copied is coated,
Even if it is directly formed by laminating or the like, or if a medium transfer foil is formed and then it is provided by a transfer method, or even a medium label is formed, then it is provided by an adhesive method. Good.

An example of the structure of the medium transfer foil is shown in FIG. The medium transfer foil 13 shown in the figure has a release layer on the base film 14.
15, the uneven surface forming body layer 12, the transparent thin film layer 16, and the adhesive layer 17 are laminated in this order. As the material for the base film 14, polymer films such as polyethylene terephthalate, polyimide, polymethylmethacrylate, polystyrene, polyvinyl butyral, and polycarbonate, synthetic paper, metal films such as iron, and laminates thereof are used. The peeling layer 15 plays a role of imparting peelability between the base film 14 and the uneven surface forming body layer 12, and its material is acrylic resin, cellulose resin, vinyl resin, polyester resin, urethane resin. Examples of the resin include olefin resins, amide resins, and epoxy resins, and the film thickness is preferably 0.1 to 10 μm. Known materials for the adhesive layer 17 include conventional heat-sensitive adhesives such as acrylic resins, vinyl resins, polyester resins, urethane resins, amide resins, epoxy resins, rubber resins, and ionomer resins. A wide range of materials can be used, and the film thickness is preferably 1 to 100 μm.

The medium transfer foil 13 configured as described above is superposed on the object 1 to be copied from the adhesive layer at a position including the display portion 4 requiring copy protection, and the base film 14 is peeled off by heating and pressing to transfer the medium. The foil 13 is transferred to the object 1 (fifth)
Figure). Such a configuration has, for example, as shown in FIG. 4, a base material 2 configured as a check, a display portion 4 printed and displayed as a check holder authentication mark, and a base material 1 including the display portion 4. An object to be copied 1 including the optically transparent conversion medium 5 provided above is applied to an embodiment of the object to be copied used in the copy prevention method of the present invention. When the above-mentioned copy 1 composed of a check is copied, a copy 18 of the copy is obtained as a white solid image 19 of a part of the copy 5 on which the medium 5 is provided. The copy image of the unprinted portion is obtained as a normal copy image 20. Therefore, the copy image of the display portion 4 at the position corresponding to the medium 5, that is, the copy of the authentication stamp of the check holder, is missing, and the authentication stamp, which is the specific information, cannot be read.

An example of the structure of the medium label is shown in FIG. The medium label 21 shown in the figure is formed by laminating an uneven surface forming body layer 12, a transparent thin film layer 16, an adhesive layer 23, and a release paper 24 in this order on a base material sheet 22. The base sheet 22 is the uneven surface forming body layer 12
It protects the resin and also increases the mechanical strength of the whole. The material is polyethylene terephthalate, polyvinyl chloride, polyester resin, acrylic resin, epoxy resin, amide resin, urethane resin, polycarbonate. , Polystyrene or the like is used, and the film thickness is preferably 10 to 500 μm.

As the material of the pressure-sensitive adhesive layer 23, general pressure-sensitive adhesives such as acrylic type and rubber type are widely used. This pressure-sensitive adhesive is obtained by adding a tackifier to an elastic body, and as the elastic body, polyisoprene rubber, polyisobutyl rubber, SBR, a rubber system such as butadiene-acrylonitrile rubber, an acrylic ester system,
Examples of the tackifier include polyterpene resin, gum rosin, rosin ester and rosin derivative, oil-soluble phenol resin, coumarone indene resin, and petroleum hydrocarbon. In addition to the tackifier, a softening agent, a filler, an antiaging agent, etc. may be added. The film thickness of the adhesive layer 23 is preferably 0.1 to 50 μm.
As the release paper 24, silicone resin, wax, paraffins or the like coated on a base material such as paper or film is used.

The medium label 21 configured as described above can be provided by peeling off the release paper 24 and sticking it on the copy object 1 including the display portion 4 requiring copy protection via the adhesive layer 23.

The optically transparent conversion medium 5 is not limited to being provided on the smooth surface, and may be provided on the uneven surface as in the case of providing the character or the like on the display portion 4 in which the letter is embossed.

Substrate 1 that constitutes copy object 1 used in the present invention
The material of the paper is Japanese paper, kraft paper, Kurupak paper, crepe paper, corrugated paper, fine paper, OCR paper, MICR paper, foam paper, coated paper, art paper, synthetic paper, etc .; paper cloth paper, cloth cloth paper , Cover materials such as leather; polyvinyl chloride, thermoplastic polyester, polymethacrylate, polyvinyl acetate, polyacrylate, polyethylene, polypropylene, polystyrene, polyvinylidene chloride, polyacrylonitrile, polycarbonate, polyamide, polyurethane, polyimide, cellulose resin,
Plastics such as synthetic rubber-based resins, natural rubber-based resins, phenolic resins, urea resins, melamine resins, epoxy resins, alkyd resins, unsaturated polyester resins, and mixed resins or copolymer resins of suitable combinations thereof;
Rubber such as synthetic rubber and natural rubber; copper, iron, aluminum,
Tin, lead, and alloys with suitable combinations thereof;
Fibers such as cotton, staple fibers, synthetic fibers, glass fibers, and non-woven fabrics; wood and other wood-based materials; glass; and composite materials obtained by appropriately combining the above various materials are used.

The display unit 4 for displaying specific information refers to all visually appealing items, and is composed of information having a specific meaning that requires copy protection. Examples of such a display unit are images of characters, numbers, symbols, figures, patterns, tint blocks, etc .; device reading information such as barcodes, OCR, MICR, bittaders; personal identification information such as fingerprints, facial photographs, signatures; An identification mark such as a registered trademark; a company name mark, a certification mark such as a registration mark, and the like. Further, the display section may be a continuous printing layer provided by solid printing of an arbitrary hue.

As the display means of the display unit 4, 1) printing, 2) silver salt photograph, blueprint, diazo photograph, dichromated gelatin photograph, photoresist, photochromy, electrophotography, thermomagnetic recording, thermoplastic recording, 3) Display by hard copy means, for example, electro-sensitive recording such as electric discharge recording, electrolytic recording, electrostatic recording, current recording; pressure-sensitive recording using carbon or non-carbon; physical or chemical heat-sensitive recording, 4) Examples thereof include laser recording, holography, magnetic recording, engraving, embossing, display of paper making method, handwriting display, display display of liquid crystal and the like.

Examples of the specific copy object 1 composed of the base material 2 and the display unit 4 include cartons, containers, bags, cassette cases, cassette halves, floppy cases, wrapping paper and other packages; stock certificates, checks, Bills, securities, certificates,
Passcards, boarding tickets, wagon tickets, stamps, stamps, appreciation tickets, etc .; important documents such as registration documents, family register, abstracts, cash carts, credit cards, members' cards, greeting cards, postcards, business cards, IC cards Cards such as: Other forms, envelopes, tags, Shiori, calendars, posters, brochures, passports, POP supplies,
Coasters, displays, name plates, keyboards, cosmetics, accessories (clocks, lighters), stationery, building materials, radios, televisions, speakers, calculators, car instrument panels, emblems, keys, clothing, footwear, equipment OA
Equipment etc. are mentioned.

The present invention is not limited to copy prevention for copying by a black-and-white copying machine, but can be applied to copying by a color copying machine. When a copy object having a transparent copy preventing medium is copied by a color copying machine, Illumination light of three different wavelengths is sequentially irradiated to the copy object, and the function of the medium occurs for the illumination light of a specific wavelength of the illumination light, and the copy image of the display unit at the position corresponding to the medium. To prevent copying in the same manner as a black-and-white copying machine or with a high degree of content, for example, a copy is obtained in which the copy is missing or the copy image becomes an unclear image, and the copy has different color tones. Is possible.

The present invention is not limited to copying prevention by copying by a copying machine, and can also prevent copying by copying by a camera or the like.

Next, the present invention will be described in more detail with reference to specific examples.

Example 1 A mixed resin of acrylic resin and melamine resin (mixing weight ratio 4: 1) was applied on a polyethylene terephthalate film having a thickness of 200 μm to a thickness of 3 μm to form an uneven surface forming layer ( Refractive index n = 1.4), and the uneven surface is formed into a specific pattern by superimposing the hologram master plate by the hot pressing method, and then TiO ₂ is vacuum-deposited on the uneven surface to a thickness of 1200Å. A thin film was formed. Next, roll-coat a pressure-sensitive adhesive mainly composed of acrylic acid ester on the thin film to form a pressure-sensitive adhesive layer with a thickness of 20 μm, and then release paper that has been subjected to release treatment on one side is laminated on the pressure-sensitive adhesive layer. Lamination processing was performed to obtain a media label of an optically transparent conversion medium.

Peel off the release paper of the medium label and attach the medium label to the position including the entire surface of the display part, which is the important information of the important document,
When the important document was visually inspected, the display section below the medium could be visually inspected.

Next, when the above-mentioned important document was copied by a copying machine, a copy image of the portion corresponding to the position where the medium was provided was a white solid image having a specific pattern, and the display section was copied. Was not done.

〔The invention's effect〕

When a copy object having a display portion that requires copying is copied by implementing the copy prevention method of the present invention, the copy object is provided on the entire surface or a part of the copy object by the function of the optically transparent conversion medium. All or part of the illumination light that illuminates the display part is improperly reflected, and as a result, the copy image on the display part is lost, or whitening of a solid white image or blackening of a solid black image is performed. When the information is unreadable, or the copied image on the display unit becomes a distorted image, the information on the display unit becomes difficult to discriminate. Also, the difference between the original copy and the copy becomes clear.

Therefore, according to the present invention, inconvenient copying can be effectively prevented, and it becomes possible to prevent the copying of certificates, cash vouchers, or the like, or prevent the abuse of the copied material.

Further, according to the present invention, it is possible to selectively position and provide the medium at an arbitrary position on the copy object, and therefore it is possible to accurately prevent the copy of information that requires particularly confidential information. Further, even when a stamp, signature or the like is applied to a ready-to-be-copied object such as a certificate, a medium can be provided on the stamp or the signature after that, so that the information displayed later can be displayed. It is possible to effectively and accurately prevent copying.

Further, in the present invention, since the optically transparent conversion medium is composed of a hologram or a diffraction grating made of a textured surface forming body or a non-homogeneous density body, and the display section below the medium is usually visible, the visible light is not visible. When the optically transparent conversion medium itself is viewed with, the design peculiar to the hologram or the diffraction grating can be exhibited. For example, when a hologram is used as the optically transparent conversion medium, a hologram formed of interference fringes of arbitrary images such as characters and patterns is recorded, and when the optically transparent conversion medium provided on the copy is viewed, The image of can be reproduced. When the optically transparent conversion medium is a diffraction grating,
The interference light peculiar to the diffraction grating can be expressed. Thus, in the present invention, it is possible to provide the optically transparent conversion medium with a design peculiar to the hologram or the diffraction grating, and the design does not obstruct viewing of the display portion of the copy below. Is obtained.

Further, according to the present invention, since the optically transparent conversion medium composed of the hologram or the diffraction grating is used, the light radiated to the display section through the optically transparent conversion medium has the following unique effects. When the hologram or the diffraction grating is irradiated with light, the incident white light is spectrally dispersed with short wavelength light having a small diffraction angle and long wavelength light having a large diffraction angle. Further, in the hologram, in addition to the above-mentioned spectroscopy, a diffraction image due to interference is generated due to the diffractive property of the interference fringes of the hologram. Therefore, in the present invention, when the optically transparent conversion medium is irradiated with copy light, a diffraction image due to a hologram is generated or an interference color (interference fringe) due to a diffraction grating is generated, and these diffraction images are copied. It is recorded on the disc and is prevented from copying. Further, diffracted light is generated even if the incident angle of the incident light on the hologram or the diffraction grating changes. Therefore, even if the irradiation angle of the copying light is changed, a diffracted image is always generated, normal reflected light of the display unit cannot be obtained, and the display unit cannot be copied. That is, according to the present invention, the optically transparent conversion medium not only interferes with the reflection of the copying light due to its non-homogeneous density structure, surface irregularities, etc., but also produces a diffraction image by a hologram or a diffraction grating to copy the display section. Since it interferes, copying can be prevented more reliably as compared with a method of preventing copying by simply changing the reflection angle of the reflected light of the copy. Therefore,
According to the present invention, not only the effect of preventing copying by a black-and-white copying machine can be obtained, but also the effect of preventing copying by a color copying machine, copying by photography, and the like can be obtained.

[Brief description of drawings]

The drawings show an embodiment of copy protection according to the present invention, and FIGS. 1 to 3 are schematic diagrams showing different reflection states of illumination light at the time of copying due to different functions of the optically transparent conversion medium used in the present invention. FIG. 4 is a perspective view showing an embodiment in which a medium is provided on a copying medium by transfer, FIG. 5 is a vertical sectional view taken along line VV of FIG. 4, and FIG. 6 is a copying medium of the copying medium shown in FIG. FIG. 7 is a perspective view showing a copy, and FIG. 7 is a vertical sectional view of a medium label. 1 ... Copying object, 2 ... Display section 5 ... Optical transparent conversion medium 7 ... Illumination light

Claims (4)

[Claims] 1. A display unit of a portion to be prevented from being copied in a body to be copied having a display unit for displaying information,
An optically transparent conversion medium consisting of a hologram or a diffraction grating, which is usually made up of an uneven surface forming body or a non-homogeneous density body and in which the lower display section is visible, is provided, and when a copy object is copied,
A method for preventing copying, which comprises removing, whitening, blackening or distorting a portion of the display portion of the copy corresponding to the portion of the display portion of the copy object provided with the optically transparent conversion medium. 2. The copy protection method according to claim 1, wherein the optically transparent conversion medium is a hologram or a diffraction grating having a transparent thin film layer as a reflection layer. 3. A copy protection medium in which an optically transparent conversion medium is provided on the entire surface or a part of the display part of a copy object having a display part for displaying information on a base material. The optically transparent conversion medium is transparent so that the display portion of the copy object therebelow can be visually observed, and is composed of a hologram or diffraction grating made of an uneven surface forming body or a non-homogeneous density body. When the body is copied, the portion of the display portion of the copy corresponding to the portion where the optically transparent conversion medium of the display portion of the copy object is provided is omitted or whitened or blackened or distorted. Copy protection media. 4. The copy protection medium according to claim 3, wherein the optically transparent conversion medium is a hologram or a diffraction grating having a transparent thin film layer as a reflection layer.