JPH06247084A - Diffraction pattern recording medium and method of authenticating the same - Google Patents

Abstract

PURPOSE:To provide a diffraction pattern recording medium, which can be authenticated by a card processing device having an optically reading means and is hardly forged and falsified, and a method of authenticating the medium. CONSTITUTION:A diffraction pattern recording medium comprises: a relief layer 3 consisting of a resin layer 1, on which a diffraction pattern is recorded as a recess and protrusion pattern, and a thin film layer 2, which is formed on the surface of the resin layer 1 having thereon the recess and protrusion pattern, has refractive index different from that of the resin layer 1 and is capable of transmitting visible rays and infrared rays; a concealing layer 4, which substantially transmits the infrared rays and does not transmit the visible rays; and an infrared ray absorbing part 6 or a printed part consisting of a reflecting part, each being laminated on one another in order. Authentication of the medium is done by a method of certifying the infrared rays through the relief layer 3 and the concealing layer 4, reflecting the infrared rays from the printed part, detecting the rays reflected again through the concealing layer 4 and the relief layer 3 with an infrared ray detecting device, and reading the pattern such as a symbol, a letter, a code, etc., recorded on the printed part 8, whereby the diffraction pattern recording medium is identified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a relief hologram,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium such as a card, a certificate, a passbook, a passport, a recording medium in which a light diffraction pattern such as a diffraction grating is recorded and whose authenticity is guaranteed, a transfer sheet and a seal recording medium, and an authentication method thereof.

[0002]

2. Description of the Related Art Conventionally, holograms and the like are attached to cash cards, credit cards, prepaid cards, securities, passbooks, passports, etc. to guarantee the authenticity and give the cards design. The guarantee of authenticity utilizes the difficulty of forgery of the hologram, and the authenticity of the card or the like to which the hologram is attached is confirmed by visual authentication.

As described above, the function of the hologram used in the conventional cash card or the like is mainly to provide visual authenticity or to give a design property, and if not a skilled person, a rigorous appraisal is performed. However, it has no function at all regarding fraud prevention and authentication in an unmanned card processing device. Therefore, the applicant of the present invention has disclosed that
-283383-5, JP-A-63-61386, JP-A-63-168397, and JP-A-63-
As described in 206791, JP-A-63-207696, JP-A-1-142784, etc., the hologram reproduced image itself is recognized by an optical sensor to confirm the authenticity of a card or the like. I made a suggestion.

[0004]

However, although relief holograms and the like that have been conventionally used have the characteristic that they are difficult to forge, since they are duplicated by embossing, variable information (for example, serial number) for individual identification should be added. In that case, the plate must be changed and embossed each time, and basically, only the same picture and information can be given, and the variable information can be recorded in a magnetic recording unit or an area different from the hologram. It is necessary to record in the print recording section, and there is a large restriction on the space above the card and the design. In addition, since the variable information is recorded in a region different from that of the hologram, the variable information may be rewritten, and the characteristic of the hologram that is difficult to forge does not guarantee the authenticity of the variable information itself.

The present invention has been made in view of such circumstances, and an object thereof is an optical diffraction pattern which can be authenticated by a processing device such as a card having an optical reading means and which is difficult to forge or alter. A recording medium and its authentication method are provided.

[0006]

A light-diffraction pattern recording medium of the present invention which achieves the above-mentioned object is at least a relief layer in which a light-diffraction pattern is recorded as a concavo-convex pattern, which is substantially visible through infrared light. The concealing layer that does not transmit light, and the printing section including the infrared light absorbing section or the reflecting section are sequentially laminated.

The relief layer is formed on the surface of the resin layer on which the light diffraction pattern is recorded as an uneven pattern or on the surface of the resin layer on which the uneven pattern is recorded, and has a refractive index different from that of the resin layer. However, it may be composed of a thin film layer capable of transmitting visible light and infrared light.

In this case, the printing section composed of the infrared light absorbing section or the reflecting section can be constituted by the infrared light reflecting layer and the infrared light absorbing printing located on the concealing layer side, or the infrared light absorbing section. It may also consist of a layer and an infrared light reflection printing located on the side of the hiding layer.

In addition, this optical diffraction pattern recording medium can be formed into a transfer sheet by providing a peelable support on the relief layer side, and the peelable support can be provided on the printing section side via an adhesive layer. It may be provided to form a seal.

Further, the method for authenticating a light diffraction pattern of the present invention comprises at least a printing layer composed of a relief layer in which the light diffraction pattern is recorded as a concavo-convex pattern, an infrared light absorbing portion or a reflecting portion, which are sequentially laminated. A method of authenticating a light-diffraction pattern recording medium, which comprises irradiating infrared light through the relief layer and a masking layer, patterned and reflected by the printing unit, and transmitted through the masking layer and the relief layer again. It is a method characterized in that the light diffraction pattern recording medium is identified by detecting emitted light with an infrared light detection device and reading a pattern of symbols, characters, codes, etc. recorded in the printing section. .

In this case, the relief layer is illuminated with visible light of a predetermined wavelength, the pattern diffracted from the relief layer is detected by a visible light detector, and the detection signal and the detection signal detected by the infrared light detector are detected. It is also possible to identify the optical diffraction pattern recording medium based on the detection signal detected by the visible light detection device.

[0012]

In the present invention, at least the relief layer in which the light diffraction pattern is recorded as a concavo-convex pattern, the concealing layer which substantially transmits infrared light and does not transmit visible light, the infrared light absorbing portion or the reflecting portion. Since the printed portions are sequentially laminated, only the light diffraction pattern recorded on the resin layer and the thin film layer can be seen from the outside, and the print information therebelow cannot be seen. By illuminating infrared light and detecting and identifying the print information under the concealment layer by the infrared light detection device, it becomes possible to individually identify the hologram sheet with a processing device such as a card having an optical reading means. . In addition, since the relief layer and the printing section are laminated, the restriction on the design space is greatly reduced, and the design is high. Also,
Alter the information of either the laminated relief layer or the printing section,
If you try to tamper with it, the other information will be damaged and its history will be revealed.

[0013]

Embodiments of the optical diffraction pattern recording medium and the authentication method thereof according to the present invention will be described below with reference to the drawings. As the light diffraction pattern recorded as the uneven pattern, it is possible to record a relief hologram or a relief diffraction grating in which the light intensity distribution of the interference fringes due to the interference between the object light and the reference light is recorded in the uneven pattern. Holograms, Fraunhofer holograms, lensless Fourier transform holograms, laser holograms such as image holograms, and white light holograms such as rainbow holograms, as well as color holograms, computer holograms, hologram displays, multiplex holograms that utilize these principles. Examples include holographic stereograms and holographic diffraction gratings that use hologram recording means.Other than that, mechanical diffraction gratings can be created using electron beam drawing devices, etc. Can also be mentioned the diffracted light hologram or diffraction grating is obtained, and these may be recorded in a single or multiple. These holograms or diffraction gratings are generally transmissive (the incident side of illumination light and the observer's viewing side are opposite sides of the hologram or diffraction grating, and are opposite sides), and a thin film layer is formed on the surface having an uneven pattern. Reflective by providing (the incident side of illumination light and the observer's observation side are the same side with respect to the hologram or diffraction grating)
Becomes

In the present invention, the light diffraction pattern recorded as the uneven pattern as described above is used, and print information readable by infrared light is arranged under the light diffraction pattern through the hiding layer which is transparent to infrared light. Therefore, only the information recorded as a highly-diffractive light diffraction pattern is visible on the outside, and the authentication of the light-diffraction pattern recording medium is to read the print information under the concealment layer by infrared light. . Hereinafter, the present invention will be described based on examples.

FIG. 1 is a sectional view of an embodiment of a card-shaped optical diffraction pattern recording medium according to the present invention, in which a thin film is formed on the surface of a transparent resin layer 1 on which an optical diffraction pattern is recorded as an uneven pattern. Infrared absorption printing 6 on the relief layer 3 having the layer 2 formed thereon, the concealing layer 4 that substantially transmits infrared light and does not transmit visible light, the adhesive layer 5, and the substrate 7 that reflects infrared light 6
The printing unit 8 on which the variable information is formed is sequentially stacked.

The light diffraction pattern is formed by using a hologram or a diffraction grating by using a photosensitive resin, a thermoplastic, or the like.
Once expressed in the form of concavities and convexities as a relief hologram or relief diffraction grating, the relief hologram or relief diffraction grating obtained is molded by plating etc. to create a mold or resin mold and used to synthesize. It is possible to mass-reproduce relief holograms or relief diffraction gratings by a molding method for resins. The resin layer 1 is made of a moldable synthetic resin and has a thickness of about 0.4 to 4 μm, preferably 1 to 2 μm.

Examples of the moldable synthetic resin include the following. Thermoplastic resin such as polyvinyl chloride, acrylic (eg, MMA), polystyrene, polycarbonate, unsaturated polyester, melamine, epoxy, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth ) Acrylate, polyol (meth)
A cured product of a thermosetting resin such as acrylate, melamine (meth) acrylate, or triazine-based acrylate, or a mixture of the above-mentioned thermoplastic resin and thermosetting resin can be used.

Further, as a moldable synthetic resin, a thermoformable substance having a radical polymerizable unsaturated group can be used, and there are the following two types. (1) A polymer having a glass transition point of 0 ° C to 250 ° C and having a radically polymerizable incompatible group in the polymer. More specifically, as the polymer, a polymer obtained by polymerizing or copolymerizing the following compounds can be used in which a radically polymerizable unsaturated group is introduced by any of the following methods (a) to (d). Monomers having hydroxyl groups: 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 acrylate, 2-hydroxy-3-phenoxypropyl methacrylate and the like. Monomers having a carboxyl group: acrylic acid, methacrylic acid, acryloyloxyethyl monosuccinate, etc. Monomers having epoxy groups: glycidyl methacrylate and the like. Monomers having an aziridinyl group: 2-aziridinylenyl methacrylate, allyl 2-aziridinylpropionate and the like. Monomers having amino groups: acrylamide, methacrylamide, diacetone acrylamide, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like. Monomers having sulfone groups: 2-acrylamido-2-methylpropanesulfonic acid, etc. Isocyanate group-containing monomer: 2,4-toluene diisocyanate and 2-hydroxyethyl acrylate, such as a 1 mol to 1 mol adduct of diisocyanate and a radical-polymerizable adduct having active hydrogen. Further, in order to control the glass transition point of the above copolymer or to control the physical properties of the cured film, the above compound and a copolymerizable monomer such as You can also let it. Such copolymerizable monomers include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate,
Butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, isoamyl acrylate, isoamyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate,
2-ethylhexyl acrylate, 2-ethylhexyl methacrylate and the like can be mentioned.

Next, the polymer obtained as described above is reacted according to the following methods (a) to (d) to introduce a radically polymerizable unsaturated group to obtain a material according to the present invention. be able to. (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 body of 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 send it by sending dry air.

(2) A compound having a radically polymerizable unsaturated group having a melting point of 0 ° C to 250 ° C. Specifically, stearyl acrylate, stearyl methacrylate,
Examples thereof include triacryl isocyanurate, cyclohexanediol diacrylate, cyclohexanediol dimethacrylate, spiroglycol diacrylate, and spiroglycol dimethacrylate. Moreover, the above-mentioned (1) and (2) can be mixed and used as the moldable synthetic resin, and a radical-polymerizable unsaturated monomer can be added to them. This radically polymerizable unsaturated monomer improves the crosslink density upon irradiation with ionizing radiation, and in addition to the above monomers, ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate,
Polyethylene glycol dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, pentaerythritol triacrylate, pentaerythritol Trimethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, ethylene glycol diglycidyl ether diacrylate, ethylene glycol diglycidyl ether dimethacrylate, polyethylene glycol diglycidyl ether diacrylate, polyethylene glycol diglycol Diethyl 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 it is preferable to use 0.1 to 100 parts by weight with respect to 100 parts by weight of the solid content of the above-mentioned copolymer mixture. Further, the above can be sufficiently cured by electron beam, but when cured by irradiation with ultraviolet rays, benzoquinone as a sensitizer, benzoin, bunzoin ethers such as benzoin methyl ether, halogenated acetophenones, Those that generate radicals upon irradiation with ultraviolet rays, such as biacetyls, can also be used.

In order to form the relief hologram or the relief diffraction grating on the resin layer 1 by using the above-mentioned moldable synthetic resin, a conventionally known method can be used. As a mold for forming a relief hologram or a relief diffraction grating, (1) one in which interference fringes of object light and reference light are formed on a photoresist in the form of unevenness by exposure and development, (2) By performing silver plating or nickel plating on the uneven side (mold surface) of the above (1),
A mold in which the irregularities of (1) above are duplicated, and (3)
Any of resin molds or the like in which the mold surface irregularities of the molds of (1) or (2) above are duplicated with a synthetic resin can be used, and these molds are duplicated in large numbers by an appropriate means to perform an appropriate arrangement to form a composite mold. Therefore, it is preferable that many relief holograms or relief diffraction gratings can be duplicated in one molding step. In addition, when making a mold with a synthetic resin, a thermosetting or ionizing radiation-curable synthetic resin is used as the material of the mold in the sense of improving the wear resistance of the mold and the heat resistance of the mold when hot pressing. Good to use.

The thin film layer 2 imparts reflectivity to the light diffraction pattern of the resin layer 1, and is made of Cr, Ti, Fe, C.
o, Ni, Cu, Ag, Au, Ge, Al, Mg, S
b, Pb, Pd, Cd, Bi, Se, Sn, In, G
Metals such as a and Rb and oxides and nitrides thereof are used alone or in combination of two or more. Of these metals, Al, Cr, Ni, Ag, Au and the like are particularly preferable. The thin film layer 2 can be formed by a method such as vapor deposition, sputtering, ion plating, CVD, or plating, and the thickness thereof is preferably 200 to 1000Å.

Alternatively, the above-mentioned metal, metal oxide,
Alternatively, if a continuous thin film of a substance having a refractive index different from that of the resin layer 1 is provided in addition to a thin film of metal nitride alone or in combination, such a film itself can be used although it is transparent. Among them, those having a refractive index larger than that of the transparent layer (hereinafter, the refractive index: n is added in parentheses to the right of the material name), Sb ₂ S ₃ (n = 3.0), Fe ₂ O
₃ (n = 2.7), TiO ₂ (n = 2.6), CdS
(N = 2.6), CeO ₂ (n = 2.3), ZnS (n
= 2.3), PbCl ₂ (N = 2.3), Sb ₂ O
₃ (n = 2.0), WO ₃ (n = 2.0), SiO (n
= 2.0), In ₂ O ₃ (n = 2.0), PbO (n =
2.6), Ta ₂ O ₅ (n = 2.4), ZnO (n =
2.1), ZrO ₂ (n = 2.0), Cd ₂ O ₃ (n =
1.8), Al ₂ O ₃ (n = 1.6), CaO · SiO
₂ (n = 1.8) and the like. The continuous thin film preferably has a refractive index higher than that of the resin layer 1 by 0.3 or more, more preferably 0.5 or more. According to the experiments conducted by the present inventors, it has been found that the optimum value is 1.0 or more.

The film thickness may be in the transparent region of the material forming the thin film layer 2, but normally 10 to 1000 Å is preferable.
As a method for forming the thin film layer 2 on the relief forming surface of the resin layer 1, general thin film forming means such as a vacuum vapor deposition method, a sputtering method, a reactive sputtering method and an ion plating method can be adopted. If a continuous thin film with a large refractive index is provided in this way, due to the angle dependence of reproduction that is a feature of holograms and diffraction gratings, it cannot be seen as a transparent body outside the reproducible angle range of holograms and diffraction gratings, and holograms and Within the reproducible angle range of the diffraction grating, the light reflectance is maximized, and the effect as a reflective hologram or diffraction grating comes out.

The above continuous thin film may have a refractive index smaller than that of the transparent layer, such as LiF (n = 1.4), M
gF ₂ (n = 1.4), 3NaF · AlF ₃ (n = 1.
4 or 1.2), AlF ₃ (n = 1.4), CaF
₂ (n = 1.3 or 1.4), NaF (n = 1.
3) etc. are illustrated. Alternatively, a transparent strong derivative having a refractive index larger than that of the transparent layer can be used as well, and CuCl (n
= 2.0), CuBr (n = 2.2), GaAs (n =
3.3-3.6), GaP (n = 3.3-3.5), N
₄ (CH ₂ ) ₆ (n = 1.6), Bi ₄ (GeO ₄ )
(N = 2.1), KH ₂ PO ₄ (KDP) (n = 1.
5), KD ₂ PO ₄ (n = 1.5), NH ₄ H ₂ PO ₄
(N = 1.5), KH ₂ AsO ₄ (n = 1.6), Rb
H ₂ AsO ₄ (n = 1.6), BaTiO ₃ (n = 2.
4), KTa _0.65 Nb _0.35 O ₃ (n = 2.3), K _0.6
Li _0.4 NbO ₃ (n = 2.3), KSr ₂ Nb ₅ O ₁₅
(N = 2.3), Sr _X Ba _1-X Nb ₂ O ₆ (n = 2.
3), Ba ₂ NaNbO ₁₅ (n = 2.3), LiNbO
₃ (n = 2.3), LiTaO ₃ (n = 2.4), Sr
TiO ₃ (n = 2.4), KTaO ₃ (n = 2.2) and the like are exemplified.

Further, a transparent synthetic resin layer having a refractive index different from that of the resin layer 1 may be used as the thin film layer 2, and concrete synthetic resins are as follows.
Polytetrafluoroethylene (refractive index; n = 1.35),
Polychlorotrifluoro (n = 1.43), polyvinyl acetate (n = 1.45 to 1.47), polyethylene (n =
1.50 to 1.54), polypropylene (n = 1.4
9), polymethylmethacrylate (n = 1.45), polystyrene (n = 1.60), polyvinylidene chloride (n
= 1.60 to 1.63), polyvinyl butyral (n =
1.48), polyvinyl formal (n = 1.50),
Polyvinyl chloride (n = 1.52 to 1.55), polyester (n = 1.52 to 1.57).

The hologram or diffraction grating in the present invention basically has the resin layer 1 having the irregularities of the hologram or diffraction grating on the lower surface as described above, and the thin film layer 2 on the lower surface of the resin layer 1. It may be composed of a resin layer having an irregular surface of a hologram or a diffraction grating on its upper surface and a thin film layer provided in contact with the irregular surface of the hologram or the diffraction grating.

The hiding layer 4 is a cellulose derivative such as ethyl cellulose, ethyl hydroxyethyl cellulose, cellulose acetate propionate or cellulose acetate,
Styrene resin such as polystyrene and poly-α-methylstyrene, or styrene copolymer resin, acrylic resin or methacrylic resin such as polymethylmethacrylate, polyethylmethacrylate, polyethylacrylate, polybutylacrylate, etc. Binders such as coalesce, rosin, rosin-modified maleic acid resin, rosin-modified phenolic resin, rosin ester resin such as polymerized rosin, polyvinyl acetate resin, coumarone resin, vinyltoluene resin, vinyl chloride resin, polyester resin, polyurethane resin, butyral resin , For example, MS Red G
P, Macrolex Red Violet R, C
eres Red 7B, Samaron Red H
BSL, Resolin Red F3BS (above, red dye), Holon Brilliant Yellow 6GL, PTY
-52, Macrolex Yellow 6G (above, yellow dye), Cassette Blue 714, Waxolin Blue AP-
FW, Holon Brilliant Blue SR, MS Blue 1
Various pigments and dyes that transmit infrared light but not visible light such as 00 (above, blue dye) are added, and if necessary, plasticizer, stabilizer, wax, grease, desiccant, drying auxiliary agent Ordinary gravure method, roll method, knife edge method, offset method, etc., using a paint or ink prepared by adding a curing agent, thickener, dispersant, and then thoroughly kneading with a solvent or diluent. A desired portion can be formed by a method or a printing method. Note that the concealing layer 4 is formed in a single color, and may be formed in a desired pattern, character, tint block, pattern or the like by using dyes or pigments of a plurality of colors.

As the adhesive layer 5, various types of adhesives can be used for this purpose, and the following adhesives are exemplified. Phenolic resin, furan resin, urea resin, melamine resin, polyester resin, polyurethane resin, epoxy resin or other thermosetting resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl chloride resin, polyvinyl resin Butyral resin, poly (meth) acrylic resin, nitrocellulose, polyamide or other thermoplastic resin, butadiene-acrylonitrile rubber, neoprene rubber or other rubber, or glue, natural resin, casein, sodium silicate,
One or two of dextrin, starch, gum arabic, etc.
Adhesives based on more than one species may be used.
Further, these adhesives may be any of a solution type, an emulsion type, a powder type, a film type and the like, and further may be a room temperature solidification type, a solvent volatilization solidification type, a melt solidification type and the like.

Further, in the present invention, what is called a pressure-sensitive adhesive as an adhesive, for example, an acrylic resin, an acrylic ester resin, or a copolymer thereof, a styrene-butadiene copolymer, a natural rubber, casein, gelatin, Rosin ester, terpene resin, phenol resin, styrene resin, chromanindene resin, xylene, aliphatic hydrocarbon, polyvinyl alcohol, polyethylene oxide, polymethylene oxide, polyethylene sulfonic acid, etc. can be used, and the adhesiveness by heating A heat-sensitive adhesive to be applied (in other words, heat seal agent) can also be used. The material constituting the heat-sensitive adhesive, polyethylene, polyvinyl acetate, or copolymers thereof, acrylic resin or ethylene-acrylic acid copolymer, polyvinyl butyral, polyamide, polyester, plasticized chloroprene, polypropylene, polyvinyl ether, Examples thereof include thermoplastic resins such as polyurethane, cellulosic resins, waxes, paraffins, rosins and asphalts, and uncured thermosetting resins such as epoxy resins and phenol resins. The thickness of the adhesive layer 5 is 4
It is preferably about 20 to 20 μm.

The infrared light absorption printing 6 is made of a binder that can be used for the hiding layer 4, such as carbon black, blackened silver,
Add various pigments and dyes that absorb infrared light, such as cyanine dyes, phthalocyanine dyes, natoquinone dyes, anthraquinone dyes, zirol dyes, triphenylmethane dyes, etc. Agents, stabilizers, waxes, greases, desiccants, drying aids, curing agents, thickeners, dispersants, and then kneaded sufficiently with a solvent or diluent to prepare a paint or ink. The desired portion can be formed by a printing method such as a gravure method, an offset method, a silk method, a thermal transfer method using a thermal head, a sublimation transfer method, an inkjet method, or an electrostatic adsorption method.

The base material 7 has a heat resistance required as a base material,
Considering strength, rigidity, hiding power, light opacity, etc., nylon, cellulose diacetate, cellulose triacetate, polyvinyl chloride, polystyrene, polyethylene, polypropylene, polyester, polyimide, resins such as polycarbonate, copper, aluminum, etc. It can be composed of a composite of materials selected appropriately from materials such as metal, paper, and impregnated paper, either alone or in combination. The thickness of such a base material can be about 0.005 mm to 5 mm. As the base material 7 that reflects infrared light, white or light-colored paper such as high-quality paper, white or light-colored synthetic resin such as polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, or the above-mentioned synthetic resin may be attached to the paper. Synthetic paper such as carton paper and coated paper, which are coated composite materials. In addition, fast yellow G, fast yellow 10G, disazo yellow AAA, disazo yellow AAMX, disazo yellow AAOT (above, yellow pigment), toluidine red, naphthol carmine FB, naphthol red M, vilarozone red (above, red pigment) ), Victoria Pure Blue BO Rake, Boussy Blue 5B Rake, Fast Sky Blue, Alkali Blue G Toner, Reflex Blue (above, blue pigment), Aniline Black, Iron Black, Format Ink (magenta + cyan) (above, Black Pigment), zinc white, titanium white, calcium carbonate, barium sulfate, alumina white (above, white pigment) and the like, which reflects infrared light by applying or printing a paint or ink containing a material that reflects infrared light. Base material 7 It is possible to, also, may be kneaded into a synthetic resin constituting the base material 7 which reflects infrared light.

In the light diffraction pattern recording medium having such a structure, only the information of the light diffraction pattern recorded in the relief layer can be visually observed at a predetermined observation angle, and the information below the concealing layer 4 cannot be seen. Therefore, when infrared light is irradiated from the relief layer 1 side, the infrared light passes through the relief layer 3 and the masking layer 4 and reaches the printing portion 8. The infrared light that is absorbed according to the information of the infrared light absorption printing 6 and is reflected by the base material 7 that reflects the infrared light is
It comes out through the concealing layer 4 and the relief layer 3. An optical sensor 10 that detects only infrared light is arranged, and a machine-readable bar code, symbol, or the like as information of the infrared light absorption printing 6 is provided.
By using the variable information such as characters, the information of the infrared light absorption printing 6 can be read by the processing device such as an unattended card and the individual identification of the optical diffraction pattern recording medium 9 such as the card becomes possible.

In the case of FIG. 1, the printing section 8 uses the infrared light absorption printing 6, but it may perform the infrared light reflection printing. In that case, instead of the base material 7 that reflects infrared light, nylon, cellulose diacetate, polyvinyl chloride, polystyrene, polyethylene, polypropylene,
Polyester, polyimide, resins such as polycarbonate, or carbon black, blackened silver, cyanine dyes, phthalocyanine dyes, natoquinone dyes, anthraquinone dyes, zirol dyes on these resins,
A base material that absorbs or transmits infrared light in which a dye such as a triphenylmethane dye is mixed is used. Also, the hiding layer 4
Need not necessarily be black, but may be other colors including white. However, if the concealing layer 4 is a light color, the diffracted light from the light diffraction pattern becomes difficult to see, and if the information is used as authentication information as described later, it becomes difficult to read, which is not desirable. Further, the resin layer 1 has 1
In addition to individual information, multiple pieces of information may be recorded in multiple such as changing the incident angle of the reference light at the time of shooting.

In the above, only the information of the infrared light absorption print 6 under the concealing layer 4 is used for the authentication by the mechanical reading of the optical diffraction pattern recording medium, and the information of the relief layer 3 is the visual authentication information and other information. Although it was supposed to be used as other information in the design, the machine-reading authentication information is recorded in the relief layer 3 and read by another optical sensor 11 that detects this information and read by the optical sensor 10. By performing synchronization, collation, etc. with the information of the infrared light absorption printing 6, it becomes possible to perform more advanced authentication. An example of the signal processing is shown in FIG. In this case, the same bar code pattern is used as the print pattern 6'of the infrared light absorption printing 6 and the information pattern 3'of the relief layer 3, and in this case, it is obtained from both photosensors 10 and 11. Input the read signal to the AND circuit 12, and only when both match
The authentication signal is output. Therefore, if either the relief layer 3 or the infrared light absorption printing 6 is altered or tampered with, the authentication information can no longer be read, and high-level authentication becomes possible. Of course, in the above, the information recorded in the relief layer 3 and the infrared light absorption printing 6 need not be the same, and the processing of the signals of both is not limited to the collation by the AND circuit as described above. Various known methods can be adopted.

The above is the case where the optical diffraction pattern recording medium of the present invention is constructed in the form of a card. As shown in FIG. 4, the releasability of the transfer support 13 having the release layer 14 formed on one side is shown. A relief layer 3, a concealing layer 4, an adhesive layer 5, and an infrared light absorbing print 6 are sequentially laminated on a support 15 via a protective layer 15 to form a transfer sheet-like optical diffraction pattern recording medium. You can also When the transfer support 13 has releasability, the release layer 14 can be omitted, and if the relief layer 3 itself is tough, the protective layer 16 can be omitted. The transfer support 13 is made of the same material as the above-mentioned base material. The peeling layer 14 is made of a resin having a weak adhesive property with the resin layer or the protective layer, and specifically, a polymethylmethacrylate resin and another thermoplastic resin such as vinyl chloride vinyl acetate copolymer, nitrocellulose. resin,
And a mixture of polyethylene wax or a mixture of cellulose acetate resin and thermosetting acrylic resin or melamine resin. The protective layer 16 can be formed by laminating a synthetic resin film, an extrusion coating method, or applying a synthetic resin paint. In addition, the surface can be made releasable by adding silicone or the like to the protective layer 16.
It should be noted that if the printed portion composed of the infrared light absorption printing 6 is formed in the lowermost layer, the printed portion can be formed immediately before the transfer, which is an optimal place for forming the individual identification information.

Further, as shown in FIG. 5, the peelable support 1
It is also possible to provide 7 on the opposite side of the adhesive layer 5 from the relief layer 3 to form a seal. In this case, the releasable support 17 is peeled off and the adhesive layer 5 on the peeling side is attached to the adherend.

The optical diffraction pattern recording medium of the present invention and the authentication method thereof have been described above based on the embodiments, but the present invention is not limited to these embodiments and various modifications can be made.

[0038]

As is apparent from the above description, according to the optical diffraction pattern recording medium and the authentication method thereof of the present invention,
At least a relief layer in which a light diffraction pattern is recorded as a concavo-convex pattern, a concealing layer that substantially transmits infrared light and does not transmit visible light, and a printing section including an infrared absorption section or a reflection section are sequentially laminated. Therefore, only the recorded information on the relief layer can be seen, and the printed information below it cannot be seen. By irradiating infrared light and detecting the information of the printing portion under the relief layer by the infrared light detection device, it becomes possible to identify the individual optical diffraction pattern recording medium by a processing device such as an unattended card. Also, since the relief layer and the printing section are laminated, the restrictions on the design space are greatly reduced,
An adherend having a high design property can be obtained. Further, if one tries to alter or falsify information on either the laminated relief layer or the printing portion, the other information is damaged, and the history thereof becomes clear.

It is also possible to detect the information recorded on the relief layer and the information recorded on the printing section at the same time, and perform higher-level authentication by performing signal processing such as synchronization of both detection signals and collation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of an optical diffraction pattern recording medium on a card according to the present invention.

FIG. 2 is a diagram for explaining reading of the optical diffraction pattern recording medium of FIG.

FIG. 3 is a diagram for explaining an example of signal processing for authentication of an optical diffraction pattern recording medium according to the present invention.

FIG. 4 is a cross-sectional view in the case where the optical diffraction pattern recording medium of the present invention is configured in the form of a transfer sheet.

FIG. 5 is a cross-sectional view when the optical diffraction pattern recording medium of the present invention is configured in a seal shape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin layer 2 Thin film layer 3 Relief layer 4 Concealment layer 5 Adhesive layer 6 Infrared light absorption printing 7 Base material 8 Printing part 9 Optical diffraction pattern recording medium 10, 11 Optical sensor 3'Information pattern 6'Printing pattern 12 AND circuit 15 Peelable support

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[Procedure amendment]

[Submission date] March 3, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03H 1/18 8106-2K G06K 19/06 19/10 G09F 3/02 W 7028-5G

Claims (8)

[Claims] 1. A printing section comprising at least a relief layer in which a light diffraction pattern is recorded as a concavo-convex pattern, a concealing layer which substantially transmits infrared light and does not transmit visible light, and an infrared light absorbing portion or a reflecting portion. An optical diffraction pattern recording medium, characterized in that: 2. The relief layer is formed on the surface of a resin layer on which a light diffraction pattern is recorded as an uneven pattern, or on the surface of a resin layer on which the uneven pattern is recorded, and a refractive index different from the refractive index of the resin layer. The optical diffraction pattern recording medium according to claim 1, which comprises a thin film layer having a light transmitting property and capable of transmitting visible light and infrared light. 3. The printing unit comprising an infrared light absorbing portion or a reflecting portion comprises an infrared light absorbing layer and an infrared light absorbing print located on the concealing layer side thereof. The optical diffraction pattern recording medium described. 4. The infrared ray absorbing layer or the printing section consisting of the reflecting section comprises an infrared ray absorbing layer and an infrared ray reflecting print positioned on the concealing layer side of the infrared ray absorbing layer. The optical diffraction pattern recording medium described. 5. The optical diffraction pattern recording medium according to claim 1, wherein a peelable support is provided on the relief layer side to form a transfer sheet. 6. The optical diffraction pattern recording medium according to claim 1, wherein a peelable support is provided on the printing portion side via an adhesive layer to form a seal. . 7. A printing section comprising at least a relief layer in which a light diffraction pattern is recorded as a concavo-convex pattern, a concealing layer which substantially transmits infrared light and does not transmit visible light, and an infrared light absorbing portion or a reflecting portion. In the authentication method of the optical diffraction pattern recording medium in which the layers are sequentially laminated, infrared light is illuminated through the relief layer and the masking layer, and the patterning is reflected by the printing unit, and the masking layer and the relief layer are again reflected. Characterized by detecting the light transmitted through the infrared detection device by an infrared light detection device, by reading the pattern of symbols, characters, codes, etc. recorded in the printing unit to identify the optical diffraction pattern recording medium. A method of authenticating a light diffraction pattern. 8. The visible light of a predetermined wavelength is illuminated on the relief layer, the pattern diffracted from the relief layer is detected by a visible light detection device, and the detection signal and the visible light detected by the infrared light detection device are detected. 7. The optical diffraction pattern authentication method according to claim 6, wherein the optical diffraction pattern recording medium is identified based on the detection signal detected by the photodetection device.