JP4304001B2 - Authenticator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a true / false determination object.
Specifically, the triangular prismatic prisms are arranged in parallel on the surface of the base material, and have an optical diffraction grating structure on one or both surfaces of the prism facing the space. In such a case, the present invention relates to an authenticity determination body characterized in that the appearance state of an authentication medium changes depending on the viewing direction.
Such authenticity verifiers are used for authenticity determination such as securities, stock certificates, gift certificates, gift vouchers, credit cards, prepaid cards, passports, ID cards and other cards, video software, PC software, etc. Used as a seal.
[0002]
[Prior art]
Traditionally, securities, stock certificates, gift certificates, gift certificates, etc., credit cards, prepaid cards, various cards such as passports and ID cards, video software, PC software, etc. Holograms have been used in many fields where functional addition is required because of their excellent design and the difficulty of forgery and alteration that cannot be duplicated even on a color copying machine.
However, in recent years, clever counterfeit products have appeared in holograms, and there are cases in which true / false determinations cannot be made at first glance, and there is a need for authenticity determination bodies that can be easily determined visually.
[0003]
Therefore, a medium having optical characteristics can be considered as an authenticity determination body that does not use a hologram. Although Patent Document 1 is an optical security article, it has a complicated structure, and a manufactured product is considered to be expensive.
Moreover, although patent document 2 is not a technique related to a authenticity determination body regarding the manufacturing technique of a light-diffusion sheet, the technique which can be referred to manufacture of the authenticity determination body of this invention is described.
[0004]
[Patent Document 1]
JP 10-508549 A [Patent Document 2]
JP-A-5-169015 [Patent Document 1]
[Problems to be solved by the invention]
Therefore, in the present invention, in order to complete an authenticity determination body having a simple configuration having an optical function, the inventors have conceived of using the optical characteristics of the light diffusion sheet of Patent Document 2 described above, and have completed the present invention. It is a thing.
[0006]
[Means for Solving the Problems]
The first of the gist of the present invention for solving the above problems is a true / false determination body used for an authentication medium, which is a minute triangular prism prism made of a transparent material that is substantially linear on the substrate surface. Are arranged in parallel, one surface of the triangular prismatic prism is in contact with the base material surface, and light diffraction is performed on a common surface on one side of the surface facing the space. The authenticity determination body is characterized in that a grating structure is formed and a light reflecting layer is provided on the surface of the optical diffraction grating structure .
[0007]
The second of the gist of the present invention for solving the above-mentioned problems is a true / false determination body used for an authentication medium, which is a minute triangular prism prism made of a transparent material that is substantially linear on the substrate surface. Are arranged in parallel, one surface of the triangular prismatic prism is in contact with the base material surface, and light diffraction is performed on a common surface on one side of the surface facing the space. The authenticity determination body is characterized in that the grating structure is formed periodically or at a certain probability frequency, and a light reflection layer is provided on the surface of the optical diffraction grating structure .
[0008]
The third of the gist of the present invention for solving the above problems is a true / false determination body used for an authentication medium, which is a minute triangular prism prism made of a transparent material that is substantially linear on the substrate surface. Are arranged in parallel, one surface of the triangular prism is in contact with the base material surface, and the light diffraction grating structure is formed on both surfaces facing the space. The authenticity determination body is characterized in that it is formed periodically or at a certain probability frequency, and a light reflection layer is provided on the surface of the optical diffraction grating structure .
[0009]
In the above, the height of the three prismatic prism, if it is from the substrate surface in the range of 5Myuemu～1000myuemu, can be suitably used as authenticity determination member.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an external perspective view showing an example of the authenticity determination body of the present invention, FIG. 2 is a view showing a cross section of a triangular prism that constitutes the authenticity determination body, and FIG. 3 shows the triangular prism of FIG. FIG. 4 is a diagram showing a state of observing, and FIG. 4 is a diagram showing a state of observing another triangular prism.
[0011]
As shown in FIG. 1, the authenticity determination body 1 of the present invention has a configuration in which minute triangular prisms 3 are arranged in parallel on the surface of a substrate 2.
The base material 2 has a substantially flat surface, and generally a plastic sheet material or a film base material is used. A pattern or the like may be printed on the prism surface 2a of the base material 2. However, in many cases, the lower surface side of the base material 2 is an authentication medium that is subject to authenticity determination. It is often possible to observe the design.
Therefore, although not shown, a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive or a rehumidity or hot-melt adhesive layer may be formed in contact with the lower surface side 2b of the substrate 2.
[0012]
The small triangular prism 3 is made of a transparent or colored transparent plastic material, one surface of which faces the base material 2 and the other two surfaces face the space. Here, “transparent” means transparency that allows the surface of the substrate 2a to be clearly seen through the triangular prism 3.
The triangular prisms may be arranged such that the ridge lines on the surface of the substrate 2 are in contact with each other, and may be arranged so as to have a certain flat area that does not exceed the prism pitch between the ridge lines.
[0013]
FIG. 2 is a view showing a cross section orthogonal to the length direction of the triangular prism 3 and corresponds to a partially enlarged cross section of the authenticity determination body of FIG. In the case of FIG. 2, the prism has a right-angled isosceles triangle, and a surface with respect to a right angle, that is, a slope 3c that is not equilateral, is in contact with the base material 2, and the other two surfaces 3a and 3b face the space. .
In this example, an optical diffraction grating structure 3d is formed on one side common surface 3a of each prism among the two surfaces facing the space. The other side surface 3b is transparent so that the pattern of the authentication medium can be observed. Although not shown, a light reflecting metal layer may be provided on the surface of the light diffraction grating structure 3d, and in this case, the light diffraction effect can be further enhanced.
In the case of FIG. 2, a sawtooth-shaped grating is shown as the optical diffraction grating structure 3d, but it may be rectangular.
[0014]
The height H from the base material surface 2a of the triangular prism 3 is preferably about 5 μm to 1000 μm. This is because the triangular prism 3 itself functions as a diffraction grating when the thickness is several μm or less, and it becomes difficult to make the inclined surface of the small triangular prism 3 with the optical diffraction grating structure 3d. The height H is not particularly limited, but if it is 1000 μm or more, the thickness will be too thick for a medium to be attached to the authentication medium.
[0015]
FIG. 3 is a diagram illustrating a state in which the triangular prism prism of FIG. 2 is observed, and FIG. 4 is a diagram illustrating a state in which another triangular prism is observed.
In the case of FIG. 3, the isosceles right triangular surface 3c is in contact with the base material 2, and the light diffraction grating structure 3d is formed on the common surface of the inclined surface 3a among the other two surfaces 3a and 3b sandwiching the right angle. ing.
In this state, when the authenticity determination body 1 is observed from the direction of the inclined surface 3a (direction A), only the diffracted light L from the optical diffraction grating structure 3d is visually recognized by the observer's eyes 5e. Appears as an object that changes color.
[0016]
On the other hand, since the inclined surface 3b is left as a transparent surface that has not been treated, it appears as a transparent body when observed from a direction (direction B) orthogonal to the surface 3b, and the base 2 of the authenticity determination body 2 When the printed material on the surface 2a or the base material 2 is transparent and the authentication medium 4 is present thereunder, the design of the authentication medium 4 can be observed.
[0017]
In the case of FIG. 4, among the two surfaces 3a and 3b sandwiching the right angle of the right isosceles triangle, the surface 3a is in contact with the substrate 2, and the optical diffraction grating structure 3d is formed on the inclined surface 3c. Therefore, the surface 3b on which the optical diffraction grating structure 3d is not formed is a surface perpendicular to the substrate 2.
In this state, when the authenticity determination body is observed from the A direction or the C direction, only the diffracted light L is visible to the observer's eyes 5e as in the case of FIG. The formed slope 3c appears as an object whose color changes depending on the viewing angle.
[0018]
On the other hand, when observing from the B direction, since light is transmitted, the pattern of the authentication medium 4 can be observed.
2, 3, and 4, right-angled isosceles triangles are illustrated, but the apex angle that sandwiches the isosceles is not limited to a right angle, and an arbitrary angle in the range of about 60 to 120 degrees. Can be adopted. It can be easily imagined that the same effect can be obtained even when the triangle does not have the same two sides.
[0019]
FIGS. 3 and 4 show an example (in the case of claim 1) in which the light diffraction structures 3d are formed on all of the common surfaces of the oblique sides facing the space. May be formed periodically, or may be formed with a certain probability frequency (for example, without considering periodicity such as three of the ten surfaces). good. Further, the present invention is not limited to any one surface, and may be formed periodically or at a certain probability frequency with a certain interval between both surfaces unless it is formed on the entire surface.
In the case of forming either one surface periodically or with a constant probability frequency, it is included in the invention of claim 2, and when forming both surfaces periodically or with a certain probability frequency, the method according to claim 3. It will be included in the invention.
In these cases, since periodicity and probability frequency can be characterized, forgery and alteration can be made more difficult.
[0021]
As described above, the authenticity determination body according to claim 1 of the present invention has a feature that the diffracted light can be seen and the transparent state are switched depending on the viewing direction of the observer.
Moreover, in the authenticity determination body of Claim 2 or Claim 3, diffracted light is observed with a fixed period and probability frequency.
The authenticity determination body having such a configuration requires an advanced manufacturing technique as described below, and has an advantage that it cannot be easily manufactured.
Therefore, it is considered that forgery and imitation can be effectively prevented by using such authenticity determination body as an authentication medium.
[0022]
Light diffraction occurs in a diffraction grating pitch range of about 1/4 to 2 times (several μm) of the wavelength of light, but is usually set to a grating pitch of about 1 to 3 μm, and the depth is less than 0. The thickness is about 2 to 0.5 μm.
It is not limited to a sawtooth grating, and may be a rectangular recess. Moreover, the shape seen from the plane is not limited to a linear lattice, and may be a curved shape. Hologram interference fringes may be used for the purpose of the present invention, but it is a very difficult technique to partially provide a hologram pattern on an uneven embossed narrow slope.
[0023]
The optical diffraction grating structure mold is formed by (1) a method of precisely cutting a soft metal with a diamond tip using a ruling engine, and (2) applying a photoresist to a glass plate to form a pattern, and then forming a plasma. For example, there is a method of forming a rectangular shape by etching and forming a conductive film for electrodeposition and then molding by electroforming.
As the former soft metal, phosphor bronze, oxygen-free copper, brass, or a material obtained by nickel plating on a carbide base material is used. For the purpose of the present invention, a copper material used for a gravure cylinder can be cut and used.
[0024]
Next, a method for manufacturing the authenticity determination body will be described.
FIG. 5 is a diagram showing an apparatus for manufacturing a triangular prism, and FIG. 6 is a diagram showing a process of forming a light reflection layer on the triangular prism.
The manufacturing process of the triangular prism prism other than the embossed type manufacturing of the optical diffraction grating structure can be performed using the apparatus of FIG. The manufacturing process by the apparatus includes a resin filling process, a contact process, a curing process, an adhesion process, and a peeling process with respect to the concave portion of the mold.
[0025]
In FIG. 5, 10 is a roll intaglio in which concave portions of triangular prisms are formed, 11 is a concave portion of the roll intaglio, 12 is a coating device for applying an ionizing radiation curable resin liquid to the roll intaglio 10, and 13 is An ionizing radiation curable resin liquid, 2 is a sheet base material, 14 is a solvent drying device, 15 and 16 are curing devices, 17 is a pressing roll that contacts the roll intaglio and presses the roll intaglio 10, and 18 is a feed roll. .
[0026]
Since one side surface of the triangular prism is the optical diffraction grating structure 3d, it is necessary that a fine diffraction grating surface be formed on the one side surface of the recess 11.
In FIG. 5, the recesses 11 for forming the triangular prisms are illustrated so as to be orthogonal to the flow direction of the sheet base material 2, but actually formed in parallel to the flow direction of the sheet base material 2. In the case where the diffraction grating surface is formed along the circumference of the rotating mold roll, it is considered that the production is easier.
[0027]
The filling step in the triangular prism manufacturing process is a step of rotating the roll intaglio 10 on which the triangular prism prism mold is formed, and filling the ionizing radiation curable resin liquid 13 into at least the recess 11 of the roll intaglio 10.
The contact step is a step of bringing the sheet base material 2 that travels in synchronization with the rotation direction of the roll intaglio 10 against the ionizing radiation curable resin liquid 13 filled in the filling step.
[0028]
In the curing step, the ionizing radiation from the curing device 15 is applied to the ionizing radiation curable resin liquid 13 between the roll intaglio 10 and the sheet base 2 while the sheet base 2 is in contact with the roll intaglio 10 in the contact step. Is a step of curing by irradiation.
The adhesion process is a process in which the ionizing radiation curable resin liquid 13 cured in the curing process and the sheet substrate 2 are adhered to each other. The curing process and the adhesion process usually proceed simultaneously. The peeling process is a process of peeling the semi-cured product 13a of the ionizing radiation curable resin liquid 13 and the sheet base material 2 which are adhered in the adhesion process from the roll intaglio 10.
[0029]
The roll intaglio 10 is a cylindrical plate material provided with a concave portion 11 having a predetermined shape.
The coating apparatus 12 is an apparatus for applying the ionizing radiation curable resin liquid 13 to the roll intaglio 10 and often uses a nozzle coating apparatus. In the nozzle coating apparatus, a nozzle having a predetermined size has a T-die-shaped rectangular or linear discharge port, the longitudinal direction of the discharge port is installed in a direction orthogonal to the roll intaglio rotation direction, The resin liquid is discharged only to a predetermined width portion of the entire width.
[0030]
The solvent drying device 14 is a device for volatilizing a resin solvent. As the solvent drying device 14, warm air, an infrared heater, or the like can be used. By providing this solvent drying device 14, a solvent-type resin can be used, and the range of selection of the resin to be used can be expanded. When the solventless ionizing radiation curable resin liquid 13 is used, the solvent drying device 14 is not used.
[0031]
The curing device 15 is a device that cures the ionizing radiation curable resin liquid 13 by irradiating with ionizing radiation. A curing device 16 may be provided in order to completely cure the semi-cured product 13a of the ionizing radiation curable resin liquid detached after the peeling step.
Here, the ionizing radiation means an electromagnetic wave or a charged particle beam having energy quanta capable of polymerizing and crosslinking molecules, and usually ultraviolet rays, electron beams and the like are used. In the case of ultraviolet rays as the curing devices 15 and 16, a light source such as an ultrahigh pressure mercury lamp, a black light lamp, a xenon lamp, or a metal halide lamp can be used.
[0032]
<Manufacture of triangular prisms>
In the manufacturing method of the prismatic prism by the above apparatus, first, the ion beam radiation curable resin liquid 13 is filled in the concave portion 11 of the roll intaglio 10 by the coating device 12, and the sheet base material 2 is filled in the concave portion 11 of the roll intaglio 10. The ionizing radiation curable resin liquid 13 is brought into contact with the liquid.
As a method of filling the concave portion 11 with the ionizing radiation curable resin liquid 13, a predetermined amount of the ionizing radiation curable resin liquid 13 is coated in advance on the surface of the roll intaglio 10, and the base sheet 2 is placed on the surface of the roll intaglio 10. when supplied to the, by the pressing of the pressing roll 1 7, through the substrate sheet, an ionizing radiation-curable resin liquid 13 which is applied to distributed filling in the recess 11.
[0033]
In this case, a solvent-type curable resin can be used, and the ionizing radiation curable resin liquid 13 applied to the sheet substrate 2 is used to dilute the solvent of the resin liquid in order to control the fluidity to some extent. The solvent and the like used in the above are dried and removed by the solvent drying device 14, and the resin liquid obtained by drying the solvent by the curing device 15 is semi-cured.
[0034]
While the sheet substrate 2 is in contact with the roll intaglio 10, the ionizing radiation curable resin liquid 13 is cured by the curing device 15. If necessary, a plurality of curing devices can be provided along the rotation direction of the roll intaglio. Curing of the cured product, curling of the sheet substrate 2 and the like can be reduced by multi-stage curing.
Alternatively, the roll intaglio 10 may be formed of a material having good ionizing radiation permeability, such as quartz or glass, and irradiated from the inside of the roll intaglio 10.
[0035]
The ionizing radiation curable resin liquid 13 in the recess 11 of the roll intaglio 10 is brought into close contact with the sheet substrate 2 by the curing device 15. At this time, the degree of curing may be such that at least the fluidity of the resin is lost and the adhesiveness with the sheet substrate 2 is caused.
After passing through the curing device 15, the sheet substrate 2 is peeled from the roll intaglio 10.
Thereby, the authenticity determination body sheet | seat which has the surface by which the semicured ionizing-radiation-curable resin liquid 13a was united with the sheet | seat base material 2, and was detach | desorbed from the recessed part 11, and was made into the prism is obtained.
[0036]
<Formation of light reflection layer>
The light reflection layer can be formed on one surface of the triangular prism by vacuum deposition, sputtering, ion plating, or the like.
FIG. 6 shows a process of forming a light reflection layer on a triangular prism, and shows a method by vacuum deposition. With respect to the prism surface having an angle of 45 degrees with respect to the sheet base material 2, the authenticity determination body 1 is inclined at 45 degrees with respect to the direction of scattering of the vapor deposition metal of the vapor deposition source 7 as shown in FIG. Thus, the light reflecting layer 3m can be formed by vapor deposition only on one side surface of the triangular prism.
For the formation of the light reflection layer, aluminum or other reflective metal material described later can be used as the vapor deposition material.
[0037]
<Embodiment related to material>
(1) The substrate substrate is not particularly limited, such as a polymer film, paper, metal, fabric, etc., but when transparency is required, a polymer film is preferable from the viewpoint of processability.
The plastics for the polymer film are polyethylene resin, polypropylene resin, polymethylpentene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin. , Ethylene-vinyl alcohol copolymer resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate-isophthalate copolymer resin, polymethyl methacrylate resin, polycarbonate resin, polyarylate resin, polyimide resin, polysulfone resin, acrylic resin, etc. Can be used. A liquid crystal material can also be used.
The thickness of the substrate is preferably in the range of about 12 to 200 μm from the viewpoint of ease of processing.
[0038]
The base material may be transparent or opaque, but when a transparent base material is used, it is combined with a medium on which information such as patterns and characters is displayed, and the information is visually recognized when transmitted. be able to. When the base material is opaque, it is not possible to visually recognize the design of the authentication medium under the base material, but by applying information such as a pattern, characters, etc. on the base material surface by a method such as printing, these Information can be visually recognized.
[0039]
(2) Triangular prismatic prism body The material of the prism body is not particularly limited, but a resin material is preferable from the viewpoint of suitability for processing. Moreover, it is calculated | required that it is transparent or colored transparent from a prism characteristic.
In the above-described manufacturing method for forming a prism shape with an ultraviolet curable resin, an ultraviolet curable ionizing radiation curable resin liquid is preferably used.
As a specific example of such a resin liquid, a composition in which prepolymers, oligomers and / or monomers having a polymerizable unsaturated bond or an epoxy group in the molecule are appropriately mixed can be used.
[0040]
Examples of the prepolymer and oligomer include unsaturated polyesters such as a condensate of unsaturated dicarboxylic acid and multi-valued alcohol, epoxy resins, polyester methacrylate, polyether methacrylate, polyol methacrylate, methacrylates such as melamine methacrylate, polyester acrylate, epoxy Examples include acrylates such as acrylate, urethane acrylate, polyether acrylate, polyol acrylate, and melamine acrylate.
[0041]
Examples of the monomer include styrene monomers such as styrene and α-methylstyrene, acrylic acid esters such as methyl acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, and butyl acrylate, and methacrylic acid. Methacrylates such as methyl acetate, ethyl methacrylate, methoxyethyl methacrylate, methoxymethyl methacrylate, unsaturated substituted amino alcohol esters such as acrylic acid-2- (N, N-diethylamino) ethyl, acrylamide, methacryl Unsaturated carboxylic acid amides such as amides, polyfunctional compounds such as dipropylene glycol diacrylate, ethylene glycol acrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate, vinyl pyrrolidone, and / or molecules Polythiol compounds having two or more thiol groups, such as trimethylolpropane trithioglycolate, trimethylolpropane tri thio propylate, pentaerythritol thioglycolate and the like.
[0042]
In particular, in the case of curing by ultraviolet rays, as a photopolymerization initiator in the composition of the ionizing radiation curable resin, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylmeurum monosulfide, As a thioxanthone and / or a photosensitizer, n-butylamine, triethylamine, tri-n-butylphosphine, or the like can be mixed and used. Further, in order to faithfully reproduce the shape of the roll intaglio 10 having the fine concave portion 11 of the prism, the viscosity is preferably 5000 cps or less, particularly 1000 cps or less. When the prism is colored and transparent, a dye that does not inhibit curing may be added.
[0043]
(3) Light reflecting layer The materials used for forming the light reflecting layer are aluminum (Al), zinc (Zn), indium (In), gold (Au), silver (Ag), cobalt (Co), tin (Sn). ), Selenium (Se), titanium (Ti), iron (Fe), tellurium (Te), copper (Cu), lead (Pb), nickel (Ni), palladium (Pd), etc., or their alloys Can be used.
[0044]
【Example】
An embodiment of the present invention will be described with reference to FIGS. 2, 3, 5, and 6.
(Manufacture of embossed roll intaglio)
Using a gravure roll having a circumference of 500 mm, an embossing roll intaglio having an optical diffraction grating mold was produced.
First, silver plating was applied to a thin layer on a gravure iron core roll, and then a ballad copper layer was plated to a thickness of 500 μm. After smooth polishing of the copper layer surface, a diamond cutter was used to continuously cut a concave groove having a right-angled triangle with a depth of 200 μm along the circumference while rotating the roll.
At this time, the interval pitch between one groove and the adjacent groove is calculated to be 400 μm, but the space pitch is set to 420 μm so that a flat portion of 20 μm remains between the adjacent grooves.
[0045]
Next, a sawtooth diffraction grating having a depth of 0.5 μm with respect to the inclined surface and a pitch of 2 μm on the inclined surface was cut circumferentially with a diamond cutter on the common inclined surface of the concave groove. Note that 120 diffraction gratings were cut on one inclined surface.
Every time one diffraction grating was cut, the cutting position (horizontal direction) and the height of the cutter blade were shifted by 1.4 μm, so precise numerical control management was performed.
Finally, chrome plating was applied to the entire surface including the optical diffraction grating cut surface to a thickness of 4 μm and the surface was polished to complete the embossing roll intaglio 10.
[0046]
Example 1
Using the embossing roll intaglio prepared above, the authenticity determination body 1 was manufactured using the manufacturing apparatus of FIG.
By a method of curing a urethane acrylate-based ultraviolet curable resin liquid 13 on a polyethylene terephthalate film (PET) substrate 2 having a thickness of 100 μm, as shown in FIG. 2, an isosceles right angle with a height of 200 μm and an apex angle of 90 degrees. A triangular prism 3 was formed. Since the 3a surface of the triangular prism 3 is based on the diffraction grating of the embossing roll intaglio, an optical diffraction grating structure 3d having a pitch of 2 μm and a depth of 0.5 μm is formed.
When this true / false judgment object 1 was observed from the A direction shown in FIG. 3, it could be seen as an object whose color changes depending on the viewing angle, and when observed from the B direction, it could be visually recognized as a transparent film.
[0047]
(Example 2)
The authenticity determination body 1 manufactured in Example 1 is disposed with a base material 2 inclined at 45 degrees with respect to the vapor deposition source 7, and aluminum (Al) metal is vapor-deposited. The authenticity determination body 1 in which the light reflection layer 3m was formed only on one side formed was obtained (FIG. 6).
When this true / false judgment object 1 was observed from the A direction shown in FIG. 3, it could be seen as an object whose color changes depending on the viewing angle, and when observed from the B direction, it could be visually recognized as a transparent film. The light diffraction effect of this authenticity determination body was stronger than that of Example 1.
[0048]
【The invention's effect】
As described above, according to the authenticity determination body of the present invention, the following effects can be obtained.
The authenticity determination body (Claim 1 ) of the present invention switches the surface having the optical diffraction grating structure and the transparent surface where the authentication medium or the like can be visually recognized depending on the viewing direction. In contrast, authenticity can be determined immediately.
Since the surface having the optical diffraction grating structure appears periodically or at a certain probability frequency, the authenticity determination body of the present invention (Claim 2, Claim 3 ) is an article that does not involve such a state change. In contrast, authenticity can be determined immediately.
Further, the authentication medium or the like with the authenticity determination body stuck cannot be copied normally with a copying machine, and forgery and imitation can be prevented.
Since the manufacture of the authenticity determination body of the present invention is relatively difficult, it is difficult to obtain, and forgery and counterfeiting can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is an external perspective view showing an example of a true / false determination object according to the present invention.
FIG. 2 is a diagram showing a cross section of a triangular prism that constitutes an authenticity determination body.
FIG. 3 is a diagram showing a situation in which the triangular prism prism of FIG. 2 is observed.
FIG. 4 is a diagram showing a situation where another triangular prism is observed.
FIG. 5 is a diagram showing an apparatus for manufacturing a triangular prism.
FIG. 6 is a diagram illustrating a process of forming a light reflection layer on a triangular prism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Authenticity determination body 2 Base material, sheet base material 3 Triangular prism 3d Light diffraction grating structure 3m Light reflection layer 4 Authentication medium 5e Human eyes 7 Deposition source 10 Roll intaglio 11 Recess 12 Coating device 13 Ionizing radiation curable Resin liquid 14 Solvent dryers 15 and 16 Curing device 17 Press roll 18 Feed roll

Claims (3)

A true / false determining body used for an authentication medium, wherein the triangular shape is formed by arranging in parallel micro triangular prisms made of a transparent material that is substantially linear on a substrate surface. one surface of the columnar prisms are in contact with the substrate surface, the common face of either side of the surface facing the space, optical grating structure is formed, on the surface of the diffraction grating structure A true / false determining body provided with a light reflecting layer . A true / false determining body used for an authentication medium, wherein the triangular shape is formed by arranging in parallel micro triangular prisms made of a transparent material that is substantially linear on a substrate surface. One surface of the columnar prism is in contact with the base material surface, and the optical diffraction grating structure is formed periodically or at a certain probability frequency on the common surface on either side of the surface facing the space , An authenticity determination body , wherein a light reflection layer is provided on a surface of the optical diffraction grating structure . A true / false determining body used for an authentication medium, wherein the triangular shape is formed by arranging in parallel micro triangular prisms made of a transparent material that is substantially linear on a substrate surface. one surface of the columnar prisms are in contact with the substrate surface, the both surfaces of the surface facing the space, optical grating structure is formed by periodically or certain probability frequency, said diffraction grating A true / false determining body characterized in that a light reflecting layer is provided on the surface of the structure .

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