JP2012173464A - Production method for image forming body, image forming body, and personal authentication medium - Google Patents

Abstract

A method of manufacturing an image forming body that displays an image of high quality image quality and is difficult to tamper with, and a personal authentication medium obtained by transferring the image forming body.
An image forming body having a plurality of gradations including an owner information display unit that displays information relating to an owner as an image so as to be visible is used for each image cell using two or more thermal hologram ribbons having different diffraction efficiencies. The recording area is changed and recorded.
[Selection] Figure 9

Description

  The present invention relates to an image forming body that prints, prints, and draws a face image and a fingerprint, which are essential to individual identification, on a booklet such as a passport or a visa or a personal authentication medium such as a card, and in particular, an authentic owner. Personal identification information such as the face of a person can be easily formed by combining a diffraction grating or a structure with irregularities in the shape of a diffraction grating and on-demand printing technology, and an examiner who performs personal authentication can identify The present invention relates to a method of manufacturing an image forming body, an image forming body, and a personal authentication medium that are easy to be counterfeited and difficult to forge and tamper.

  Many personal authentication media such as passports and ID (identification) cards use facial images in order to enable visual personal authentication. For example, in a passport, conventionally, photographic paper on which a face image is printed is pasted on a booklet. However, such passports may be tampered with by reprinting photographic prints.

  For these reasons, in recent years, there is a tendency to digitize facial image information and reproduce it on a booklet. As this image reproduction method, sublimation (heat transferable) dyes, thermal transfer recording methods using transfer ribbons using resin-type melting type or wax-melting type in which pigments are dispersed, or electrophotography are being studied. Yes.

  In addition to the above method, the image reproduction method to the passport includes a recording method using an ink jet printer (for example, see Patent Document 1), a laser printing recording method using a CO2 or YAG laser and a thermal color former (for example, Patent Document 2). Further, there is a laser engraving print recording method (for example, see Patent Document 3) in which carbon (C) present in the base material is used for printing and recording in the depth direction of the base material.

  Further, as an image display body containing this kind of personal recognition data, an image pattern formed based on the image data is provided on a card substrate such as polyvinyl chloride, or a hologram in addition to the image pattern. And those having so-called OVD (Optical Variable Device) images represented by images by using optical thin films using diffraction gratings or multilayer interference (effects such as color shift can be obtained by optical design) are known. ing.

  These OVD techniques for holograms and diffraction gratings require advanced manufacturing techniques and are difficult to duplicate, and thus have been used for cards such as credit cards, ID cards, and prepaid cards as effective forgery prevention means. Furthermore, due to its high decorativeness, it is often used for packaging materials, books, pamphlets, POPs, and the like. As a means for adhering these OVDs to articles, a method of transferring and forming using a transfer foil has been conventionally employed. This type of transfer has a structure in which a release layer, a relief layer for forming an image pattern of a hologram or diffraction grating, a reflective layer formed by a known thin film forming means, and an adhesive layer are sequentially bonded on a support. It has been known. These OVD patterns (holograms and diffraction grating patterns) engraved on the transfer foil are replicated in large quantities by a well-known method in which a minute uneven pattern is duplicated on a nickel-based press plate and heated and pressed on a relief layer.

In addition, the reflective layer can be formed as a transparent hologram or a transparent diffraction grating by forming a transparent material having a different refractive index by a known thin film forming means such as a vacuum deposition method (hereinafter referred to as a transparent thin film layer). This is a known technique. In this case, it is clear from an optical point of view that the greater the difference in refractive index between the relief layer and the transparent thin film layer, the greater the reflectance. However, here in general,
(Refractive index of relief layer) <(Refractive index of transparent thin film layer)
There is a relationship.

  The hologram or diffraction grating structure thus obtained is used as a means for preventing counterfeiting, such as credit cards, cash cards, membership cards, employee cards, prepaid cards, driver's licenses, gift cards, gift certificates, etc. In addition to various paper certificates such as stock certificates, various forms such as application forms, receipts, and copy slips, various booklets such as passports, passbooks, and pension notebooks, displays such as covers and panels such as books and notebooks, etc. It is used by sticking to a part or the whole. In addition, the whole described in the present invention has a conceptual meaning, regardless of a pattern, a pattern, or the like, a spot shape, a stripe shape, a thing stuck on a lattice, a regular shape, an irregular shape halftone dot Also included are those stuck with dots in the shape of a circle.

  Such an OVD transfer foil performs a sufficient function as an anti-counterfeiting effect, but is formed by thermally transferring an OVD transfer layer on the image after forming an image such as a face photograph like a passport. At present, when the forgery technology has been developed, there is a possibility that the transfer layer is once removed by some method, the image data or the like is altered, and then the OVD transfer foil is placed again.

  In addition, there is a possibility that image data may be falsified by selecting a person whose face shape / atmosphere is similar to the face photo of an authentication medium such as a stolen passport and pasting the printed photo over the face. .

  In addition, in consideration of the situation in which the sublimation transfer method, the heat-melting transfer ribbon method, or the electrophotographic method, as a means for forming image information such as a facial photograph, is now widely used, an image forming unit It is becoming difficult to say that it is always difficult to form a new image in the area after removing the image.

  In order to solve the above problems, a method of putting a plurality of pieces of information for identifying an individual such as a face photograph is considered. As one of the methods, a direct thermal transfer method using a hologram ribbon, in which image information such as a face photograph is formed by a hologram or a diffraction grating, is known (see, for example, Patent Document 4). As a result, the holographic image must be altered simultaneously with the alteration of the face photograph or the like by the color image, so that the alteration can be made more difficult.

JP 2002-226740 A JP 49-131142 A JP 2006-123174 A JP 10-049647 A

  However, image formation by direct thermal transfer using a hologram ribbon is difficult to form a fine image, and the hologram ribbon is inferior in temperature detection performance compared to an ink ribbon. It is very difficult to express an image with gradation using it.

  The present invention has been made in view of the above-mentioned problems of the prior art, and forgery or falsification of an image forming body that requires high security, such as a passport, a visa, or various cards. Alternatively, a method for producing a high-quality image forming body capable of easily discovering a suspicious product by observation or the like, even in the event of fraud, preventing performance against alteration, and image formation thereof An object of the present invention is to provide a personal authentication medium obtained by transferring a body.

The invention according to claim 1, which has been made in order to solve the above-described problem, includes an owner information display unit that displays information relating to the owner as an image on at least one surface of the transparent substrate so as to be visible. A method for producing an image forming body, comprising:
The owner information display unit includes a plurality of image cells formed in a dot shape,
The plurality of image cells include an OVD layer that forms an image of information about the owner, a reflective layer and an adhesive layer that are stacked on the OVD layer,
The OVD layer is provided by thermally transferring two or more thermal hologram ribbons having different diffraction efficiencies,
The thermal hologram ribbon is formed from fine irregularities of a hologram or a diffraction grating,
The image forming body is at least,
(1) A thermal hologram ribbon manufacturing step in which two or more thermal hologram ribbons having different diffraction efficiencies are arranged in a specific cycle in the thermal transfer flow direction;
(2) an image reading process for reading an image with gradation;
(3) a step of recording two or more thermal hologram ribbons according to the gradation of the image with the gradation, changing the printing area for each image cell;
It is produced through the process including this, The manufacturing method of the image forming body characterized by the above-mentioned.

  According to a second aspect of the present invention, in the manufacturing step (3) of the image forming body, the image with the gradation is divided into a plurality of layers according to the gradation, and the same number of different diffraction efficiencies as the number of the divided layers. A thermal hologram ribbon having a diffraction efficiency corresponding to each layer is produced by changing the print area for each image cell and expressing the gradation in each layer. The method of manufacturing an image forming body according to claim 1.

  The invention according to claim 3 is the method of manufacturing an image forming body according to claim 1 or 2, wherein the diffraction efficiency of the thermal hologram ribbon is controlled by the depth of fine irregularities.

  The invention according to claim 4 is characterized in that the diffraction efficiency of the thermosensitive hologram ribbon is controlled by the thickness of the reflective layer laminated on the OVD layer. Is the method.

  The invention according to claim 5 is an image forming body produced by using the manufacturing method according to claim 3 or 4.

  The invention according to claim 6 includes an owner information printing unit that prints an image having the same appearance as the image displayed on the owner information display unit, and the owner information display unit and the owner information printing unit are the same. The image forming body according to claim 5, wherein the image forming body is visible from the direction of the image.

  The invention according to claim 7 is that the area of the image printed on the owner information print layer is within a range of 0.1 to 30 times the area of the image displayed on the owner information display unit. The image forming body according to claim 6.

  The invention according to an eighth aspect is a personal authentication medium formed by transferring the image forming body according to any one of the fifth to seventh aspects to a substrate to be transferred.

  The invention according to claim 9 is characterized in that a striated pattern, which is a combination of thin lines, is printed in advance on the surface of the substrate to which the image is to be transferred. The personal authentication medium described.

  According to the invention described in claims 1 to 5, it is possible to provide an image forming body having individual information regarding the owner, which is formed from holograms or diffraction grating-like fine irregularities. In addition to this, it becomes difficult to form an image of individual information by forgery or the like, so that security can be improved. In addition, by forming images with multiple gradations using two or more types of thermal hologram ribbons with different diffraction efficiencies, it is possible to produce high-quality images that were difficult to express with printing using conventional hologram ribbons. It becomes possible to form.

  According to the invention described in claim 6, the person who owns the image forming body is displayed by the owner information printing layer to the examiner who identifies whether or not it is the true owner of the image forming body. And the image displayed on the owner information display section are selected from the personal authentication information of the same person. For this reason, by visually comparing the two images, it is possible to easily confirm the identity, and it is possible to exhibit easy-to-find performance that makes it possible to easily find the suspected fraudulent product.

  According to the invention described in claim 7, the area of the image of the owner information printing layer described in claim 5 is 0.1 to 30 times the area of the image displayed on the owner information display unit. By setting the area, the area of each image can be changed according to the application. For this reason, it becomes possible to easily compare and authenticate two images according to the application.

  According to the invention described in claim 8, it is possible to provide a personal authentication medium having individual information regarding the owner, which is formed from holograms or diffraction grating-like fine irregularities.

  According to the ninth aspect of the present invention, it is possible to obtain a personal authentication medium that is more difficult to counterfeit by printing in advance a coloring pattern for preventing counterfeiting on the surface of the substrate to which the image forming body is transferred. It becomes possible to provide. This is not the intermediate transfer method that is the process of the present invention, but the counterfeit is transferred directly to the owner-related pattern formed from holograms or diffraction grating-like fine irregularities on the transferred substrate side. The effect of the unevenness of the substrate to be transferred appears, so it is necessary to remove the unevenness before transfer.However, by performing the process of printing the anti-counterfeit color pattern in advance, The appearance of the pattern is different from the regular product, and it is possible to easily determine that the pattern is a counterfeit product.

1 is a plan view schematically showing a personal authentication medium according to an embodiment of the present invention. The top view which expands and shows a part of image information display part in the personal authentication medium shown in FIG. Sectional drawing along the II line of the image information display part shown in FIG. The top view which expands and shows other one part of the image information display part shown in FIG. Sectional drawing along the II-II line of the image information display part shown in FIG. FIG. 6 is a plan view schematically showing an example of a thermal hologram ribbon that can be used for manufacturing the image information display section shown in FIGS. 1 to 5. Sectional drawing which shows schematically an example of the thermal hologram ribbon shown in FIG. Sectional drawing which shows schematically another example of the thermosensitive hologram ribbon shown in FIG. Sectional drawing which shows schematically an example of the image forming body which can be manufactured using the thermal hologram ribbon shown in FIG. 6 thru | or FIG. Sectional drawing which expands and shows a part of image information display part in the personal authentication medium which concerns on a modification. Schematic which showed an example of the process of manufacturing the image forming body in this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same referential mark is attached | subjected to the component which exhibits the same or similar function through all the drawings, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a plan view schematically showing a personal authentication medium according to an embodiment of the present invention.

  A personal authentication medium 100 shown in FIG. 1 is a booklet such as a passport, and shows an open state.

  In FIG. 1, the personal authentication medium 100 includes an owner information display unit 1 and an owner information printing unit 2. The owner information display unit 1 is an image displayed by a hologram and / or a diffraction grating. As will be described in detail later, the owner information display unit 1 is formed by performing, for example, thermal transfer recording using a thermal head and thermal transfer recording using a hot stamp or a thermal roll in this order.

  The owner information printing unit 2 is an image displayed on the owner information display unit 1, that is, an image having the same appearance as that of the owner's face using light absorption. Specifically, the image is visible when illuminated with white light and observed with the naked eye.

  The owner information printing unit 2 can be composed of, for example, a dye and a pigment. In this case, the owner information printing unit 2 can be formed by a thermal transfer recording method using a thermal head, an ink jet recording method, an electrophotographic method, or a combination of two or more thereof. Alternatively, the owner information printing unit 2 can be formed by forming a layer containing a thermal color former and drawing on this layer with a laser beam. A combination of these methods can also be used. At least a part of the owner information printing unit 2 may be formed by a thermal transfer recording method using a hot stamp, a printing method, or a combination thereof.

  The owner information display unit 1 and the owner information printing unit 2 include face images of the same person, and the area of the image of the owner information printing unit 2 is relative to the area of the image displayed on the owner information display unit 1. And is set within a range of 0.1 to 30 times.

  This is due to the reason described below.

  For example, if the image printed on the owner information printing unit 2 has the same appearance as the owner's face photo (hereinafter referred to as “printed face photo image”) is a color face photo, The resolution of a photographic image is generally expressed by a halftone dot of 175 [lines / inch]. This is because even if the resolution is generally smaller than a halftone dot of 175 [lines / inch], it cannot be judged visually.

  On the other hand, the plurality of image cells 12a, 12a ′, 12b, 12b ′ constituting the image displayed on the owner information display unit 1 (hereinafter referred to as “displayed face photo image”) has a minimum of 5 μm. A circle or square size is required. When the face photograph of the owner is formed by the minimum size image cells 12a, 12a ′, 12b, and 12b ′, 1/30 of the size of the printed face photograph having a resolution of 175 [lines / inch]. A display face photographic image having a size can be obtained.

  In the case of a display face photograph image having a size of 1/30, it cannot be compared with a printed face photograph image unless viewed with a magnifying glass or the like. In this case, the size of the image cells 12a, 12a ′, 12b, and 12b ′ necessary for constructing the printed face photographic image becomes too small, and a sufficient function as a diffraction grating cannot be obtained.

  Further, even if the image cells 12a, 12a ′, 12b, and 12b ′ having the minimum size (5 μm) functioning as a diffraction grating are used, an image having the same number of pixels as the printed face photo image cannot be expressed. Image comparison between the printed face photo image and the displayed face photo image becomes difficult.

  On the other hand, if the displayed face photo image exceeds 10 times the size of the printed face photo image, the personal authentication information that is the owner's information cannot be accurately reproduced because it is too large. Image comparison between the image and the displayed face photograph image becomes difficult. Therefore, the ratio of the printed face photo image to the display face photo image is in the range of 0.1: 1 to 30: 1. This is because, as described above, if there is a ratio difference outside the range, it becomes difficult to compare the printed face photograph image and the display face photograph image, and the accuracy of personal identification is reduced. It should be noted that the size of the printed face photo image and the display face photo image may be enlarged / reduced at the same aspect ratio.

  Next, the structure of the personal authentication medium 100 will be described with reference to FIGS.

  FIG. 2 is an enlarged plan view showing a part of the owner information display unit 1 in the personal authentication medium 100 shown in FIG. 3 is a cross-sectional view taken along line II of the owner information display unit 1 shown in FIG. FIG. 4 is an enlarged plan view showing another part of the owner information display unit 1 shown in FIG. FIG. 5 is a sectional view taken along line II-II of the owner information display unit 1 shown in FIG.

  Image cells 12a, 12a ', 12b, 12b' contain holograms and / or diffracted light. The image cells 12a, 12a ', 12b, and 12b' have a pattern shape corresponding to the owner information display unit 1, as shown in FIGS. The structure and forming method of the image cells 12a, 12a ', 12b, 12b' will be described in detail later.

  The peel protection layer 13 covers the image cells 12 a, 12 a ′, 12 b, 12 b ′ and the substrate 11. The peeling protective layer 13 has light transmittance and is typically transparent. The peeling protection layer 13 is made of, for example, a resin.

  Next, the manufacturing method of the personal authentication medium 100 and the structure of the image cells 12a, 12a ', 12b, 12b' will be described with reference to FIGS.

  FIG. 6 is a plan view schematically showing an example of a hologram ribbon that can be used for manufacturing the image information display unit shown in FIGS. FIG. 7 is a cross-sectional view schematically showing an example of the hologram ribbon shown in FIG. FIG. 8 is a cross-sectional view schematically showing another example of the hologram ribbon shown in FIG. FIG. 9 is a cross-sectional view schematically showing an example of an image forming body that can be manufactured using the hologram ribbon shown in FIGS.

  The thermal hologram ribbon 200 shown in FIGS. 6 to 8 is, for example, a transfer ribbon. The thermal hologram ribbon 200 includes a support 21 and a transfer material layer 210 that is releasably supported by the support 21.

  The support 21 is a resin film or a sheet, for example. The support 21 is made of a material having excellent heat resistance such as polyethylene terephthalate. On the main surface of the support 21 that supports the transfer material layer 210, a release layer containing, for example, a fluororesin or a silicon resin may be provided.

  The transfer material layer 210 includes a release layer 27, a fine unevenness forming layer 24, a reflective layer 25, and an adhesive layer 26.

  The release layer 27 is formed on the support 21. The release layer 27 serves to stabilize the release of the transfer material layer 210 from the support 21 and promote adhesion of the image cells 12a, 12a ', 12b, and 12b' to the base material 11. The release layer 27 has light transmittance and is typically transparent. The release layer 27 is made of, for example, a thermoplastic resin, but can be omitted.

  The fine unevenness forming layer 24 is formed on the release layer 27. The fine unevenness forming layer 24 includes at least one of a hologram and a diffraction grating as a diffraction structure. Here, the fine unevenness forming layer 24 is a transparent layer having a relief structure as a diffraction structure on the surface. Moreover, as a material of the transparent layer, a resin such as a photo-curing resin, a thermosetting resin, and a heat-sparse resin can be used.

As a parameter of the diffraction structure of the fine unevenness forming layer 24,
(1) Spatial frequency of diffraction grating (pitch of grating line: number of grating lines per unit length)
(2) Direction of diffraction grating (direction of grating line)
(3) There is a depth of the diffraction grating, and according to the above (1), the color at which the diffraction grating pattern appears shining with respect to the fixed point changes,
In accordance with (2) above, the direction in which the diffraction grating cell appears shining changes,
In accordance with (3) above, the light intensity (diffraction efficiency) when the diffraction grating pattern appears to shine changes.

  In the hologram ribbon of the present invention, for example, as shown in FIG. 7, the fine unevenness forming portions H1 and H1 ′ in which (1) and (2) are the same and only (3) is changed, The fine concavo-convex formation part H2 in which only (1) is changed, and H2 are composed of a fine concavo-convex formation layer in which fine concavo-convex formation parts H2 ′ in which only (3) is changed are arranged in order. At this time, a gradation of a color that can be seen at a fixed point is obtained by the fine unevenness forming portions H1 and H1 ′, and a gradation of a color different from the fine unevenness forming portion H1 that is visible at a fixed point is expressed by the fine unevenness forming portions H2 and H2 ′. It becomes possible to do. H1 and H2 are fine concavo-convex forming portions with high diffraction efficiency, and H1 ′ and H2 ′ are fine concavo-convex forming portions with low diffraction efficiency.

  As will be described later, since the image cells formed by the plurality of fine unevenness forming portions are transferred in the form of dots, a plurality of gradations can be expressed by changing the dot diameter of the image cells to be transferred. Further, if a fine unevenness forming part having a spatial frequency different from that of the fine unevenness forming parts H1 and H2 is provided, for example, if the color appearance at a fixed point is three colors of R, G, and B, a full color It is also possible to obtain a multi-tone image.

  The reflective layer 25 is formed on the fine unevenness forming layer 24. Although the reflection layer 25 can be omitted, the visibility of the image displayed by the diffraction structure is improved by providing the reflection layer.

  As the reflection layer 25, for example, a transparent reflection layer or an opaque metal reflection layer can be used. The reflective layer 25 can be formed by, for example, a vacuum film forming method such as vacuum deposition or sputtering.

As the transparent reflective layer, for example, a layer made of a transparent material having a refractive index different from that of the fine unevenness forming layer 24 can be used. The transparent reflective layer made of a transparent material may have a single layer structure or a multilayer structure. In the latter case, the transparent reflection layer may be designed so as to repeatedly cause reflection interference. As this transparent material, for example, a transparent dielectric such as ZnS and TiO ₂ can be used.

  Alternatively, a metal layer having a thickness of less than 20 nm may be used as the transparent reflective layer. As a material of the metal layer, for example, a metal layer such as chromium, nickel, aluminum, iron, titanium, silver, gold, and copper can be used.

  For example, as shown in FIG. 8, the hologram ribbon in the present invention includes a fine unevenness forming layer composed of two kinds of fine unevenness forming portions H <b> 1 and H <b> 2 having different spatial frequencies. In FIG. 8, a reflective layer 25 and a reflective layer 25 'having the same film forming material and different film thickness are provided on the back surfaces of the fine unevenness forming portions H1 and H2. The luminance of the image cells 12a, 12a ', 12b, 12b' can be changed by the thickness of the reflective layer. For example, when ZnS is used as the reflective layer, there is a large difference in the emission luminance of the image cell between a film thickness of about 10 nm and a film thickness of about 50 nm. In this way, by adjusting the film thickness of the film forming material, it is possible to express gradation when viewed at a fixed point.

  Further, similarly to the case described with reference to FIG. 7, a fine unevenness forming portion having a spatial frequency different from that of the fine unevenness forming portions H1 and H2 is provided, and the appearance at a fixed point is, for example, C, M, or Y By using three colors, it is possible to obtain a full-color multi-tone image.

  In manufacturing the personal authentication medium 100, for example, first, a person's face is photographed using an imaging device. Alternatively, a face image is read from the print. Thereby, image information is obtained as electronic information. This face image is image-processed with gradation.

  Next, a stacked body 310 shown in FIG. 9 is prepared. The laminated body 310 is a layer having a multilayer structure, and includes a support 31 and a peeling protection layer 33 and a resin layer 38 sequentially formed thereon. The multilayer structure formed on the support 31 constitutes an underlayer. The support 31 supports the base layer in a peelable manner.

  As the said support body 31, what was illustrated about the support body 21 of FIG. 7, for example can be used.

  The peeling protection layer 33 stabilizes peeling of the transfer material layer 210 composed of the peeling protection layer 33 and the image cells 12a, 12a ′, 12b, and 12b ′ from the support 21, and the image cells 12a, 12a ′, and 12b. , 12b 'is protected from damage. As the peeling protective layer 33, for example, those exemplified for the peeling layer 27 can be used. When the resin layer 38 has a state of a release layer, the release protective layer 33 can be omitted.

  The resin layer 38 has optical transparency and is typically transparent. The resin layer 38 has a role of giving sufficient strength to the previous base layer. As a material of the resin layer 38, for example, a thermosetting resin, a photocurable resin, and a thermoplastic resin can be used. When a thermosetting resin is used, the resin layer 38 can be used as an adhesive layer for bonding the image forming body 300 to the substrate 11.

  The resin layer 38 may include at least one of a hologram and a diffraction grating as a diffraction structure. For example, a relief structure as a diffractive structure may be provided on the surface of the resin layer 38. Thus, the image displayed by the diffraction structure and the image displayed by the image cells 12a, 12a ', 12b, 12b' can be overlapped or arranged.

  The laminated body 310 may further include a patterned metal reflection layer, for example, an opaque metal reflection layer. For example, a patterned metal reflection layer is provided on the resin layer 38 or between the peeling protection layer 33 and the resin layer 38, and halftone dots, lines, other figures, or combinations thereof are provided on the metal reflection layer. It may be displayed. Such a pattern can be used for authenticity determination of the image forming body 300 or the personal authentication medium 100, for example.

  Next, image cells 12 a, 12 a ′, 12 b, 12 b ′ having a pattern corresponding to the previous face image are formed on the laminate 310. Specifically, based on the previous image information, a part of the transfer material layer 210 is formed as image cells 12a, 12a ′, 12b, and 12b ′ from the support 21 shown in FIGS. 7 and 8, and the resin shown in FIG. Thermal transfer onto layer 38. The image cells 12 a, 12 a ′, 12 b, 12 b ′ include an adhesive layer 36, a reflective layer 35, a fine unevenness forming layer 34, and a release layer 37.

  The thermal transfer is performed using a thermal head so that the portion of the transfer material layer 210 that is thermally transferred onto the resin layer 38 has a pattern corresponding to the previous face image. As a result, an image forming body 300 including the support 31, the peeling protection layer 33, the resin layer 38, and the image cells 12a, 12a ', 12b, 12b' is obtained. The image forming body 300 is, for example, a transfer ribbon.

  Since the image cells 12a, 12a ′, 12b, and 12b ′ thus obtained are formed by thermal transfer using a thermal head, typically, the image cells 12a, 12a ′, 12b, and 12b ′ are composed of a plurality of dot-like portions as shown in FIGS. . Each center of these dot-like portions is located on a lattice point of a virtual planar lattice indicated by a broken line in FIGS.

  2 and 4, the previous planar lattice is a square lattice, but the planar lattice may be other lattices such as a triangular lattice and a rectangular lattice. Moreover, in FIG.2 and FIG.4, the adjacent dot-shaped part is arrange | positioned so that those outlines may contact | connect at one point. That is, the diameter of each dot-like part is equal to the minimum center-to-center distance of the dot-like part. Adjacent dot-like portions may be separated from each other. That is, the diameter of each dot-shaped portion may be smaller than the minimum center-to-center distance of the dot-shaped portion. Alternatively, the adjacent dot-like portions may be arranged so as to partially overlap. That is, the diameter of each dot-shaped portion may be larger than the minimum center-to-center distance of the dot-shaped portion.

  The diameter of the dot-shaped portion or the minimum center-to-center distance of the dot-shaped portion is, for example, in the range of 0.085 to 0.508 mm (about 300 to about 50 dots per inch), and typically 0.085 to 0.169 mm. Within a range of (about 300 to about 150 dots per inch). When this dimension is increased, it is difficult to display a high-definition image when a face image is displayed in the image cells 12a, 12a ', 12b, and 12b'. If this dimension is reduced, the reproducibility of the pattern shape of the image cell is lowered.

  When image cells having different spatial frequencies from the image cells 12a, 12a ′, 12b, and 12b ′ are also provided, the image cells having different spatial frequencies are overlapped with the image cells 12a, 12a ′, 12b, and 12b ′. Can be lined up. For example, a full-color multi-tone image can be obtained by overlapping / arranging image cells having different spatial frequencies so that the color appearance at a fixed point becomes three colors of R, G, and B.

  Next, among the transfer material layer formed on the support 21, the portions used as the image cells 12a, 12a ′, 12b, and 12b ′ are thermally transferred from the support 21 to the substrate 11 shown in FIGS. To do. For this thermal transfer, for example, a hot stamp is used. Instead of thermal transfer using a hot stamp, thermal transfer using a thermal roll or a thermal head may be performed. The image display body 12 is affixed on the base material 11 as described above.

  An adhesive anchor layer may be formed on the base material 11 in order to increase the adhesive strength.

  When it is difficult to adhere the image display body 12 to the base material 11 with high adhesive strength, a portion of the transfer material layer used as the image display body 12 is thermally transferred to the base material 11 through the adhesive layer. May be. For example, an adhesive ribbon may be used. If this is used, the adhesive strength between the image display body 12 and the substrate 11 can be increased. In addition, according to this method, as shown in FIG. 10, the structure where the adhesive layer 36 intervened between the image display body 12 and the base material 11 is obtained.

  After the image display body 12 is thermally transferred to the substrate 11 as described above, necessary steps are appropriately performed. In this way, the personal authentication medium 100 described with reference to FIGS. 2 to 5 is obtained.

  When the image cells 12a, 12a ′, 12b, and 12b ′ are formed directly on the substrate 11 by thermal transfer using a thermal head, it is difficult to achieve high image quality due to the surface roughness of the substrate 11 and the like. . On the other hand, in the above-described method, the image cells 12a, 12a ′, 12b, and 12b ′ are not directly formed on the substrate 11. That is, in this method, first, the film is formed on the peeling protection layer 33, and then transferred to the base material 11 together with the peeling protection layer 33. Therefore, the surface roughness or the like of the base material 11 does not greatly affect the image quality.

  The personal authentication medium 100 as a passport has been exemplified above, but the technique described above for the personal authentication medium 100 can also be applied to other personal authentication media. For example, this technology can be applied to various cards such as a visa and an ID card.

  The material of the base material to which the image display body 12 is attached may be other than paper. For example, the base material to which the image display body 22 is attached may be a plastic substrate, a metal substrate, a ceramic substrate, or a glass substrate.

<Example 1: Production of image forming body D1>
A thermal hologram ribbon 200 shown in FIG. 7 was manufactured as follows.

  First, a polyethylene terephthalate film having a thickness of 12 μm was prepared as the support 21. A release layer 27 and a thermoplastic resin layer were formed in this order on the support 21 using a gravure coater, and these were dried in an oven. An acrylic resin was used as the material of the release layer 27, and an acrylic polyol was used as the material of the thermoplastic resin layer. The film thickness after drying of the peeling layer 27 and the thermoplastic resin layer was 0.6 μm and 0.7 μm, respectively.

  Next, two types of diffraction structures as holograms were formed on the surface of the thermoplastic resin layer by hot pressing using a roll embossing device. At this time, the depths of the two types of diffraction structures formed were about 60 nm and about 100 nm, the spatial frequency was the same at 1000 lines / mm, and the grating angles were also the same.

  Next, a reflective layer 25 made of zinc sulfide was formed on the fine unevenness forming layer 24 by vapor deposition. The thickness of the reflective layer 25 was 50 nm.

  Further, the adhesive layer 26 was formed by printing a polyester resin which is a thermoplastic resin on the reflective layer 25. The film thickness of the adhesive layer 26 was 0.6 μm.

  As described above, the thermal hologram ribbon 200 shown in FIG. 7 was completed.

  Next, the image forming body 300 shown in FIG. 9 was manufactured by the following method.

  First, a polyethylene terephthalate film having a thickness of 25 μm was prepared as the support 31. A peeling protective layer 33 and a resin layer 38 were formed in this order on the support 31 using a gravure coater, and these were dried in an oven. Acrylic resin was used as the material for the peel protection layer 33, and acrylic polyol was used as the material for the resin layer 38. The film thicknesses after drying of the peeling protective layer 33 and the resin layer 38 were 1.2 μm and 1.0 μm, respectively.

  Next, the image cells 12a, 12a ', 12b, 12b' were transferred from the support 21 onto the resin layer 38 by performing thermal transfer using a 300 dpi thermal head. For this purpose, first, image processing was performed so that the face image of the owner information display unit had 5 gradations. The transfer of the image cell is a portion of the hologram ribbon where a diffractive structure with a depth of 100 nm is formed, and the gradation of the high-intensity portion of the original image is displayed in two steps by changing the printing area, and the depth of 60 nm. The gradation of the low-brightness part of the original image was displayed in two stages by changing the printing area in the part where the diffraction structure of 1 was formed. At this time, the print areas of both diffraction structures are two types: the maximum size under the condition that the adjacent dot-shaped portions do not overlap and the half size.

  As described above, an image forming body having five gradation levels including a portion where nothing is printed was completed. Hereinafter, this image forming body is referred to as “image forming body D1”.

<Example 2: Production of image forming body D2>
The thermal hologram ribbon 200 shown in FIG. 8 was manufactured as follows.

  First, a polyethylene terephthalate film having a thickness of 12 μm was prepared as the support 21. A release layer 27 and a thermoplastic resin layer were formed in this order on the support 21 using a gravure coater, and these were dried in an oven. An acrylic resin was used as the material of the release layer 27, and an acrylic polyol was used as the material of the thermoplastic resin layer. The film thickness after drying of the peeling layer 27 and the thermoplastic resin layer was 0.6 μm and 0.7 μm, respectively.

  Next, a diffraction structure as a hologram was formed on the surface of the thermoplastic resin layer by hot pressing using a roll embossing apparatus. At this time, the depth of the diffraction structure is about 100 nm, and the spatial frequency is 1000 lines / mm.

  Next, a reflective layer made of ZnS was formed on the fine unevenness forming layer 24 by vapor deposition. At this time, the film thickness was two types of 20 nm and 80 nm.

  Furthermore, the adhesive layer 26 was formed by printing polyester resin which is a thermoplastic resin on this reflective layer. The film thickness of the adhesive layer 26 was 0.6 μm.

  As described above, the thermal hologram ribbon 200 shown in FIG. 8 was completed.

  Next, the image forming body 300 shown in FIG. 9 was manufactured by the following method.

  First, a polyethylene terephthalate film having a thickness of 25 μm was prepared as the support 31. A peeling protective layer 33 and a resin layer 38 were formed in this order on the support 31 using a gravure coater, and these were dried in an oven. Acrylic resin was used as the material for the peel protection layer 33, and acrylic polyol was used as the material for the resin layer 38. The film thicknesses after drying of the peeling protective layer 33 and the resin layer 38 were 1.2 μm and 1.0 μm, respectively.

  Next, the image cells 12a, 12a ', 12b, 12b' were transferred from the support 21 onto the resin layer 38 by performing thermal transfer using a 300 dpi thermal head. For this purpose, first, image processing was performed so that the face image of the owner information display unit had 5 gradations. The image cell is transferred by changing the printing area at the portion of the hologram ribbon where the ZnS reflective layer having a thickness of 50 nm is formed, and displaying the gradation of the high-luminance portion of the original image in two stages. The gradation of the low-luminance portion of the original image was displayed in two stages by changing the printing area in the portion where the reflective layer was formed. At this time, the print areas of both diffraction structures are two types: the maximum size under the condition that the adjacent dot-shaped portions do not overlap and the half size.

  As described above, an image forming body having five gradation levels including a portion where nothing is printed was completed. Hereinafter, this image forming body is referred to as “image forming body D2.”

<Example 3: Production of image forming body D3>
First, a thermal hologram ribbon 200 was produced by the same method as shown in Example 2 except that the thickness of the ZnS reflective layer was constant at 50 nm.

  Next, the image forming body 300 shown in FIG. 9 was manufactured by the following method.

  First, a polyethylene terephthalate film having a thickness of 25 μm was prepared as the support 31. A peeling protective layer 33 and a resin layer 38 were formed in this order on the support 31 using a gravure coater, and these were dried in an oven. Acrylic resin was used as the material for the peel protection layer 33, and acrylic polyol was used as the material for the resin layer 38. The film thicknesses after drying of the peeling protective layer 33 and the resin layer 38 were 1.2 μm and 1.0 μm, respectively.

  Next, the image cell was transferred from the support 21 onto the resin layer 38 by performing thermal transfer using a 300 dpi thermal head. The transfer of the image cell is based on the same five-gradation face image used in Examples 1 and 2, and the print area is maximized under the condition that adjacent dot-shaped portions do not overlap with each other. , 1/2, and 1/4 size, and an image forming body was completed. Hereinafter, this image forming body is referred to as “image forming body D3”.

  As a result of observing the image forming bodies D1 to D3 manufactured as described above, the image forming bodies D1 and D2 form a face image that becomes an owner information display section with gradation in five stages based on the original image. And displayed images with excellent image quality. On the other hand, with respect to the image forming body D3, the maximum size of the printing area under the condition that the adjacent dot-shaped portions do not overlap with each other, and the luminance of the portion formed by the ¾-sized dot-shaped portion is substantially the same. In addition, the dot-shaped portion having the ¼ size was not formed, and as a result, the face image serving as the owner information display portion had gradation only in three stages.

  The image forming body 300 is manufactured by the process shown in FIG. FIG. 11 is a schematic view showing an example of a process for manufacturing the image forming body 300.

  In FIG. 11, reference numeral 201 denotes an image input device such as an imaging device, which inputs an image such as a face photograph to the image processing device 202. The image processing apparatus 202 uses, for example, a personal computer, processes the image input from the image input apparatus 201, forms an image cell as described in the above embodiment, and outputs it to the transfer print control apparatus 204. To do. The transfer printing control device 204 includes a thermal head 205, controls the thermal head 205 in accordance with image cell information sent from the image processing device 202, performs thermal transfer recording using the thermal hologram ribbon 200, and forms an image. A body 300 is produced.

  DESCRIPTION OF SYMBOLS 1 ... Owner information display part, 2 ... Owner information printing part, 100 ... Personal authentication medium, 200 ... Thermosensitive hologram ribbon, 210 ... Transfer material layer, 300 ... Image forming body, 310 ... Laminated body, 11 ... Base material, DESCRIPTION OF SYMBOLS 21, 31 ... Support body, 12 ... Image display body, 12a, 12a ', 12b, 12b' ... Image cell, 13, 33 ... Peeling protective layer, 24, 34 ... Fine uneven | corrugated formation layer, 25, 25 ', 35 ... Reflective layer, 26, 36 ... Adhesive layer, 27, 37 ... Release layer, 38 ... Resin layer, H1, H2, ... High diffractive efficiency fine concavo-convex forming part, H1 ', H2' ... Low diffractive efficiency fine concavo-convex forming part , 201 ... an image input device, 202 ... an image processing device, 203 ... a roll, 204 ... a transfer printing control device, 205 ... a thermal head.

Claims (9)

A method for producing an image forming body having a plurality of gradations, comprising an owner information display unit that displays information about an owner as an image on at least one surface of a transparent substrate,
The owner information display unit includes a plurality of image cells formed in a dot shape,
The plurality of image cells sequentially include an OVD layer that forms an image of information about the owner, a reflective layer and an adhesive layer that are stacked on the OVD layer,
The OVD layer is provided by thermal transfer of two or more thermal hologram ribbons having the same spatial frequency and different diffraction efficiency,
The thermal hologram ribbon is formed from fine irregularities of a hologram or a diffraction grating,
The image forming body is at least,
(1) A thermal hologram ribbon manufacturing step in which two or more thermal hologram ribbons having different diffraction efficiencies are arranged in a specific cycle in the thermal transfer flow direction;
(2) an image reading process for reading an image with gradation;
(3) a step of recording two or more thermal hologram ribbons according to the gradation of the image with the gradation, changing the printing area for each image cell;
A method for producing an image forming body, comprising: a step comprising:   In the manufacturing step (3) of the image forming body, the gradation-graded image is divided into a plurality of layers according to the gradation, and a thermal hologram ribbon having the same number of different diffraction efficiencies as the number of the divided layers is used. 2. A thermal hologram ribbon having a diffraction efficiency corresponding to each layer is produced in each layer, including a step of recording gradations by changing a printing area for each image cell. A method for producing an image-forming body as described in 1.   The method for producing an image forming body according to claim 1, wherein the diffraction efficiency of the thermal hologram ribbon is controlled by the depth of fine irregularities.   The method for producing an image forming body according to claim 1, wherein the diffraction efficiency of the thermosensitive hologram ribbon is controlled by a thickness of a reflective layer laminated on the OVD layer.   An image forming body produced by using the production method according to claim 3.   An owner information printing unit that prints an image having the same appearance as the image displayed on the owner information display unit, and the owner information display unit and the owner information printing unit are visible from the same direction. The image forming body according to claim 5.   The area of the image printed on the owner information print layer is within a range of 0.1 to 30 times the area of the image displayed on the owner information display unit. Image forming body.   A personal authentication medium formed by transferring the image forming body according to claim 5 onto a transfer substrate.   9. The personal authentication medium according to claim 8, wherein a pattern of a chromatic pattern, which is a pattern in which fine lines are combined, is printed in advance on a surface of the substrate to which the image is to be transferred.

Images