JP6051504B2 - Image display, personal authentication medium and blank medium - Google Patents

Description

  The present invention relates to an image display body, an individual authentication medium, and a blank medium using an image display technique that can be used for personal authentication, for example.

  Many personal authentication media such as passports and ID (identification) cards use facial images to enable visual personal authentication.

  Conventionally, for example, in a passport, photographic paper on which a face image is printed is pasted on a booklet. However, such a passport may be tampered with by changing the photo print.

  Therefore, in recent years, face image information has been digitized and reproduced on a booklet. As this image reproduction method, for example, a thermal transfer recording method using a transfer ribbon has been studied.

  However, recently, thermal transfer recording printers using sublimation dyes or colored thermoplastic resins have become widespread. Considering this situation, it is not always difficult to remove a face image from the passport and record another face image in that portion.

  By the way, a phosphor printed matter having a configuration in which a face image is recorded using the image display technique as described above and a face image is recorded thereon using fluorescent ink has been proposed (Patent Document 1). In addition, an anti-counterfeit image forming body (Patent Document 2) in which a face image is recorded using an ink containing a colorless or light-colored fluorescent dye and a colored pigment, and further formed using a normal face image and a pearl pigment. A personal authentication medium in which face images are arranged side by side has been proposed (Patent Document 3).

  Therefore, if the image display technique as described above is applied to a passport, the falsification becomes more difficult. However, a face image recorded using a fluorescent material cannot be observed unless a special light source such as an ultraviolet lamp is used. Further, although a face image formed using a pearl pigment is visible with the naked eye, since the particle size of the pearl pigment is large, it is difficult to form a high-definition image using the pearl pigment.

  Further, when the appearance of the face image recorded on the personal authentication medium is simple and has no visual effect, the falsification is compared with the case where the face image has a complicated and characteristic visual effect. Is easy. Further, when the face image is displayed in a simple manner, it is difficult to easily visually determine the falsified and forged face image.

JP 2000-141863 A JP 2002-226740 A Japanese Patent Laid-Open No. 2003-170685

  The present invention has been made to solve the above-described problems, and is an image that is difficult to tamper with, can exhibit a more complex and characteristic visual effect, and can easily recognize authenticity by visual inspection. An object is to provide a display, a personal authentication medium, and a blank medium.

In order to solve the above-mentioned problem, the invention corresponding to claim 1 is an image display body which displays an image including personal information transferred from a support onto a base material of a personal authentication medium, peelably supported on the support member, and a base layer having an optical transparency include holograms and / or diffraction grating, and an image display layer disposed in front Symbol underlayer on the image display layer includes first The first region and the second region have different ranges in which the diffracted light is emitted under specific illumination conditions, and the first region and the second region have different regions. The range of emission is larger than the range of diffracted light emitted from the second region, the range of diffracted light emitted from the second region is included in the range of diffracted light emitted from the first region, and Holograms and / or diffraction gratings in one region and the second region are individually It is the image display body arrange | positioned with the image of the confidential information containing human information.

According to a second aspect of the present invention, when the first region is observed from a first observation direction under a specific illumination condition, the first image of confidential information including personal information is used as a diffraction image. Display
When the first region and the second region are observed from a second observation direction different from the first observation direction under the specific illumination condition, a second image including personal information is diffracted. The image display body according to the first aspect of the present invention is displayed as an image.

According to a third aspect of the present invention, the first region and the second region of the image display layer include the hologram that displays the second image as a diffraction image under the specific illumination condition, and / or an image display body according to the invention the brightness of the diffraction grating corresponds to equal I請 Motomeko 2.

  According to a fourth aspect of the present invention, the image of the confidential information is not observed from the front direction with respect to the image display body under a specific illumination condition. The image display body according to the invention corresponding to the item.

  The invention corresponding to claim 5 is the image display body according to any one of claims 1 to 4, wherein the personal information includes a face image.

  The invention according to claim 6 is the image display according to any one of claims 1 to 5, wherein the image of the confidential information is an image including another part of the personal information. Is the body.

Further, invention comprises a base material, the lower and the image display layer includes from the substrate side to the image display body mounting serial to any one of claims 1 to 6 corresponding to claim 7 It is a personal authentication medium characterized by comprising a stratum in this order .

Furthermore, an invention corresponding to claim 8 is a blank medium used for manufacturing an image display body that displays an image including personal information described in the invention corresponding to any one of claims 1 to 6. And a support, and a transfer material layer that is releasably supported on the support,
The transfer material layer includes at least a diffractive structure forming layer, and the diffractive structure forming layer includes at least two types of holograms and / or diffraction gratings having different diffracted light emission ranges under specific illumination conditions. One of the two types of holograms and / or diffraction gratings is a blank medium having a larger range in which diffracted light is emitted than the other holograms and / or diffraction gratings.

  According to the present invention, it is possible to provide an image display body, a personal authentication medium, and a blank medium that are difficult to tamper with, can display an image with a distinctive visual effect with excellent image quality, and can easily determine authenticity.

  According to the invention corresponding to claim 1, the image of the confidential information can be confirmed by observing from a specific range, and the image of the confidential information cannot be confirmed from the other range.

  Therefore, authenticity can be easily determined by using this image display body as a personal authentication medium. Furthermore, such a process for recording an image of confidential information requires accuracy and is difficult to manufacture. Therefore, this image display body is difficult to tamper with.

  Furthermore, a part of personal information is displayed using a hologram and / or a diffraction grating. It is very difficult to tamper with personal information displayed by the hologram and / or diffraction grating. And this image display body is affixed on the base material of a personal authentication medium by thermal transfer. Thus, the image display body affixed to the base material of the personal authentication medium is easily destroyed when it is peeled off from the base material. Therefore, when this image display body is used, a personal authentication medium that is difficult to falsify is obtained.

  According to the invention corresponding to claim 2, when observing from the second observation direction under a specific illumination condition, the second image can be observed, and it is concealed when observed from the first observation direction. The first image of information can be observed, and authenticity can be easily determined.

  According to the invention corresponding to claim 3, in general, when the range in which the diffracted light is emitted is different for holograms, diffraction gratings, etc., that is, when the viewing zone is different, the brightness of the diffracted light to be observed is different, and the diffracting range The narrower the brightness, the brighter. For this reason, when a concealed image is recorded using a diffraction grating with a different range of emitting diffracted light, the concealed image can be confirmed by the difference in brightness of the diffracted light even in an area where the image should not be observable (here, the first direction). End up. From this, it is possible to prevent the shadow of the concealed image from being observed by making the luminance of the hologram and / or the diffraction grating in the region where the concealed image is recorded equal to the luminance of the other region.

  According to the invention corresponding to claim 4, the second observation direction is a region centered around the front of the image display body, and the first observation direction is a region slightly outside the region, so that the front direction When observed more, the image of the confidential information is not observed, and the image of the confidential information can be observed in a direction slightly inclined from the front direction.

  According to the invention corresponding to claim 5, if the image is observed from the front direction of the image display layer, the face image of the personal information can be observed, and if the image is observed in a direction slightly inclined from the front direction, An image of confidential information can be observed together with a face image of personal information. A face image is common as biometric information, and is suitable for visual personal authentication.

  According to the invention corresponding to claim 6, a face image can be observed from the front direction, and other personal information can be observed if the image is observed in a direction slightly inclined from the front direction. As other personal information, for example, in the case of a passport, information such as name, date of birth, country name, place of issue, number is recorded, and in the case of an ID card, information such as company name and affiliation is recorded. By recording, even if this image display body is forged, it is possible to determine authenticity by confirming the image of the confidential information.

  According to the invention corresponding to claim 7, the adhesive layer firmly adheres the image display body to the base material when the image display body is transferred from the support onto the base material of the personal authentication medium. Further, the adhesive layer has an effect of making it difficult to replicate the hologram and / or the diffraction grating.

  According to the invention corresponding to claim 8, the personal authentication medium including the image display body having the structure according to any one of claims 1 to 7 makes it difficult to falsify and It is possible to provide a personal authentication medium capable of displaying an image of a visual effect with a superior image quality and capable of easily determining authenticity.

  By using the blank medium of the invention corresponding to claim 9 as a personal authentication medium, it is difficult to tamper with, and it is possible to display a characteristic visual effect image with excellent image quality, and to easily determine the authenticity. It is possible to provide a simple personal authentication medium.

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 display body contained in the personal authentication medium of FIG. Sectional drawing along the AA of the image display body shown in FIG. The top view which expands and shows other part of the image display body contained in the personal authentication medium of FIG. Sectional drawing along the BB line of the image display body shown in FIG. Sectional drawing which shows roughly an example of the blank medium which can be used for manufacture of the image display body shown in FIG. 2 thru | or FIG. Sectional drawing which shows schematically an example which transcribe | transferred the blank medium shown in FIG. 6 to intermediate transfer foil. Sectional drawing which shows roughly an example which transcribe | transferred the intermediate transfer foil shown in FIG. 7 to a to-be-transferred body. The top view which shows roughly an example of the concealment image of the image display body shown in FIG. Sectional drawing along CC line which shows roughly the visual field of the image display body shown in FIG. The top view which shows roughly an example of the diffraction grating shape contained in the image display body shown in FIG. FIG. 10 is a plan view schematically showing an example of another diffraction grating shape included in the image display shown in FIG. 9. The top view which shows roughly an example of the blank medium which concerns on one embodiment of this invention. The top view which shows roughly an example of the display image of the image display body which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described 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.
The personal authentication medium 100 is a booklet such as a passport, and FIG. 1 shows an open booklet. The personal authentication medium 100 includes a signature 1 and a cover 2.

  The signature 1 is composed of one or more pieces of paper 11 and typically has a print pattern 12 such as a character string and a background pattern on the piece of paper 11. The signature 1 is formed by folding one sheet piece 11 or a bundle of a plurality of sheet pieces 11 into two. The paper piece 11 incorporates an IC (integrated circuit) chip for recording personal information and a transmission / reception antenna that can write and read information necessary for the IC chip by non-contact wireless communication.

  The cover 2 is folded in half. The cover 2 and the signature 1 are overlapped so that the signature 1 is sandwiched by the cover 2 with the booklet closed, and are integrated by binding or the like at the positions of the folds.

  On the cover 2, an image including personal information is displayed. The personal information includes personal authentication information used for personal authentication. Personal information can be classified into, for example, biological information and non-biological personal information.

  The biological information is unique to the individual among the characteristics of the biological body. Typically, biological information has characteristics that can be identified by an optical technique. For example, the biometric information is at least one image or pattern of a face, fingerprint, vein, and iris.

  Non-biological personal information is personal information other than biological information. For example, the non-biological personal information is at least one of name, date of birth, age, blood type, gender, nationality, address, permanent address, telephone number, affiliation, and status. The non-biological personal information may include characters input by typing, may include characters input by machine reading a handwriting such as a signature, or may include both of them. .

  In FIG. 1, a plurality of images 13 a, 13 b, 14, and 15 are displayed on the cover 2. The images 13a, 14 and 15 are images displayed using light absorption. Specifically, the images 13a, 14 and 15 are images that are visible when illuminated with white light and observed with the naked eye. One or more of these images 13a, 14 and 15 may be omitted.

  Images 13a, 14 and 15 can be composed of, for example, dyes and pigments. As a method for forming the images 13a, 14 and 15 using these dyes and pigments, 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 may be used. it can. Alternatively, the images 13a, 14 and 15 can be formed by forming a layer containing a thermal color former and drawing on this layer with a laser beam. Alternatively, a combination of these several methods can be used. At least a part of the images 14 and 15 may be formed by a thermal transfer recording method using a hot stamp, may be formed by a printing method, or may be formed using a combination thereof.

  On the other hand, the image 13b is an image displayed by the hologram and / or the diffraction grating. As will be described in detail later, the image 13b is formed by performing, for example, thermal transfer recording using a thermal head and thermal transfer recording using a hot stamp or a heat roll in this order.

  The images 13a and 13b include face images of the same person. The face image included in the image 13a and the face image included in the image 13b may be the same or different. The face image included in the image 13a and the face image included in the image 13b may have the same or different dimensions. Each of the images 13a and 13b may include other biometric information instead of the face image, and may further include biometric information other than the face image in addition to the face image.

  The image 13b may include non-biological personal information instead of the biological information, and may further include non-biological personal information in addition to the biological information. Further, the image 13b may include non-personal information instead of personal information, and may further include non-personal information in addition to the personal information.

  The image 14 includes non-biological personal information and non-personal information. The image 14 includes, for example, one or more characters, symbols, codes, and marks.

  The image 15 is a background pattern. For example, when the image 15 and at least one of the images 13a and 13b are combined, the personal authentication medium 100 can be made more difficult to falsify.

  Next, the structure of the cover 2 will be described with reference to FIGS.

  FIG. 2 is an enlarged plan view showing a part of the image display body included in the personal authentication medium 100 of FIG. FIG. 3 is a cross-sectional view taken along line AA of the image display body shown in FIG. FIG. 4 is an enlarged plan view showing another part of the image display body included in the personal authentication medium 100 of FIG. FIG. 5 is a cross-sectional view taken along line BB of the image display body shown in FIG.

  The structure of the image display body shown in FIGS. 2 and 3 is a portion corresponding to the image 13a in the cover 2. On the other hand, the structure of the image display body shown in FIGS. 4 and 5 is a portion corresponding to the image 13 b in the cover 2. The X direction is the horizontal direction of the display image in a direction parallel to the display surface of the image display body, and the Y direction is a direction parallel to the display surface of the image display body and perpendicular to the X direction. The Z direction is a direction perpendicular to the X direction and the Y direction.

  As shown in FIGS. 3 and 5, the cover 2 includes a cover body 21 and an image display body 22. The cover main body 21 is a base material of the personal authentication medium 100 and is typically a piece of paper. The cover body 21 may have either a single layer structure or a multilayer structure. When the personal authentication medium 100 is closed, the cover body 21 is folded in half so as to sandwich the signature 1.

  The image display body 22 is a layer having a multilayer structure. The image display body 22 is affixed to the main surface of the cover body 21 that faces the signature 1 when the personal authentication medium 100 is closed.

  The image display body 22 includes an image display layer 210 (or 220a) and a peeling protection layer 227. The image display layer 210 displays the image 13a using light absorption. As shown in FIGS. 2 and 3, the image display layer 210 has a pattern shape corresponding to the image 13a. The image display layer 210 can be composed of at least one of a dye and a pigment and an arbitrary resin. Such an image display layer 210 can be formed using, for example, a thermal transfer recording method using a thermal head, an inkjet recording method, an electrophotographic method, or a combination of two or more thereof.

  The image display layer 210 may not be patterned. That is, the image display layer 210 may be a continuous film. In this case, the image display layer 210 can be obtained, for example, by forming a layer containing a thermal color former and drawing on this layer with a laser beam.

  On the other hand, the image display layer 220a shown in FIGS. 4 and 5 includes a hologram and / or a diffraction grating. The image display layer 220a has a pattern shape corresponding to the image 13b.

The structure and formation method of the image display layer 220a will be described in detail later.

  The peeling protection layer 227 has a role of covering the cover body 21 and the image display layers 210 and 220a. The release protective layer 227 has light transmissivity and is typically transparent. The peeling protection layer 227 is made of, for example, a resin.

Note that, in the portion corresponding to the image 14 in the cover 2, for example, a structure similar to that described above with respect to the portion corresponding to the image 13a can be adopted except that the displayed image is different. The portion corresponding to the partial image 14 corresponding to the image 13 a of the cover 2 may have the same stack structure or may have a different laminated structure.

  Next, a method for manufacturing the personal authentication medium 100 and the structure of the image display layer 220a will be described with reference to FIGS.

  FIG. 6 is a cross-sectional view schematically showing an example of a blank medium 201 that can be used for manufacturing the image display body shown in FIGS.

  The blank medium 201 is, for example, a transfer ribbon. The blank medium 201 includes a support 221 and a transfer material layer 220 that is releasably supported by a release layer 222.

The support body 221 is, for example, a resin film or a sheet. The support 221 is made of a material having excellent heat resistance such as polyethylene terephthalate. On the main surface supporting the transfer material layer 220 of the support 221, for example, a release layer containing a fluororesin or a silicone resin may be provided.

  The transfer material layer 220 includes a release layer 222, a diffraction structure forming layer 223, a reflective layer 224, and an adhesive layer 225.

  The release layer 222 is formed on the support 221. The release layer 222 serves to stabilize the release of the transfer agent layer 220 from the support 221 and to promote adhesion of the image display layer 220a to the cover body 21. The release layer 222 has light transmissivity and is typically transparent. The release layer 222 is made of, for example, a thermoplastic resin. The peeling layer 222 can be omitted.

  The diffraction structure forming layer 223 is formed on the release layer 222. The diffraction structure forming layer 223 includes at least one of a hologram and a diffraction grating as a diffraction structure. Here, the diffractive structure forming layer 223 is a transparent layer having a relief structure as a diffractive structure on the surface. As a material for the transparent layer, a resin such as a photocurable resin, a thermosetting resin, and a thermoplastic resin can be used. The diffraction structure forming layer 223 may be a volume hologram.

  The reflective layer 224 is formed on the diffractive structure forming layer 223. Although the reflective layer 224 can be omitted, when the reflective layer 224 is provided, the visibility of the image displayed by the diffraction structure is improved. As the reflective layer 224, for example, a transparent reflective layer or an opaque metal reflective layer can be used. The reflective layer 224 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 diffraction structure forming layer 223 can be used. The transparent reflective layer made of a transparent material may have either a single layer structure or a multilayer structure. In the latter case, the transparent reflective layer may be designed so as to repeatedly cause reflection interference. As this transparent material, for example, a transparent dielectric such as zinc sulfide and titanium dioxide can be used.

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

  As the opaque metal reflection layer, a metal layer similar to the transparent reflection layer described above can be used except that it is thicker.

  The adhesive layer 225 is formed on the reflective layer 224. The adhesive layer 225 is made of, for example, a thermoplastic resin. The adhesive layer 225 can be omitted.

  Next, FIG. 7 is a sectional view schematically showing an example in which the blank medium shown in FIG. 6 is transferred to the intermediate transfer foil.

  The intermediate transfer foil 301 includes a support 31, for example, a peeling protective layer 32 that serves as a base layer, and an image receiving layer 33 that is supported by the peeling protective layer 32 so as to be peelable. The support 31 is, for example, a resin film or a sheet. The support 31 is made of a material having excellent heat resistance such as polyethylene terephthalate. A release layer containing, for example, a fluororesin or a silicone resin may be provided on the main surface of the support 31 that supports the image receiving layer 33.

  The peeling protective layer 32 serves as a protective layer that stabilizes peeling of the image receiving layer 33 from the support 31 and promotes resistance of the surface of the image receiving layer 33. The peeling protective layer 32 has light transmissivity and is typically transparent. The peeling protection layer 32 is made of, for example, a thermoplastic resin.

  The image receiving layer 33 is made of a material having good adhesion to the adhesive layer 225 of the blank medium 201 shown in FIG. That is, the adhesive layer 225 of the blank medium 201 shown in FIG. 6 and the image receiving layer 33 of the intermediate transfer foil 301 shown in FIG. 7 are brought into close contact with each other and heated from the support 221 side of the blank medium 201 by a thermal head. In 220, the image display layer 220a is printed.

  The display pixels 311 and the display pixels 312 of the image display layer 220a are obtained by printing the transfer material layer 220 of the blank medium 201 by the method described above. The display pixel 311 serving as the first region is a pixel that displays the hidden image, and the display pixel 312 serving as the second region is a pixel that does not display the hidden image. The method for forming the hidden image will be described in detail later.

  Next, FIG. 8 is a cross-sectional view schematically showing an example in which the intermediate transfer foil 301 shown in FIG. 7 is transferred to the cover body 21 that is a transfer target.

  The image receiving layer 33 and the image display layer 220a of the intermediate transfer foil 301 are brought into close contact with the cover body 21 that is a transfer target of the personal authentication medium 4, and the support 31 and the cover body 21 are heated and pressed to adhere. Thereafter, the support 31 is peeled from the personal authentication medium 4 at the interface between the peel protection layer 32 and the support 31.

  Next, a method for forming a hidden image will be described. FIG. 9 is a plan view schematically showing an example of the concealed image of the image display shown in FIG. 10 is a cross-sectional view taken along the line CC of FIG. 9 schematically showing the viewing zone of the image display body shown in FIGS.

  The pixel structure shown in FIG. 9 is an image display layer 220 a printed on the personal authentication medium 4. As described above, the display pixel 311 is a pixel that displays a concealed image, and the concealed image represents the character “S”. The display pixel 312 is a pixel that does not display a hidden image.

  Here, the diffraction grating structure of the transfer material layer 220 of FIG. 6 used for printing of the image display layer 220a is printed using diffraction gratings having different shapes in the display pixel 311 and the display pixel 312. Assuming that the illumination light is a point illumination light source perpendicular to the Y axis and 45 ° above the Z axis in the XZ plane, the state of the light diffracted by the illumination light is as shown in FIG. .

  That is, the range of light in the Y direction diffracted from the display pixel 312 is the viewing area 412, and the range of light in the Y direction diffracted from the display pixel 311 is the viewing area 411. The viewing zone 411 is narrower than the viewing zone 412.

  Here, when the personal authentication medium 4 is observed from the observation range 42, diffracted light from all pixels can be observed. Next, since the observation range 43 is a range in which only the diffracted light from the display pixel 311 is not observed, when the personal authentication medium 4 is observed from the observation range 43, only the display pixel 311 is not illuminated. That is, it is possible to form a hidden image by arranging the display pixels 311.

  As a result, in the viewing zone 411, if the difference from the viewing zone 412 is increased, the range in which the concealed image can be observed is widened. Conversely, if the difference from the viewing zone 412 is reduced, the hidden image can be observed. The range can be narrowed.

  Next, FIG. 11 is a plan view schematically showing an example of the diffraction grating shape included in the image display shown in FIG. The example in FIG. 11 shows an enlarged structure of the diffraction grating of the display pixel 311. The diffraction grating structure Ga has a curved groove structure.

  Next, FIG. 12 is a plan view schematically showing an example of another diffraction grating shape included in the image display shown in FIG. The example of FIG. 12 shows an enlarged structure of the diffraction grating of the display pixel 312. The diffraction grating structure Gb has a curved groove structure.

Here, the curvature of the curve of the diffraction grating structure Ga has a large gentle curve in comparison with the diffraction grating structure Gb. For the diffraction grating structure having such curve, the magnitude of the range of diffusion of the diffracted light in the Y-axis direction is determined by the curvature of the curve. Therefore, the viewing area of the diffracted light of the display pixel 312 is wider than that of the display pixel 311.

Further, the diffusion range of the diffracted light in the X-axis direction is determined by the pitch of the diffractive structure, and in order to diffuse widely, it is necessary to include a plurality of diffraction grating pitches. However, since the X-axis direction also includes diffusion due to light spectroscopy, the X-axis direction diffuses more widely than the Y-axis direction, and the manner of switching to the concealed image gradually changes, making it easy to recognize the concealed image. . Therefore, as a method for recording the concealed image is to use a change in curvature of the diffraction grating.

  Next, a specific method for producing a personal authentication medium will be described. 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 can be obtained as electronic information. This face image is subjected to image processing as necessary.

  Next, an intermediate transfer foil 301 shown in FIG. 7 is prepared. The intermediate transfer foil 301 is a layer having a multilayer structure, and includes a support 31 and a peeling protective layer 32 and an image receiving layer 33 sequentially formed thereon. Note that the peeling protection layer 32 and the image receiving layer 33 constitute a base layer.

  Subsequently, an image display layer 220 a having a pattern corresponding to the previous face image is formed on the intermediate transfer foil 301. Specifically, a part of the transfer material layer 220 is thermally transferred onto the image receiving layer 33 from the support 221 of the blank medium 201 shown in FIG. 6 based on the previous image information.

  Here, using the thermal head, the portion of the transfer material layer 220 that is thermally transferred onto the image receiving layer 33 prints a portion of the pattern corresponding to the previous face image other than the pattern that displays the hidden image. To do.

  Further, the diffraction grating shape of the diffraction structure forming layer 223 of the transfer material layer 220 in the blank medium 201 is the diffraction grating structure of the display pixel 312 shown in FIG. Thereby, the portion of the display pixel 312 can be printed.

  Furthermore, using the transfer material layer 220 in which the diffraction grating shape of the diffraction structure forming layer 223 of the transfer material layer 220 of the blank medium 201 has the diffraction grating structure of the display pixel 311 shown in FIG. Of the corresponding pattern, the pattern portion for displaying the hidden image is printed. Thereby, the portion of the display pixel 311 can be printed.

  Next, since the image display layer 220a obtained as described above is formed by thermal transfer using a thermal head, the image display layer 220a typically includes 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 plane lattice indicated by a broken line in FIG.

  In FIG. 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. 4, the adjacent dot-like portions are arranged so that their outlines touch 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). When a face image is displayed on the image display layer 220a, 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 0.169 mm (about 300 to about 150 dots per inch). Within . The dimensions larger Thus, possible to display a high-definition image on the image display layer 220a becomes difficult. When this dimension is reduced, the reproducibility of the pattern shape of the image display layer 220a is lowered.

  Therefore, the intermediate transfer foil 301 including the support 31, the peeling protective layer 32, the image receiving layer 33, and the image display layer 220a can be obtained according to the above procedure. Next, the image receiving layer 33 and the image display layer 220a of the intermediate transfer foil 301 are brought into close contact with the cover body 21 which is the transfer body of the personal authentication medium 4 shown in FIG. 8 and heated from the support 31 and the cover body 21 side. Transfer is performed under pressure, and the support 31 is peeled off.

  When the personal authentication medium 4 produced as described above is observed from the observation range 42 shown in FIG. 10, a face image can be observed. Further, when observing from the observation range 43, the diffracted light in the concealed image portion of the face image cannot be observed, so that the concealed image appears in the face image.

  Therefore, when the display pixels 311 and 312 are arranged as shown in FIG. 9, all the pixels are filled with the pixels in this range, so that the front part of the face is shining. When the viewpoint is shifted from the front direction, the portion of the letter “S” becomes dark and can be observed as a concealed image.

  By the way, in general, when the area where the diffracted light is emitted is different in a hologram, a diffraction grating, or the like, that is, when the viewing area is different, the brightness of the diffracted light to be observed is different. . For this reason, if a concealed image is recorded using a diffraction grating with a different region for emitting diffracted light, the concealed image can be confirmed by the difference in brightness of the diffracted light even in a region where the concealed image should not be observable (here, the front direction). End up. That is, when observed from the front, the brightness of the portion “S” increases, and the portion is recognized as a character.

  For this reason, it is possible to prevent the shadow of the concealed image from being observed by making the luminance of the diffraction grating in the region where the concealed image is recorded equal to the luminance of the other regions.

  As a method of adjusting the luminance, a method of adjusting the luminance by changing the area is general. In this case, while the pixels of a certain size are continuously arranged, the circumference and the area are When there is a different area, it becomes easy to recognize the area, and there is a possibility that the concealed image can be observed.

  As a method of adjusting the luminance, it is possible to produce a diffraction grating having a constant luminance even when the viewing zone is different by changing the depth of the diffraction grating and adjusting the diffraction efficiency. As a method for adjusting the depth of the diffraction grating, a method of changing the depth of the diffraction grating of the original plate produced by electron beam drawing is effective.

  Next, FIG. 13 is a plan view schematically showing an example of a blank medium according to an embodiment of the present invention.

  A color image is printed to express a face image, and a roll film-like blank medium ribbon 450 is provided with a panel of a red transfer material layer 451, a green transfer material layer 452, and a blue transfer material layer 453. It is. Further, a concealed image transfer material layer 454 is provided, and the panels are sequentially arranged. Further, the position of each panel is adjusted by the positioning mark 455 so that printing can be performed.

  The face image is color-separated into red, green, and blue, and printing is performed on the intermediate transfer foil 301 using the panels of transfer material layers 451 to 453 corresponding to the respective colors, thereby producing the image display layer 220a. Here, the diffraction grating pitch of the panel of the concealed image transfer material layer 454 is set equal to the pitch of the diffraction grating of the red transfer material layer 451, and the viewing area of the concealment image transfer material layer 454 is the red transfer material layer. It is set to be narrower than the viewing area of 451.

  In addition, by multiplying the red data of the face image with the data of the concealed image and printing on the panel of the concealed image transfer material layer 454, the concealed image is included in the red data of the face when observed from an oblique direction. Can be observed. Here, if a concealed image transfer material layer 454 other than red is prepared, a color concealed image can be printed.

  Next, FIG. 14 is a plan view schematically showing an example of a display image of the image display body according to the embodiment of the present invention. Here, the setting of the viewing area of the concealed image transfer material layer 454 is as shown in FIG. The observation image 460 is an image observed from the observation range 42, and only the face image can be observed, and the concealed image cannot be observed.

  Next, the observation image 462 is an image observed from the observation range 43, and a concealed image and a face image can be observed. The observation image 461 is an image when one eye is observed from the range 42 and the other eye is observed from the range 43.

  Since the viewing areas are different in the left-right direction, depending on the observation position, there may be a place where a region where the concealed image can be observed and a region where the hidden image cannot be observed simultaneously enter. For this reason, since the image information has no concealed image on the left and right, it is observed as an image having a very uncomfortable feeling.

  Therefore, it is possible to provide a personal authentication medium that is difficult to reproduce an image having a more complicated and special visual effect, is difficult to be tampered with, and can easily determine the authenticity. .

  The above description exemplifies a personal authentication medium as a passport. However, the image display technology that can be used for this personal authentication can also be applied to other personal authentication media. For example, this technique can be applied to various cards such as a visa and an ID card.

  The base material to which the image display layer 220a is attached may be other than paper. For example, the base material to which the image display layer 220a is attached may be a plastic substrate, a metal substrate, a ceramic substrate, or a glass substrate.

  The image to be displayed on the image display layer 220a may include other biological information in addition to the face image, or may include other biological information instead of the face image. The image displayed on the image display layer 220a may include at least one of non-biological personal information and non-personal information in addition to biometric information, and at least non-biological personal information and non-personal information instead of the biometric information. One may be included.

  The above embodiments are presented as examples, and are not intended to limit the scope of the invention. The embodiment described above can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Signature, 2 ... Cover, 4 ... Personal authentication medium, 11 ... Paper piece, 13a ... Image, 13b ... Image, 14 ... Image, 15 ... Image, 21 ... Cover body, 22 ... Transfer material layer, 42 ... Observation range , 43 observation range, 100 ... personal authentication medium, 201 ... blank medium, 210 ... image display layer, 220a ... image display layer, 220 ... transfer material layer, 222 ... release layer, 223 ... diffraction structure forming layer, 224 ... reflective layer DESCRIPTION OF SYMBOLS 225 ... Adhesion layer, 31 ... Support body, 32 ... Release protection layer, 33 ... Image receiving layer, 311 display pixel, 312 ... Display pixel, 301 ... Intermediate transfer foil, 411 ... Viewing area, 412 ... Viewing area, 450 ... Blank Media ribbon, 451 ... red transfer material layer, 452 ... green transfer material layer, 453 ... blue transfer material layer, 454 ... concealed image transfer material layer, 455 ... positioning mark, 460 ... observation image, 461 ... observation image 462 ... Observation image , Ga ... diffraction structure, Gb ... diffraction structure.

Claims (8)

An image display body that is transferred from a support onto a base material of a personal authentication medium and displays an image including personal information,
An undercoat layer that is releasably supported by the support and has optical transparency;
It includes a hologram and / or grating, before SL and an image display layer disposed on an underlying layer the image display layer includes a first region having at least two regions of the second region, these first The region and the second region have different diffracted light emission ranges under specific illumination conditions, and the diffracted light emission range of the first region is greater than the diffracted light emission range of the second region. The range in which the diffracted light is emitted from the second region is included in the range from which the diffracted light is emitted from the first region, and the hologram and / or the diffraction grating of the first region and the second region are personal information. An image display body characterized in that an image of confidential information including the image is arranged. The first area displays a first image of confidential information including personal information as a diffraction image when observed from a first observation direction under specific illumination conditions;
When the first region and the second region are observed from a second observation direction different from the first observation direction under the specific illumination condition, a second image including personal information is diffracted. The image display body according to claim 1, wherein the image display body is displayed as an image. The first region and the second region of the image display layer have the same brightness of the hologram and / or diffraction grating that displays the second image as a diffraction image under the specific illumination condition. the image display body according to 請 Motomeko 2 you.   The image display according to any one of claims 1 to 3, wherein the image of the confidential information is not observed from a front direction with respect to the image display body under a specific illumination condition. body.   The image display body according to any one of claims 1 to 4, wherein the personal information includes a face image.   The image display body according to any one of claims 1 to 5, wherein the image of the confidential information is an image including another part of the personal information. On a substrate, and comprising the said image display layer and the underlying layer included in the picture image display body according from the substrate side to any one of claims 1 to 6 in this order Personal authentication media. A blank medium used for manufacturing an image display body that displays an image including the personal information according to any one of claims 1 to 6 ,
Including a support and a transfer material layer releasably supported on the support,
The transfer material layer includes at least a diffractive structure forming layer,
The diffractive structure forming layer has at least two types of holograms and / or diffraction gratings having different diffracted light emission ranges under specific illumination conditions,
One of the two kinds of holograms and / or diffraction gratings has a larger range in which diffracted light is emitted than the other holograms and / or diffraction gratings.

Images