JP6531858B2 - Image display device, image display medium, and hologram ribbon - Google Patents

Description

  The technology of the present disclosure relates to an image display device that displays an image, and an image display medium that includes the image display device.

  A passport, which is an example of a personal identification medium, has an owner display unit that displays a face image of the owner. Since the display of the face image by the posting of the face photo has the possibility of falsification due to the replacement of the face photo, the recent owner display unit fixes the face image of the owner on the paper instead of the posting of the face photo. Are adopted (for example, refer to patent documents 1-3). In particular, an OVD (optically variable device) applies an optical thin film including a diffraction grating on a face image, and further thermally transfers a part of a hologram ribbon to a passport and displays the face image by a hologram. Optical Variabke Device) technology is effective in suppressing fraud (see, for example, Patent Document 4).

JP 2002-226740 A JP-A-49-131142 JP, 2006-123174, A JP 10-49647 A

  However, even with a passport using the above-mentioned OVD technology, fraudulent acts such as forgery or falsification of it are not unending. Therefore, there is a need for a technology that can easily determine the authenticity of a face image by visual inspection of the user. The request for facilitating the determination of the authenticity of the image is not limited to the owner display unit of the passport, and is common to the image display devices that display the image using the OVD technology.

  An object of the technology of the present disclosure is to provide an image display device and an image display medium, which can easily determine the authenticity of an image by visual observation.

  An image display device which solves the above-mentioned subject includes a plurality of image cells having a hologram layer and two-dimensionally arranged, and the hologram layer has a one-dimensional lattice pattern extending along a first direction. It is an image display device including a diffraction grating that repeats along a second direction orthogonal to the direction. Further, the plurality of image cells aligned along the second direction and associated with one color are one image cell group. The image cell group is configured such that each of a plurality of the image cells constituting the image cell group displays the same color in a state in which the viewpoint is located in a predetermined direction with respect to the image display device. The larger the distance from one end of the image cell group in the second direction, the smaller the spatial frequency of the diffraction grating is.

  Another image display device which solves the above-mentioned subject is provided with a plurality of image cells which have a hologram layer and are arranged in two dimensions, and the hologram layer has a one-dimensional lattice pattern extending along a first direction. An image display device including a diffraction grating repeating along a second direction orthogonal to the first direction. Further, the plurality of image cells aligned along the second direction and associated with one color are one image cell group. Then, in a state in which the viewpoint is positioned in a predetermined direction with respect to the image display device, the image cell group is configured such that each of a plurality of the image cells forming one image cell group displays the same color. And a portion in which the spatial frequency f of the diffraction grating in the image cell group and the wavelength λ of the light of one color satisfy the following formula (1).

f = (sin α-sin β) / λ (α> β) (1)
The incident angle α is the incident angle of the illumination light to the image display device, and the diffraction angle β is the diffraction angle of the diffracted light passing through the viewpoint in the diffracted light in the grating pattern.

The image display medium which solves the said subject is an image display medium provided with the image display device which displays an owner's face image, Comprising: The said image display device is the above-mentioned image display device.
According to each configuration, since each of the plurality of image cells constituting the image cell group displays the same color, it is possible to determine the authenticity of the image based on whether or not the result of such visual recognition can be obtained.

  In the above-mentioned image display device, in the state where the viewpoint is located in the predetermined direction with respect to the image display device, in the image cell group, each of a plurality of the image cells constituting the image cell group displays a first color The first image cell group is configured of a plurality of the image cells associated with the first color. The plurality of image cells arranged along the second direction and associated with the second color are a second image cell group, and the second image cell group is the image display A second image cell group configured to display the second color in a state in which a viewpoint is positioned in the predetermined direction with respect to the device; It is preferable to include a portion where the spatial frequency of the diffraction grating is smaller as the distance from one end of the second image cell group is larger.

  According to the above configuration, based on whether or not the first color is visually recognized in the first image cell group, and whether or not the second color is visually recognized in the second image cell group The true / false of is determined. Therefore, the accuracy of the result in the determination of the authenticity of the image is enhanced as compared with the configuration in which the authenticity of the image is determined only by the visual observation of the first color.

  In the image display device, the plurality of the image cells arranged along the second direction and associated with the third color are a third image cell group. In the third image cell group, each of a plurality of image cells constituting the third image cell group has the third color in a state in which the viewpoint is located in the predetermined direction with respect to the image display device. Preferably, the larger the distance from the one end of the third image cell group in the second direction to the second direction, the smaller the spatial frequency of the diffraction grating is.

  According to the above configuration, the authenticity of the image is determined based on whether or not different colors are viewed in each of the first image cell group, the second image cell group, and the third image cell group. Is determined. Therefore, the accuracy of the result in the determination of the authenticity of the image is enhanced as compared with the configuration in which the authenticity of the image is determined only by the visual observation of the first color.

  In the image display device, each of all the image cells arranged in the second direction is any one of the first image cell group, the second image cell group, and the third image cell group. It is preferable to belong to one or more.

  According to the above configuration, the authenticity of the image is determined based on whether or not each of the image cells aligned along the second direction belongs to any one of the three colors. The accuracy of the result in the determination of the authenticity of the image is enhanced as compared with the configuration in which the authenticity of the image is determined only by the visual recognition of the image.

In the image display device, it is preferable that a plurality of the image cells include portions overlapping with each other.
According to the above configuration, the definition of the image displayed by the image display device is enhanced.

  In the image display medium, the image display device further includes a second image display unit which is a first image display unit and is a printing unit in which the face image of the owner is represented by the wavelength of light and the amplitude of light. Is preferred.

  According to the above configuration, the authenticity of the face image displayed by the first image display unit is determined also by comparing the face image displayed by the first image display unit with the face image displayed by the second image display unit. It is possible.

In the image display medium, the area of the first image display unit is preferably 0.25 times or more and twice or less the area of the second image display unit.
According to the above configuration, it is possible to easily compare the face image displayed by the first image display unit with the face image displayed by the second image display unit.

  According to the technology of the present disclosure, it is easy to determine the authenticity of the image visually.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the passport of one Embodiment which actualized the image display medium in the technique of this indication in a passport in the state which the paper surface containing a 1st image display part and a 2nd image display part opened. It is a partial expanded plan view which expands and shows a part of plane structure of a single layer display in a 1st image display part, and is a figure shown in the state where a part of image receiving layer was virtually peeled off. FIG. 3 is a partially enlarged cross-sectional view showing a part of a cross-sectional structure of a single-layer display unit in the first image display unit, taken along line 3-3 in FIG. 2; It is a partial enlarged plan view which expands and shows a part of plane structure of the lamination display part in the 1st image display part, and is a figure shown in the state where a part of image receiving layer was virtually peeled off. FIG. 5 is a partial enlarged cross-sectional view showing a part of a cross-sectional structure of a stacked display portion in the first image display portion in an enlarged manner, which is a cross-sectional view taken along line 5-5 of FIG. 4; It is sectional drawing which shows the cross-section of a hologram ribbon. It is a top view which shows the planar structure of a hologram ribbon, Comprising: It is a top view which shows the formation position of a fine concavo-convex forming layer. It is a geometrical optical figure for demonstrating the relationship between the wavelength of the light which the fine grooving | roughness formation layer strengthens, and the spatial frequency in a fine grooving | roughness formation layer. (A) A side view of the fine unevenness forming layer schematically showing the distribution of spatial frequency in the fine unevenness forming layer, and (b) a plane of the fine unevenness forming layer schematically showing the distribution of spatial frequency in the fine unevenness forming layer FIG. It is a process drawing which shows the transfer process which transcribe | transfers a hologram ribbon to a to-be-transferred body, and forms an image cell using the cross-section of a hologram ribbon, Comprising: The state which the hologram ribbon is surface-contacted to a to-be-transferred body FIG. 6B is a view showing the state where an image cell is formed. It is sectional drawing which shows an example of the cross-section of a 1st image display part. FIG. 2 is a block diagram showing an example of the configuration of a transfer device. It is a top view which shows an example of the range transferred in a hologram ribbon. It is a display image figure which shows the observation result of the face image which a 1st image display part displays, Comprising: The figure which shows the observation result of the face image which a 1st image display part of an Example displays. (B) Comparative example It is a figure which shows the observation result of the face image which a 1st image display part displays. It is process drawing which shows the manufacturing method of the image display device in a modification. It is process drawing which shows the manufacturing method of the image display device in a modification.

An embodiment in which the image display medium in the technology of the present disclosure is embodied in a passport will be described with reference to FIGS.
As FIG. 1 shows, the passport 10 is equipped with the 1st image display part 12 which is an example of an image display device, and the 2nd image display part 13. As shown in FIG. The plurality of sheets 11 constituting the passport 10 are, for example, a binding sheet constituting the passport 10, and the first image display unit 12 and the second image display unit 13 are components of the plurality of sheets 11 constituting the passport 10. Among them, it is provided on a sheet 11 showing the identity of the owner.

  The first image display unit 12 has an optical device for displaying the face image of the owner on the sheet of the sheet 11, and the face image of the owner includes the amplitude of the light, the wavelength of the light, and the light It is a part to memorize as a phase of. The first image display unit 12 has a hologram layer including a diffraction grating as an optical device. The first image display unit 12 is formed, for example, by thermal transfer recording of a hologram sheet using a thermal head, hot stamping after thermal transfer recording using a thermal head, or thermal transfer recording using a thermal roll.

  The second image display unit 13 is composed of a pigment, a pigment, etc. for displaying the face image of the owner on the sheet of the sheet 11, and the face image of the owner is composed of the amplitude of the light and the wavelength of the light. It is a part to memorize as. The face image of the owner displayed by the second image display unit 13 has the same appearance as the face image of the owner displayed by the first image display unit 12. The second image display unit 13 may be, for example, a thermal transfer recording method using a thermal head, an inkjet recording method, an electrophotographic method, a laser beam drawing method of irradiating a laser beam to a color forming layer containing a thermal coloring agent, Or it is formed by the method of combining two or more.

  The area of the first image display unit 12 is preferably set, for example, within a range of 0.25 times or more and 2 times or less of the area of the second image display unit 13. When the area of the first image display unit 12 has a magnification within the above range with respect to the area of the second image display unit 13, the image displayed by the first image display unit 12 and the second image display unit The comparison with the 13 displayed images is easy, and the accuracy of the matching between the images is enhanced. In the face image displayed by the first image display unit 12 and the face image displayed by the second image display unit 13, the length of the face image along the vertical direction is the length of the face image along the horizontal direction It is preferred to have the same ratio to one another. Also in such a configuration, the comparison between the image displayed by the first image display unit 12 and the image displayed by the second image display unit 13 is easy, and the accuracy of the matching between the images is enhanced.

  The configuration of the first image display unit 12 will be described with reference to FIGS. 2 to 5. 2 is an enlarged plan view showing the single-layer display unit 12a of the first image display unit 12 in FIG. 1 in an enlarged manner, and FIG. 4 is a laminate display unit 12b of the first image display unit 12 in FIG. Is an enlarged plan view showing the

  As shown in FIG. 2, the portion of the sheet 11 provided with the single layer display portion 12 a includes a paper material 15 and an image receiving layer 16, and the image receiving layer 16 is formed of a light transmitting resin. , The paper material 15 is covered.

  In the single-layer display unit 12a, a plurality of image cells 20 are two-dimensionally arranged on the surface 16a of the image receiving layer 16. The plurality of image cells 20 includes a first image cell 20a, a second image cell 20b, and an image cell 20c. The plurality of image cells 20 have a minute circular shape in plan view. The centers of the plurality of image cells 20 are located on the surface 16 a of the image receiving layer 16 at grid points 16 c of a square grid 16 b which is a virtual plane grid, as indicated by the two-dot chain line in FIG.

  The first image cell 20a has a relief structure in which the amplitude of the light constituting the face image, the wavelength of the light, and the phase of the light are stored. The relief structure is a lattice pattern, which is a groove extending along the lateral direction, repeated along the longitudinal direction orthogonal to the lateral direction. The horizontal direction is an example of a first direction, and the vertical direction is an example of a second direction. The first image cell 20a is a hologram element that uses a relief structure for diffraction, and the plurality of first image cells 20a aligned in the longitudinal direction constitute one first image cell group.

  When illumination light is incident on the first image cell 20a from a predetermined incident angle, the first image cell is configured such that light having a specific wavelength reinforces each other at a fixed point that is a predetermined viewpoint. The spatial frequency of 20a is set. For example, the first image cell 20a has a spatial frequency that reinforces light corresponding to red and is associated with red. The light corresponding to red may be light having a single wavelength or may be light having a wavelength having a certain range, as long as it is light that is viewed as red.

  The second image cell 20b also has a relief structure storing the amplitude of light, the wavelength of light, and the phase of light constituting the face image, and the relief structure of the second image cell 20b is the first. The wavelength different from that of the relief structure of the image cell 20a is stored. The plurality of second image cells 20 b arranged along the vertical direction constitute one second image cell group. When illumination light is incident on the second image cell 20b from a predetermined incident angle, light having a specific wavelength different from that of the first image cell 20a becomes stronger at a fixed point which is a predetermined viewpoint. The spatial frequency of the second image cell 20b is set to match. For example, the second image cell 20b has a spatial frequency that enhances light corresponding to green and is associated with green. The light corresponding to green may be light having a single wavelength or may be light having a wavelength having a certain range, as long as it is light that is recognized as green.

  The third image cell 20c also has a relief structure storing the amplitude of light, the wavelength of light, and the phase of light constituting the face image, and the relief structure of the third image cell 20c is the first. The relief structure of the image cell 20a and the relief structure of the second image cell 20b store different wavelengths. The plurality of third image cells 20c arranged in the longitudinal direction constitute one third image cell group. When illumination light is incident on the third image cell 20c from a predetermined incident angle, a specific point different from the first image cell 20a and the second image cell 20b at a fixed point which is a predetermined viewpoint The spatial frequency of the third image cell 20c is set so that the lights having the wavelengths of 1 to 4 strengthen each other. For example, the third image cell 20c is associated with blue with a spatial frequency that enhances the light corresponding to blue. The light corresponding to blue may be light having a single wavelength or may be light having a wavelength having a certain range, as long as it is light that is viewed as blue.

  As shown in FIG. 3, in the single layer display unit 12a, a plurality of image cells 20 constituting the first image display unit 12 are located on the surface 16a of the image receiving layer 16. The image receiving layer 16 has a function of adhering each of the plurality of image cells 20 to the paper material 15. The plurality of image cells 20 divides the surface 16 a of the image receiving layer 16 into a single layer cell region where the image cell 20 is located and a non-cell region where the image cell 20 is not located.

  As shown in FIG. 4, the portion of the sheet 11 provided with the stacked display portion 12 b is provided with the paper material 15 and the image receiving layer 16 as in the portion provided with the single layer display portion 12 a. Similar to the single-layer display unit 12a, a plurality of image cells 20 are two-dimensionally arranged on the surface 16a of the image receiving layer 16 in the laminated display unit 12b. The plurality of image cells 20 have a substantially square shape in plan view, and are located at lattice points 16c of a square lattice 16b which is a virtual plane lattice, as indicated by a two-dot chain line in FIG. The stacked display unit 12b has a portion in which any one of the first image cell 20a, the second image cell 20b, and the third image cell 20c is continuous along the vertical direction. A portion where image cells 20 of the same type are aligned in the longitudinal direction has a band shape in which the image cells 20 of that type extend in the longitudinal direction.

  As illustrated in FIG. 5, the stacked display unit 12 b has a portion in which two image cells 20 are stacked. The two stacked image cells 20 may be two different types of image cells 20 among the first image cell 20a, the second image cell 20b, and the third image cell 20c. It may be one type of image cell 20 selected in advance. In FIG. 5, a portion where the third image cell 20c is stacked on the second image cell 20b and a portion where the other third image cell 20c is stacked on the third image cell 20c are illustrated.

  The virtual plane lattice that determines the position of the image cell 20 is not limited to the square lattice 16b, and may be another lattice such as a triangular lattice or a rectangular lattice. Further, in the positions of the image cells 20 adjacent to each other, the outlines of the image cells 20 may be in contact with each other at one point, or parts of the image cells 20 may overlap each other. The contours may be separated from each other. In the image cells 20 adjacent to each other, the center-to-center distance between the image cells 20 is preferably 0.085 mm or more and 0.508 mm or less, in other words, about 300 dpi or more and about 50 dpi or less. Further, in the image cells 20 adjacent to each other, the center-to-center distance between the image cells 20 is more preferably 0.085 mm or more and 0.169 mm or less, in other words, about 300 dpi or more and about 150 dpi or less. If the center-to-center distance between the image cells 20 adjacent to each other is within the above range, a fine face image can be obtained by the plurality of image cells 20. In addition, if the center-to-center distance between the image cells 20 adjacent to each other is within the above range, the reproducibility of the face image displayed by the plurality of image cells 20 is enhanced.

With reference to FIGS. 6-9, the detailed structure of the 1st image display part 12 is demonstrated with the manufacturing method. First, the hologram ribbon 30 used for manufacturing the first image display unit 12 will be described.
As shown in FIG. 6, the hologram ribbon 30 includes a support 31, and the support 31 is a multilayer composed of a peeling protection layer 32, a fine unevenness forming layer 33, a transparent reflection layer 34, and an adhesive layer 35. The transfer body 36 which is a structure is in contact. The support 31 and the adhesive layer 35 sandwich the peeling protective layer 32, the fine asperity forming layer 33, and the transparent reflective layer 34, and the peeling protective layer 32 and the transparent reflective layer 34 sandwich the fine asperity forming layer 33. There is.

  The support 31 is, for example, a resin film and a resin sheet including a flat resin thin plate having a surface that is thicker than the resin film and sufficiently wider than the thickness, such as polyethylene terephthalate It is preferable to form from the material excellent in heat resistance. The release surface 31 a of the support 31, which is a surface in contact with the release protective layer 32 in the support 31, has a release layer containing, for example, a fluorocarbon resin or a silicone resin, between the release surface 31 a and the release protective layer 32. It may be provided.

  The peeling protective layer 32 is a layer having light transmittance and is preferably transparent, and is formed of, for example, a thermoplastic resin. The peeling protective layer 32 has a function of enhancing the stability of peeling of the transfer body 36 from the support 31 and a function of promoting adhesion between the image cell 20 and the image receiving layer 16. The peeling protective layer 32 may be omitted as long as the peeling property of the transfer member 36 from the support 31 and the adhesion between the image cell 20 and the image receiving layer 16 are not particularly required.

  The fine unevenness forming layer 33 is a transparent layer having a light transmittance higher than that of the peeling protection layer 32, and is formed of, for example, a resin such as a photocurable resin, a thermosetting resin, or a thermoplastic resin. The width direction in the hologram ribbon 30 is the vertical direction in the image cell 20, and the longitudinal direction in the hologram ribbon 30 is the horizontal direction in the image cell 20. The fine unevenness forming layer 33 is a hologram element having a relief structure on the surface as a diffraction grating. The relief structure repeats a grating pattern, which is a groove extending along the longitudinal direction of the hologram ribbon 30, in the width direction of the hologram ribbon 30.

  In the relief structure of the fine unevenness forming layer 33, the spatial frequency, which is the number of grating patterns per unit length, is the pitch between the grating patterns, and determines the wavelength at which the reinforcing points are reinforced at a fixed point. The fine unevenness forming layer 33 stores the wavelength of light constituting the face image by such spatial frequency. The relief structures with mutually different spatial frequencies reinforce the light of different colors at a fixed point.

  In the relief structure of the fine asperity forming layer 33, the extending direction of the lattice pattern determines the direction in which the mutually constructive interference is viewed. The fine unevenness forming layer 33 stores the phase of the light constituting the face image by the extending direction of the lattice pattern. In relief structures in which the directions of extension of the grid pattern are different from each other, interferences that are mutually constructive are viewed from different directions.

  In the relief structure of the fine unevenness forming layer 33, the depth of the lattice pattern determines the amount of light taken into the lattice pattern. The fine unevenness forming layer 33 stores the amplitude of the light constituting the face image by the depth of the lattice pattern. In relief structures in which the depths of the grating patterns are different from each other, the degree of interference mutually enhancing is different from each other.

The transparent reflection layer 34 is, for example, a transparent layer having a refractive index different from that of the micro-relief forming layer 33, and is formed by, for example, a vacuum film formation method such as vacuum evaporation or sputtering. The transparent reflective layer 34 has a function of enhancing the visibility of the face image, but such transparent reflective layer 34 may be omitted if the application does not require any particular visibility of the face image. The transparent reflective layer 34 may have a single-layer structure or a multilayer structure. When the transparent reflective layer 34 has a multilayer structure, the transparent reflective layer 34 may be configured to repeat reflection interference inside the transparent reflective layer 34. As a transparent material for forming the transparent reflective layer 34, for example, a transparent dielectric such as ZnS or TiO ₂ can be used. In addition, as the transparent reflective layer 34, a metal layer having a thickness of less than 20 nm may be used. As a forming material of a metal layer, chromium, nickel, aluminum, iron, titanium, silver, gold, copper etc. can be used, for example.

  The adhesive layer 35 is for adhering the transparent reflective layer 34 to the surface of the transfer receiving body 45, and is formed on the surfaces of the fine asperity layer 33 and the transparent reflective layer 34. Examples of the material of the adhesive layer 35 include thermoplastic resins such as polypropylene resin, polyethylene terephthalate resin, polyacetal resin, polyester resin and the like, and inorganic fine particles are added to these resins. As the inorganic fine particles to be added, for example, silica or the like is used, and such inorganic fine particles are preferably added at a solid content ratio of 10 to 50 with respect to the solvent. Moreover, as for the layer thickness of the contact bonding layer 35, 0.2 micrometer or more and 1.0 micrometer or less are preferable. Since the hologram ribbon 30 is transferred in the form of a dot of a minute area or a line shape of a minute width, a foil cutting property is required. In the case of the adhesive layer 35 to which the inorganic fine particles are added, such foil cutting properties are good.

  As shown in FIG. 7, in the hologram ribbon 30, the fine asperity forming layer 33 is composed of a plurality of fine asperity forming portions H, and the plurality of fine asperity forming portions H are a first asperity forming portion H1, a second asperity forming portion H1. And a third micro-roughness forming portion H3. The first minute unevenness forming portion H1, the second minute unevenness forming portion H2, and the third minute unevenness forming portion H3 are repeated in order along the longitudinal direction of the hologram ribbon 30.

  Each of the plurality of fine concavo-convex forming portions H has a plurality of grating patterns extending along the longitudinal direction of the hologram ribbon 30, and the plurality of grating patterns are arranged along the width direction of the hologram ribbon 30. The first fine asperity forming portion H1 is a fine asperity forming portion H for forming the first image cell 20a, and the second asperity forming portion H2 is as for forming the second image cell 20b. The third unevenness forming portion H3 is the minute unevenness forming portion H, and the third unevenness forming portion H3 is the minute unevenness forming portion H for forming the third image cell 20c.

  In FIG. 7, the upper end in the width direction of the hologram ribbon 30 corresponds to the upper end in the first image display unit 12, and the lower end in the width direction of the hologram ribbon 30 corresponds to the lower end in the first image display unit 12.

  The configuration of the fine unevenness forming portion H will be described with reference to FIGS. 8 and 9. The second fine asperity forming portion H2 and the third fine asperity forming portion H3 are different from the first asperity forming portion H1 in the color of light to be visually recognized by the second fine asperity forming portion H2. Is the same as that of the first minute unevenness forming portion H1. That is, the first micro-roughness forming portion H1 is configured such that, when the first micro-roughness forming portion H1 is viewed from the fixed point, the same color, for example, red, is visually recognized in the vertical direction. The second fine unevenness forming portion H2 is configured such that, when the second fine unevenness forming portion H2 is viewed from a fixed point, the same color, for example, green, is visually recognized in the vertical direction. The third fine unevenness forming portion H3 is configured such that, when the third fine unevenness forming portion H3 is viewed from a fixed point, the same color, for example, blue, is visually recognized in the vertical direction.

  Therefore, in the following, the configuration of the first micro unevenness forming portion H1 will be described, and the second micro unevenness forming portion H2 and the third micro unevenness forming portion H3 The different parts are mainly described. First, the relationship between the wavelength of light condensed to a fixed point and the spatial frequency will be described with reference to FIG. 8, and then, with reference to FIGS. 9 (a) and 9 (b), the first micro unevenness forming portion H1. The structure of

  As shown in FIG. 8, the surface of the first micro-roughness forming portion H1 is shown as a virtual plane, and a reference point 41 which is a virtual point is determined on the surface of the first micro-roughness forming portion H1. ing. A straight line extending longitudinally along the reference point 41 is a reference line 42. The direction perpendicular to the longitudinal direction and the lateral direction, that is, the direction in which the normal to the surface of the first micro uneven portion H1 extends is the normal direction.

  Further, the observation distance ω is the distance between the reference point 41 and the fixed point 40. The incident angle α is the incident angle of the illumination light with respect to the observation angle. The diffraction angle β is a diffraction angle of diffracted light that makes the counterclockwise direction positive with respect to the observation angle. The diffraction angle β takes a positive value at each position above the reference point 41 and takes a negative value at each position below the reference point 41. Further, at each position on the reference line 42, the diffraction angle β increases in absolute value as the distance from the reference point 41 increases. The longitudinal distance γ is the distance from the reference point 41 to each position on the reference line 42.

  Here, the diffraction angle β, the longitudinal distance γ, and the observation distance ω at the first micro-roughness forming portion H1 satisfy the following formula (2), and the spatial frequency f at each position on the reference line 42, The wavelength λ of the light condensed to the fixed point 40 satisfies the following (3).

tan β = γ / ω (2)
f = (sin α-sin β) / λ (α> β) (3)
As equation (3) shows, when the incident angle α and the wavelength λ are fixed values, the spatial frequency f at each position on the reference line 42 depends on the diffraction angle β. The diffraction angle β continuously decreases from the upper end to the lower end on the reference line 42, takes positive values at each position above the reference point 41, and is negative at each position below the fixed point 40. It has a value. Therefore, when the incident angle α and the wavelength λ are fixed values, the spatial frequency f at each position on the reference line 42 decreases continuously from the upper end to the lower end.

  As shown in FIGS. 9 (a) and 9 (b), the first micro-roughness forming portion H1 has a pattern in which the lattice pattern extending along the horizontal direction is repeated in the longitudinal direction, and the distance between the lattice patterns is , Continuously decreasing from the upper end to the lower end. That is, the spatial frequency f of the first micro-roughness forming portion H1 decreases as the distance from the upper end increases, and continuously decreases from the upper end to the lower end. Then, the first micro-roughness forming portion H1 has a spatial frequency f which continuously decreases from the upper end to the lower end so that the wavelength λ in the equation (3) is the wavelength of red light. There is. In such a configuration, when the incident angle α is a fixed value, the light collected at the fixed point 40 is red. The wavelength of red light may be, for example, the wavelength of light having a single wavelength, or may be the wavelength having the highest intensity in light having a wavelength having a certain range, or constant The central wavelength may be, for example, 650 nm in the intensity spectrum of light having a wavelength in the range of

  Similarly, the second micro-roughness forming portion H2 has a spatial frequency f which decreases continuously from the upper end to the lower end, as the wavelength λ in Expression (3) is the wavelength of green light. ing. The wavelength of green light may be, for example, the wavelength of light having a single wavelength, or may be the wavelength having the highest intensity in light having a wavelength having a certain range, or constant The central wavelength may be, for example, 550 nm in the intensity spectrum of light having a wavelength in the range of

  The third micro-roughness forming portion H3 has a spatial frequency f which decreases continuously from the upper end to the lower end, such that the wavelength λ in the equation (3) is a wavelength of blue light. The wavelength of blue light may be, for example, the wavelength of light having a single wavelength, or may be the wavelength having the highest intensity in light having a wavelength having a certain range, or constant The center wavelength may be, for example, 450 nm in the intensity spectrum of light having a wavelength having a range of

An example of a pattern formation method using the hologram ribbon 30 will be described with reference to FIGS. 10 and 11.
In the formation of a pattern using the hologram ribbon 30, for example, first, image data for forming a face image of the owner is acquired. Next, a part of the hologram ribbon 30 is transferred to a part of the transfer target 45.

  As shown in FIG. 10A, the transfer receiving body 45 includes a base 46 and an image receiving layer 47 that covers the base 46. The substrate 46 is, for example, a paper material, a plastic substrate, a metal substrate, a ceramic substrate, a glass substrate or the like.

  When transferring the hologram ribbon 30, the hologram ribbon 30 is disposed on the transfer target 45 so that the adhesive layer 35 is in contact with the surface of the transfer target 45. From this state, thermal pressure 49 is applied, for example, by a thermal head in a range between the pair of dotted lines 48 on the upper surface of the support 31. As a result, the adhesive layer 35 adheres to the transfer receiving body 45 in the portion to which the heat pressure 49 is applied. Then, when the hologram ribbon 30 is peeled off from the transferred body 45, the support 31 is peeled off from the peeling protection layer 32 while the adhesive layer 35 is adhered to the transferred body 45 at the portion to which the heat pressure 49 is applied. Be

  As shown in FIG. 10B, only the transfer body 36 to which the thermal pressure 49 is applied in the hologram ribbon 30 is transferred onto the surface of the transfer target 45. Thus, each image cell 20 is formed by transferring the transfer body 36 to a predetermined position on the surface of the transfer receiving body 45.

  As shown in FIG. 11, the transfer of the transfer body 36 is repeated based on the image data for each of the fine asperities forming portions H1, H2 and H3 to form a pattern formed by the respective image cells 20a, 20b and 20c. The transfer medium 45 is formed. The respective image cells 20a aligned in the vertical direction, that is, the first image cell group, are formed of continuous portions along the vertical direction in one common fine concavo-convex forming portion H1. The respective image cells 20b arranged in the longitudinal direction, that is, the second image cell group, are formed of continuous portions along the longitudinal direction in one common fine concavo-convex forming portion H2. The respective image cells 20c aligned in the longitudinal direction, that is, the third image cell group are formed of continuous portions along the longitudinal direction in one common fine unevenness forming portion H3.

  As a result, since the spatial frequency f of the fine unevenness forming portion H1 satisfies the above equation (3) in the vertical direction, the spatial frequency f of the first image cell group also satisfies the above equation (3) in the vertical direction. In the first image cell group obtained in this manner, the spatial frequency f decreases as the distance from the upper end increases, so that the wavelength λ in Expression (3) is the wavelength of red light. Further, in the portion of the first image cell group in which the first image cell 20a is continuous along the vertical direction, the upper end of the portion is such that the wavelength λ in Equation (3) is the wavelength of red light. The spatial frequency f decreases continuously from the lower part to the lower part.

  Further, since the spatial frequency f of the fine unevenness forming portion H2 satisfies the above equation (3) in the vertical direction, the spatial frequency f of the second image cell group also satisfies the above equation (3) in the vertical direction. In the second image cell group obtained in this manner, the spatial frequency f decreases as the distance from the upper end increases, so that the wavelength λ in Equation (3) is the wavelength of green light. Further, in the portion of the second image cell group in which the second image cell 20b is continuous along the vertical direction, the upper end of the portion is such that the wavelength λ in Equation (3) is the wavelength of green light. The spatial frequency f decreases continuously from the lower part to the lower part.

  Further, since the spatial frequency f of the fine unevenness forming portion H3 satisfies the above equation (3) in the vertical direction, the spatial frequency f of the third image cell group also satisfies the above equation (3) in the vertical direction. In the third image cell group obtained in this manner, the spatial frequency f decreases as the distance from the upper end increases, so that the wavelength λ in Equation (3) is the wavelength of blue light. Further, in a portion of the third image cell group in which the third image cell 20c is continuous along the vertical direction, the upper end of the portion is such that the wavelength λ in Equation (3) is the wavelength of red light. The spatial frequency f decreases continuously from the lower part to the lower part.

The transfer range of the hologram ribbon 30 transferred by the thermal head will be described with reference to FIGS. 12 and 13.
As shown in FIG. 12, the transfer device 50 for transferring the hologram ribbon 30 to the transfer target 45 includes the transfer roll 51 and the thermal head 52 facing each other. The transfer device 50 is a ribbon transfer mechanism 53 for transferring the hologram ribbon 30 in the space between the transfer roll 51 and the thermal head 52, and a space between the transfer roll 51 and the thermal head 52, The transfer body transfer mechanism 54 for transferring the transfer body 45 in the space on the transfer roll 51 side is also provided. The transfer device 50 drives each of the transfer roller 51, the thermal head 52, the ribbon transfer mechanism 53, and the transfer member transfer mechanism 54 based on the image data to thereby form the fine unevenness forming portions H1, H1 on the transfer member 45. A part of H2 and H3 is transferred in order, and a pattern composed of each of the image cells 20a, 20b and 20c is formed on the transferred object 45.

  As shown in FIG. 13, the fine unevenness forming portions H 1, H 2 and H 3 have an outer shape larger than the outer shape of the first image display portion 12 in the longitudinal direction and width direction of the hologram ribbon 30. For example, in the case of the first image display unit 12 described above, the outer shape of the first image display unit 12 is larger by 10 mm or more and 100 mm or less.

  According to such a configuration, when attaching the hologram ribbon 30 to the ribbon transfer mechanism 53 or attaching the transfer target 45 to the transfer target transfer mechanism 54, the relative position between the hologram ribbon 30 and the transfer target 45 can be obtained. Even if misregistration occurs, it is possible to prevent the transfer from becoming impossible due to the misregistration.

  For example, from the reference transfer ranges A1s, A2s, and A3s, which are transfer ranges when there is no positional deviation between the transfer target 45 and the hologram ribbon 30, relative fine transfer patterns A1, A2, and A3 are formed on the fine unevenness forming portions H1, H2. It is assumed that the transfer range of H2 and H3 is shifted. Even in such a case, in each of the fine concavo-convex forming portions H1, H2 and H3, the light of a specific wavelength is condensed at the fixed point 40 so that the above equations (1) and (2) are satisfied. Since the spatial frequency is set, the position of the fixed point 40 with respect to each transfer range does not significantly shift as long as a part of each of the fine unevenness forming portions H1, H2 and H3 is the transfer range.

  In addition, a shift occurs in the feed amount in the hologram ribbon 30 attached to the ribbon transfer mechanism 53, and the relative position between the transfer target 45 and the hologram ribbon 30 along the longitudinal direction of the hologram ribbon 30 along with the shift of the feed amount. It is assumed that misalignment occurs in Even in such a case, since the spatial frequency of each of the fine unevenness forming portions H1, H2 and H3 is set in the vertical direction, that is, based on the width direction of the hologram ribbon 30, the positional deviation in the longitudinal direction is fixed point Does not affect the deviation of 40.

  In addition, in order to obtain an accurate color expression at the fixed point 40, color correction is required not only in the vertical direction but also in the horizontal direction. In the case of performing color correction in the lateral direction, it is necessary to change the diffraction grating so that the extending direction of the grating pattern changes continuously in the diffraction grating so that the ribbon transport mechanism 53 does not shift the feed amount. . On the other hand, since positional deviation of the hologram ribbon 30 is likely to occur in the longitudinal direction of the hologram ribbon 30, color correction in the lateral direction is not color change of the fine unevenness forming portions H1, H2 and H3 but image processing to correct color. It is desirable to be done. By correcting the color correction in the vertical direction with the spatial frequency of the micro-asperity forming portion H2 and further performing the color correction in the horizontal direction by image processing, a shift of the feed amount of the hologram ribbon 30 at the time of transfer occurs. Also, it is possible to display an image in which color shift does not occur and in which the color shift does not occur at the fixed point 40 in the upper, lower, left, and right.

  FIG. 14 (a) shows an observation image 56 which is an example of a face image generated by the first image display unit 12, and FIG. 14 (b) is different from the first image display unit 12 in spatial frequency in the vertical direction An observation image 57, which is an example of a face image generated by the image display unit in which f is uniform, is shown.

  As shown in FIG. 14, in the case of observing the first image display unit 12 from one direction, the observation image 56 focuses light of a specific wavelength to the fixed point 40 in each of the image cells 20a, 20b, and 20c. For example, the color of the skin does not differ significantly from the forehead of the face image to the chin. On the other hand, in the observation image 57, since each image cell does not condense light of a specific wavelength at the fixed point 40, even if the image display unit is observed from one direction, the color tone of the skin from the forehead of the face image to the chin Will be significantly different. In addition, when the marks 58 and 59 with designated color arrangement are included at the upper end and the lower end of the observation image 56, the marks 58 and 59 of the observation image 56 are visually recognized in the same color at the fixed point 40 58 and 59 are not viewed in the same color at the fixed point 40. By visually observing the color of the face image and the color of the mark, it is easy to determine the authenticity of the first image display unit 12 and, in turn, the presence or absence of an illegal act on the passport 10.

[Example]
The hologram ribbon 30 was formed as follows. First, a polyethylene terephthalate film with a thickness of 12 μm was used as the support 31. The release protective layer 32 and the thermoplastic resin layer were formed in this order on the support 31 using a gravure coater, and these were dried in an oven. An acrylic resin was used as the material of the peeling protective layer 32, and an acrylic polyol was used as the material of the thermoplastic resin layer. The film thickness of the peeling protective layer 32 after drying was 0.6 μm, and the film thickness of the thermoplastic resin layer after drying was 0.7 μm.

  Next, the fine concavo-convex portions H1, H2, H3 as holograms were formed on the surface of the thermoplastic resin layer by heat press using a roll embossing device. The size of each of the fine unevenness forming portions H1, H2 and H3 is 50 mm × 50 mm, and the depth is about 100 nm. The spatial frequency f of the first micro-roughness forming portion H1 is 1020 lines / mm or more and 1275 lines / mm or less, and the spatial frequency f of the second micro-roughness forming portion H2 is 1205 lines / mm or more and 1505 / mm Hereinafter, the spatial frequency f of the third micro-roughness forming portion H3 is 1470 / mm or more and 1840 / mm or less. These spatial frequencies f are continuously changed so that the value becomes higher toward the lower side. The spatial frequency f of the first fine unevenness forming portion H1 is based on the wavelength λ = 650 nm of red light, and the spatial frequency f of the second fine unevenness forming portion H2 is the wavelength λ of green light The spatial frequency f of the third micro-roughness forming portion H3 is based on the wavelength λ = 450 nm of blue light.

  Next, a transparent reflective layer 34 made of zinc sulfide was formed on the fine asperity layer 33 by vapor deposition. The film thickness of the transparent reflective layer 34 was 50 nm. Further, the adhesive layer 35 was formed by printing a polyester resin which is a thermoplastic resin on the transparent reflective layer 34. The film thickness of the adhesive layer 35 was 0.6 μm.

The first image display unit 12 was formed by the following method using the hologram ribbon 30 described above.
First, a plastic card was used as the base 46 of the transfer target 45. An image receiving layer 47 was formed on a substrate 46 using a gravure coater and dried in an oven. As a material of the image receiving layer 47, an acrylic polyol was used. The film thickness after drying of the image receiving layer 47 was 2.0 μm.

  Next, based on the image data on which image processing has been performed so that a face image can be displayed in three colors of R, G, and B, thermal transfer using a thermal head of 300 dpi is performed from the support 31 to the image receiving layer 47. The image cells 20a, 20b and 20c were transferred to the top.

  In the transfer of each image cell 20a, 20b, 20c, first, the first minute unevenness forming portion H1 of the hologram ribbon 30 is disposed in the space between the transfer roll 51 and the thermal head 52 to The image cell 20a is printed in a dot shape or a linear shape at the position corresponding to red in the above. Next, the second micro-roughness forming unit H2 is transferred to the space between the transfer roll 51 and the thermal head 52, and the image cell 20b has a dot shape or the position corresponding to green in the image data. , Printed in linear form. Then, the third micro-roughness forming portion H3 is transferred to the space between the transfer roll 51 and the thermal head 52, and the image cell 20c has a dot shape or the position corresponding to blue in the image data. It printed in a line shape. Note that the printing area, which is the area of each image cell 20, is such that the image cell 20 adjacent to each other in the lateral direction does not overlap with each other, and has a maximum size and half the size thereof. There are two in total. As described above, the first image display unit 12 of the embodiment is obtained.

[Comparative example]
In the comparative example, the first image display unit 12 is formed by using the hologram ribbon 30 having the same structure as the hologram ribbon 30 of the example as a basic structure but the spatial frequency f of the fine asperity forming portion is different from that of the example. In the comparative example, the spatial frequency f of the first micro uneven portion H1 is 1150 lines / mm, the spatial frequency f of the second micro uneven portion H2 is 1350 lines / mm, and the third micro uneven portion is formed. The spatial frequency f of the part H3 is 1650 lines / mm. That is, the spatial frequency f is uniform in each of the fine unevenness forming portions H1, H2, H3.

  The first micro-roughness forming portion H1 is for red light, the second micro-roughness forming portion H2 is for green light, and the third micro-roughness forming portion H3 is for blue light. Then, using the hologram ribbon of the comparative example, the first image display unit 12 was formed on the material to be transferred 45 with the same image data as that of the example. The first image display unit 12 of the comparative example was obtained as described above.

  The first image display unit 12 of the embodiment and the first image display unit 12 of the comparative example are illuminated with illumination light having an incident angle of 40 °, and are separated from the first image display unit 12 by 30 cm. From the place, the image displayed by the first image display unit 12 was observed. As a result, in the first image display unit 12 of the embodiment, the color of the skin of the face image does not differ between the upper end and the lower end, and the color of the skin of the face image is visually recognized in the same color. On the other hand, in the first image display unit 12 of the comparative example, the center of the face image showed a skin color, but each of the upper end and the lower end was viewed in a color out of the skin color.

As mentioned above, according to the said embodiment, the effect listed below is acquired.
(1) When the first image display unit 12 is viewed visually from the fixed point 40, the first image cell group indicates red, the second image cell group indicates green, and the third image cell group indicates blue. . Whether the face image displayed on the first image display unit 12 is true or false can be determined depending on whether or not this observation result is obtained. As a result, it becomes easy to determine the authenticity of the first image display unit 12 by visual inspection of the collator.

  (2) Since the image cells 20a, 20b, and 20c have different design wavelengths, the image observed at the fixed point 40 can be colored or full color. As a result, the degree of freedom of the image that can be displayed by the first image display unit 12 is expanded, and the authenticity of the image displayed by the first image display unit 12 can be more easily determined.

(3) Since the image cells 20a, 20b, and 20c are selectively stacked, the image displayed by the first image display unit 12 becomes finer.
(4) Since the first image display unit 12 and the second image display unit 13 are arranged in one sheet, the image displayed by the first image display unit 12 and the image displayed by the second image display unit 13 Comparison is easy, and the accuracy of the comparison result is also enhanced.

  (5) Since the area of the first image display unit 12 is 0.25 times or more and twice or less the area of the second image display unit 13, the image displayed by the first image display unit 12 and the second image The comparison with the image displayed on the display unit 13 is not difficult, and the decrease in the accuracy of the personal identification can be suppressed.

  (6) The lattice pattern of each of the fine unevenness forming portions H1, H2 and H3 is formed along the longitudinal direction of the hologram ribbon 30, which is the transfer direction of the hologram ribbon 30. Therefore, even if positional deviation occurs in the transfer direction of the hologram ribbon 30 at the time of transfer of the image cells 20a, 20b, and 20c, the position of the fixed point 40 with respect to each of the image cells 20a, 20b, and 20c hardly deviates significantly.

In addition, the said embodiment can also be changed suitably as follows and can also be implemented.
-The passport 10 should just be equipped with the 1st image display part 12, for example, the 1st image display part 12 and the 2nd image display part 13 may be provided in another paper surface, or the 2nd image The display unit 13 may be omitted.

-In order to colorize the image displayed by the first image display unit 12, the image cells 20a, 20b, and 20c may be simply arranged along one plane without being stacked.
-The image which the 1st image display part 12 displays does not need to be a color, for example, the 1st image display part 12 may be comprised only from the image cell 20 corresponding to a single color.

  -One image cell group may have a configuration including a portion where the spatial frequency f is smaller as the distance from one end of the image cell group is larger in the direction orthogonal to the extending direction of the grid pattern, one end of the image cell group The part from which the spatial frequency f is large may be included as the distance from the part is large, and the part from which the spatial frequency f is constant may be included.

  Also, in the portion where the spatial frequency f is smaller as the distance from one end of the image cell group is larger, for example, one image cell group is from the one end of the image cell group in the direction orthogonal to the extending direction of the grid pattern. The spatial frequency f may be smaller as the image cell 20 has a larger distance. Also, for example, in one image cell group, a predetermined number of image cells 20 aligned with each other in the direction orthogonal to the extending direction of the grid pattern is one image cell block, and the direction orthogonal to the extending direction of the grid pattern In the image cell block, the spatial frequency f may be smaller as the distance from the one end of the image cell group is larger. Furthermore, the spatial frequency f in one image cell group may be a combination of two or more forms arbitrarily selected from these forms.

  -With reference to FIG.15 and FIG.16, the modification about the formation method of the image display device with respect to a sheet | seat is demonstrated. In the method described below, after the plurality of image cells are formed on the first transfer body, the image display devices are formed on the sheet by transferring the plurality of image cells to the sheet as the second transfer body. Be done.

  As FIG. 15 shows, the 1st to-be-transferred body 61 has the laminated structure which the base material 62, the peeling protective layer 63, the image receiving layer 64, and these were laminated | stacked one by one. The second transfer receiving body 65 has a laminated structure in which a base 66, an image receiving layer 67, and these are sequentially laminated.

  In the first transferred body 61, the base 62 is, for example, a resin film and a resin sheet including a flat resin thin plate having a surface thicker than the resin film and sufficiently wider than the thickness. For example, it is formed of a heat-resistant material such as polyethylene terephthalate. The peeling protective layer 63 is laminated on the base 62. The release protective layer 63 serves to stabilize the release from the base material 62 and to promote the adhesion of the image cells 20 a, 20 b and 20 c to the image receiving layer 67 of the second transfer receiving body 65. The exfoliation protective layer 63 is light transmissive and is typically transparent. The image receiving layer 64 enhances the adhesion between the substrate 62 and the plurality of image cells 20a, 20b, 20c.

  In the second transferred body 65, the base 66 is, for example, a resin film and a resin sheet including a flat resin thin plate having a surface thicker than the resin film and sufficiently wider than the thickness. For example, it is formed of a heat-resistant material such as polyethylene terephthalate. The image receiving layer 67 exhibits a function of enhancing the adhesion between the substrate 66 and the plurality of image cells 20a, 20b, 20c. Then, after the image cells 20a, 20b, and 20c are formed on the first transferee body 61, the image cells 20a, 20b, and 20c are in contact with the image receiving layer 16 of the second transferee body 65. Pressure 68 is applied.

  As shown in FIG. 16, when the base 46 of the first transferred body 61 is peeled off, the laminate other than the base 62 of the first transferred body 61 is transferred to the second transferred body 65 as a transfer body. Ru. The thermal transfer may be thermal transfer using a heat roll or a thermal head, in addition to thermal transfer using a pot stamp.

  After the laminate is thermally transferred to the second transfer receiving body 65 as described above, necessary steps are appropriately performed. Even with such a method, the first image display unit 12 can be obtained. In such a method, the image cells 20a, 20b, and 20c are formed on the first transfer target body 61, so the surface roughness of the sheet 11 and the like hardly affect the image quality.

The sheet 11 may be other than paper, and may be, for example, a plastic substrate, a metal substrate, a ceramic substrate, or a glass substrate.
The image displayed by the image display device may include other biometric information in addition to the face image, or may include other biometric information instead of the face image. Further, the image displayed by the image display device may include at least one of non-living personal information and non-personal information in addition to the living body information, and non-living personal information and non-personal information instead of living information. Or at least one of the above.

The image displayed by the image display device is not limited to the owner's face image, and may be, for example, letters, numbers, symbols, figures, patterns, or a combination of these.
The method of forming the image cell 20 is not limited to the transfer of the micro-asperity forming layer 33, and the image cell 20 may be formed directly on the sheet 11.

  The image display medium is not limited to the passport 10. For example, credit cards, driver's licenses, employee identification cards, identification cards such as membership cards, entrance examination admission tickets, passports, etc., banknotes, gift certificates, point cards, It may be a stock certificate, a security ticket, a betting ticket, a passbook, a ticket, a passage ticket, an airline ticket, an admission ticket for various events, a game ticket, a prepaid card for transportation or a public telephone, and the like.

A1, A2, A3: Transfer range, H: Fine unevenness forming portion, A1s, A2s, A3s: Reference transfer range, 10: Passport, 11: Sheet, 12: First image display portion, 13: Second image display portion, 15: paper material, 16: image receiving layer, 16a: surface, 16b: square lattice, 16c: lattice point, 20: image cell, 30: hologram ribbon, 31: support, 31a: peeling surface, 32: peeling protective layer, 33: fine unevenness forming layer 34: transparent reflective layer 35: adhesive layer 36: transfer body 40: fixed point 41: reference point 42: reference line 45: transferred body 46: base material 47 Image receiving layer 48: dotted line 49: heat pressure 50: transfer device 51: transfer roll 52: thermal head 53: ribbon transfer mechanism 54: transfer target body transfer mechanism 56: observation image 57: observation image , 58, 59 ... mark, 61 ... first driven Body, 62 ... base, 63 ... peeling protective layer, 64 ... image receiving layer, 65 ... second transfer object, 66 ... base, 67 ... image receiving layer, 68 ... hot pressing.

Claims (11)

A plurality of image cells having a hologram layer and arranged in a two-dimensional manner, wherein the hologram layer extends a first-dimensional grating pattern extending along a first direction along a second direction orthogonal to the first direction An image display device comprising a repeating diffraction grating,
The plurality of image cells arranged along the second direction and associated with one color are one image cell group,
The image cell groups, in a state where the viewpoint in a predetermined direction with respect to the image display device is located, such that each of the plurality of the image cells forming the image cell group to display the same color to each other, the second square saw including a spatial frequency smaller portion of the diffraction grating larger the distance from one end of the image cell groups in countercurrent,
The image display device includes an image display unit configured of a plurality of the image cells and displaying an image.
An image display device , wherein a horizontal direction of the image is the first direction, and a vertical direction of the image is the second direction . The image cell group is
In a state in which the viewpoint is located in the predetermined direction with respect to the image display device, each of a plurality of the image cells constituting the image cell group is associated with the first color so as to display a first color A first image cell group composed of the plurality of the image cells,
The plurality of image cells arranged along the second direction and associated with a second color are a second image cell group,
In the second image cell group, each of a plurality of image cells constituting the second image cell group displays the second color in a state in which the viewpoint is located in the predetermined direction with respect to the image display device. to as described above, the image display device according to claim 1 including the spatial frequency is small portion of the more the diffraction grating is greater distance from the second way one end of the second image set of cells at direction. The plurality of image cells arranged along the second direction and associated with the third color are a third image cell group.
In the third image cell group, each of a plurality of image cells constituting the third image cell group displays the third color in a state where the viewpoint is located in the predetermined direction with respect to the image display device. to as described above, the image display device according to claim 2 including the third one as the spatial frequency is smaller portions of the diffraction grating is greater distance from the end of the image cell groups in the second way direction. Each of all the image cells arranged along the second direction belongs to any one of the first image cell group, the second image cell group, and the third image cell group. Item 3. The image display device according to item 3. The image display device according to any one of claims 1 to 4, wherein a plurality of the image cells include portions overlapping each other. A plurality of image cells having a hologram layer and arranged in a two-dimensional manner, wherein the hologram layer extends a first-dimensional grating pattern extending along a first direction along a second direction orthogonal to the first direction An image display device comprising a repeating diffraction grating,
The plurality of image cells arranged along the second direction and associated with one color are one image cell group,
The image cell group is configured such that each of a plurality of the image cells forming one image cell group displays the same color with each other in a state in which the viewpoint is positioned in a predetermined direction with respect to the image display device. The spatial frequency f of the diffraction grating in the image cell group and the wavelength λ of the light of one color satisfy the following formula (1): f = (sin α−sin β) / λ (α> β).・ (1)
The incident angle α is an incident angle of the illumination light to the image display device,
The diffraction angle beta, Ri diffraction angle der of the diffracted light passing through the viewpoint in the diffracted light in the grating pattern,
The image display device includes an image display unit configured of a plurality of the image cells and displaying an image.
An image display device , wherein a horizontal direction of the image is the first direction, and a vertical direction of the image is the second direction . An image display medium comprising an image display device for displaying an owner's face image, comprising:
The image display device is the image display device according to any one of claims 1 to 6. Image display medium. The image display device is a first image display unit,
The image display medium according to claim 7, further comprising a second image display unit which is a printing unit that expresses the face image of the owner by the wavelength of light and the amplitude of light. 9. The image display medium according to claim 8, wherein the area of the first image display unit is not less than 0.25 times and not more than 2 times the area of the second image display unit.   A hologram ribbon used to manufacture the image display device according to any one of claims 1 to 5,
  The micro-relief forming portion includes a diffraction grating that repeats a one-dimensional grating pattern extending along the longitudinal direction of the hologram ribbon along a width direction orthogonal to the longitudinal direction.
  The fine asperity forming portion is one end of the asperity forming portion in the width direction such that the fine asperity forming portion displays one color in a state where the viewpoint is positioned in a predetermined direction with respect to the hologram ribbon. Including a portion where the spatial frequency of the diffraction grating is smaller as the distance from the portion is larger,
  The longitudinal direction is a transport direction of the hologram ribbon,
  The lateral direction of the image displayed by the image display device is the longitudinal direction, and the longitudinal direction of the image is the width direction
  Hologram ribbon characterized by   A hologram ribbon used for manufacturing the image display device according to claim 6,
  The micro-relief forming portion includes a diffraction grating that repeats a one-dimensional grating pattern extending along the longitudinal direction of the hologram ribbon along a width direction orthogonal to the longitudinal direction.
  The fine asperity forming portion has a spatial frequency f of the diffraction grating in the width direction such that the fine asperity forming portion displays one color in a state where the viewpoint is positioned in a predetermined direction with respect to the hologram ribbon. The wavelength λ of the light of one color has a portion satisfying the following formula (1)
  f = (sin α-sin β) / λ (α> β) (1)
  The incident angle α is an incident angle of the illumination light to the image display device,
  The diffraction angle β is a diffraction angle of diffracted light passing through the viewpoint in diffracted light in the grating pattern,
  The longitudinal direction is a transport direction of the hologram ribbon,
  The lateral direction of the image displayed by the image display device is the longitudinal direction, and the longitudinal direction of the image is the width direction
  Hologram ribbon characterized by