JPWO2019070081A1 - Hologram element, information recording medium, label body, transfer foil body, card, hologram sheet and hologram duplication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separately observe a Fourier transform hologram reproduction image and a volume reflection type hologram reproduction image. SOLUTION: The hologram element has a first interference fringe that is converted into a Fourier transformed hologram reproduced image when light from a point light source arranged apart from the incident surface is incident, and a normal direction of the incident surface. The hologram layer is provided with a second interference fringe that is converted into a volumetric reflection type hologram reproduction image when the reproduction illumination light is incident on the incident surface along a direction inclined with respect to the above.

Description

The present disclosure relates to a hologram element, an information recording medium, a label body, a transfer foil body, a card, a hologram sheet, and a hologram duplication method.

Volumetric reflection holograms, also called Lipman holograms, have less color dispersion because they select and diffract light of a specific wavelength when light with a specific incident angle is incident, and interference fringes are created by the image hologram method. By recording, a three-dimensional image with little blur can be observed even in various light source environments, so it is widely used for the purpose of preventing counterfeiting. In addition, phase-type Fourier transform holograms using computer-synthesized hologram technology and imprint technology are widely used for anti-counterfeiting purposes because they can be mass-produced at low cost (Japanese Patent Laid-Open No. 2017-37772). Issue).

Further, a method of recording a Fourier transform hologram on a recording medium for recording the above-mentioned Lippmann hologram (hereinafter, Lippmann hologram recording medium) is known (Japanese Unexamined Patent Publication No. 2009-139676). In this type of technique, as shown in FIG. 13, the original image 76 of the Fourier transformed hologram is placed at the front focal point of the optical lens 75, and the Lipman hologram recording medium 77 is placed at the rear focal point of the optical lens 75. Interference fringes between the reference light and the object light generated from the original image 76 of the Fourier transformed hologram are recorded on the Lipman hologram recording medium 77.

The spread angle θ of the Fourier transform hologram reproduced image reproduced by irradiating the recording medium 77 recorded by the method as shown in FIG. 13 with the reproduction illumination light is incident on the optical lens 75 from the original image 76 of the Fourier transform hologram at the time of recording. It is about the same as the maximum angle θmax with respect to the optical axis of the light beam. The larger the effective aperture of the lens and the shorter the focal length, the larger the maximum angle θmax of the optical lens 75.

The focal length f of the thin-walled single lens 78 shown in FIG. 14 is expressed by the following equation (1) when the radius of curvature r1 on the front surface of the lens, the radius of curvature r2 on the rear surface of the lens and the refractive index n are used.

When the plane side of the plano-convex lens is arranged on the front surface of the lens, r1 is infinite, so it is approximated by Eq. (2).

In the case of BK7, which is often used in optical glass, the refractive index n of light having a wavelength of 532 nm is n = 1.519, and the maximum angle θmax in a plano-convex lens is represented by sin θmax = 1 / 2F. Here, F is the F value of the lens, and is represented by F = f / D, where D is the effective aperture of the lens. From the above conditions and equations, θmax≈31.26 ° is calculated. This is the case of a lens having an effective aperture D = 2r, and in reality, it is difficult to realize the maximum angle θmax up to this point in order to avoid the influence of lens aberrations and the like. As an example, when an interference fringe is formed with a lens outer diameter of φ100 mm and a focal length of 200 mm, the spread angle θ is about 5 to 10 °, and the design width is limited. In order to ensure visibility, the conventional Fourier transform hologram is premised on irradiating a laser beam during reproduction and projecting the reproduced image onto a screen installed on the incident side of the laser beam for observation. It needed extensive equipment.

Further, when duplicating a hologram from an original plate in which the interference fringes of the Fourier transform hologram and the interference fringes of the volume reflection hologram are formed, it is desirable to duplicate using the same reference light in consideration of manufacturing efficiency. When the hologram element duplicated with the same reference light is reproduced, the Fourier transform hologram reproduction image and the volume reflection type hologram reproduction image are reproduced in an overlapping manner, and both reproduced images cannot be separated, resulting in deterioration of visibility. For this reason, it is necessary to provide the Fourier transform hologram and the volume reflective hologram as separate recording areas in the hologram element, or to make the wavelength of the reference light different when recording, which makes it troublesome to manufacture the hologram element. It will take.

In the present disclosure, it is possible to improve the workability of duplication from the original plate in which the interference fringes of the Fourier transform hologram and the interference fringes of the volume reflection hologram are formed, and the Fourier transform hologram reproduction image and the volume reflection hologram reproduction image. Provided are a hologram element, an information recording medium, a label body, a transfer foil body, a card, and a hologram sheet that can be observed separately from the above.

[Means to solve problems]
In order to solve the above problem, according to one aspect of the present disclosure, when light from a point light source arranged apart from the incident surface is incident, it is converted into a Fourier transformed hologram reproduced image. The interference fringes and the second interference fringes that are converted into a volumetric reflection hologram reproduction image when the reproduction illumination light is incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface. A hologram element is provided that includes a hologram layer that is superimposed and recorded. Since the first interference fringe and the second interference fringe are formed on the same hologram layer, the Fourier transform reproduction image and the volume reflection type hologram reproduction image can be reproduced under the reproduction illumination light conditions suitable for each.

The incident direction of the reproduction illumination light and the reproduction direction of the volumetric reflection type hologram reproduction image may have different off-axis relationships from each other. Since the incident direction of the reproduction illumination light and the reproduction direction of the volume reflection type hologram reproduction image are different from each other, the volume reflection type hologram reproduction image can be observed without overlapping with the reproduction illumination light.

The Fourier transform hologram reproduction image is observed in the normal direction of the incident surface when the point light source is irradiated from the normal direction of the incident surface.
The volumetric reflection hologram reproduction image is observed in the normal direction of the incident surface when the regenerated illumination light is incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface. You may. The Fourier transform hologram reproduction image can be observed with the point light source, and the volume reflection type hologram reproduction image can be observed from a direction different from the incident direction with the reproduction illumination light different from the point light source.

The Fourier transform hologram reproduction image observed in the normal direction of the incident surface according to the incident angle of the reference light when the second interference fringe is recorded on the hologram layer with respect to the normal direction of the incident surface. The shade of may change. By changing the incident angle of the reference light when recording the second interference fringe, the hue of the Fourier transform hologram reproduced image can be changed.

As the incident angle of the reference light increases, the hue of the Fourier transform hologram reproduced image observed in the normal direction of the incident surface may change more significantly. If the incident angle of the reference light is made larger, the hue of the Fourier transform hologram reproduced image can be changed more greatly.

When the regenerated illumination light is incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface, the incident surface is observed along the specular reflection direction of the reflected light of the regenerated illumination light. Then, the hue of the Fourier transformed hologram reproduced image may change. When the incident surface is observed from the specular reflection direction opposite to the incident direction of the regenerated illumination light, the hue of the Fourier transform hologram reproduced image can be changed.

In another aspect of the present invention, a first interference fringe that is converted into a Fourier transformed hologram reproduced image when light from a point light source arranged apart from the incident surface is incident, and a method of the incident surface. A hologram layer recorded by superimposing a second interference fringe that is converted into a volumetric reflection hologram reproduction image when the reproduction illumination light is incident on the incident surface along a direction inclined with respect to the line direction. Prepare,
An information recording medium containing predetermined information is provided for at least one of the Fourier transform hologram reproduction image and the volume reflection type hologram reproduction image. Since the first interference fringe and the second interference fringe are formed on the same hologram layer, the Fourier transform reproduction image and the volume reflection type hologram reproduction image can be reproduced under the reproduction illumination light conditions suitable for each, and the Fourier transform Predetermined information can be included in at least one of the reproduced image and the volume reflection type hologram reproduced image.

In another aspect of the present disclosure, at least an adhesive layer, a hologram layer, and a protective film layer are sequentially laminated on a separator, and the hologram layer is incident with light from a point light source arranged apart from an incident surface. The first interference fringe, which is converted into a Fourier-transformed hologram reproduction image at the time, and the volume reflection when the reproduction illumination light is incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface. A label body is provided in which a second interference fringe converted into a type hologram reproduced image is superimposed and recorded. By attaching a label body having a hologram layer on which the first interference fringes and the second interference fringes are formed to various media, the Fourier transform reproduction image and the volume reflection type hologram reproduction image can be observed in various media. it can.

In another aspect of the present disclosure, at least the hologram layer, the release layer, and the base material layer are sequentially laminated on the heat seal layer, and the hologram layer emits light from a point light source that is arranged away from the incident surface. When the first interference fringe, which is converted into a Fourier transformed hologram reproduced image when incident, and the reproduced illumination light are incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface. Provided is a transfer foil body in which a second interference fringe converted into a volumetric reflection hologram reproduction image is superimposed and recorded. By transferring the transfer foil body provided with the hologram layer on which the first interference fringes and the second interference fringes are formed to various media, the Fourier transform reproduction image and the volume reflection type hologram reproduction image can be obtained in various media. Can be observed.

In another aspect of the present disclosure, at least a heat seal layer, a hologram layer, a protective film layer, and an oversheet are sequentially laminated on a card core sheet, and the hologram layer is arranged at a distance from an incident surface. The first interference fringe, which is converted into a Fourier-converted hologram reproduction image when the light from the light is incident, and the reproduction illumination light are incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface. The second interference fringe, which is converted into a volumetric reflection hologram reproduction image when it is made to flow, is superimposed and recorded.
A card is provided in which at least one of the Fourier transform hologram reproduction image and the volume reflection type hologram reproduction image contains predetermined information. Since the first interference fringe and the second interference fringe are formed on the hologram layer of the card, a card capable of observing the Fourier transform reproduction image and the volume reflection type hologram reproduction image under the reproduction illumination light conditions suitable for each can be obtained. ..

A laser printing layer that is arranged between the card core sheet and the heat seal layer and is altered by laser light of a predetermined frequency may be provided. Since not only the hologram layer but also the laser printing layer is provided on the card, not only the Fourier transform reproduction image and the volume reflection type hologram reproduction image can be observed, but also arbitrary information can be recorded on the laser printing layer.

The laser printing layer is arranged so as to cover the entire surface of the card core sheet.
The hologram layer may be arranged on a part of the laser printing layer. Since the laser printing layer is arranged so as to cover the entire surface of the card core sheet, arbitrary information can be recorded in a place that does not overlap with the hologram layer of the laser printing layer.

At least personal information may be recorded on the laser printing layer due to partial alteration by the laser light. By irradiating the laser printing layer with laser light, the laser printing layer can be altered such as discoloration, melting, carbonization, foaming, or coloring.

In another aspect of the present invention, at least the heat seal layer, the hologram layer, the protective film layer, and the oversheet are sequentially laminated on the base sheet, and the hologram layer is arranged apart from the incident surface. A first interference fringe that is converted into a Fourier-converted hologram reproduction image when light from a light source is incident, and a reproduction illumination light are applied to the incident surface along a direction inclined with respect to the normal direction of the incident surface. The second interference fringe, which is converted into a volumetric reflection hologram reproduction image when incident, is superimposed and recorded.
A hologram sheet is provided in which at least one of the Fourier transform hologram reproduction image and the volume reflection type hologram reproduction image contains predetermined information. Since the first interference fringe and the second interference fringe are formed on the hologram layer of the hologram sheet, the Fourier transform reproduction image and the volume reflection type hologram reproduction image can be observed by switching to each reproduction illumination light condition.

In another aspect of the present invention, a hologram recording member having a photosensitive material layer is arranged on an original plate on which a base material layer, a Fourier transform hologram layer, a reflection layer, an adhesive layer and a volume reflection type hologram layer are laminated. Then, reference light is incident on the upper surface of the hologram recording member along a direction inclined with respect to the normal direction of the upper surface of the hologram recording member.
A part of the reference light is transmitted through the hologram recording member, incident on the original plate, and diffracted by the volume reflective hologram layer to generate the first diffracted light.
The first diffracted light and the reference light interfere with each other in the photosensitive material layer in the hologram recording member to form a first interference fringe.
The remaining portion of the reference light passes through the volume reflective hologram layer and is diffracted on the surface of the Fourier transform hologram layer to generate a second diffracted light.
Provided is a hologram duplication method in which the second diffracted light and the reference light interfere with each other in the photosensitive material layer in the hologram recording member to form a second interference fringe. By irradiating the reference light with the hologram recording member placed on the original plate in which the Fourier transform hologram layer and the volume reflective hologram layer are laminated, the photosensitive material layer in the hologram recording member is subjected to the first interference fringes and the first interference fringes. Since the two interference fringes can be formed, holograms of uniform quality can be mass-produced at low cost.
[The invention's effect]

According to the present disclosure, it is possible to improve the workability of duplication from the original plate in which the interference fringes of the Fourier transform hologram and the interference fringes of the volume reflection hologram are formed, and the Fourier transform hologram reproduction image and the volume reflection hologram are reproduced. The reproduced image can be observed separately.

The cross-sectional view which shows the cross-sectional structure of the original plate for manufacturing the hologram element by this embodiment. The figure explaining the process of a two-step method. The figure explaining the process following FIG. 2A. The figure which shows the schematic structure of the duplication machine. A cross-sectional view of a hologram recording member arranged on the upper surface of the original plate. The figure which shows an example of the Fourier transform hologram reproduction image at the incident angle of 30 °. The figure which shows an example of the Fourier transform hologram reproduction image at the incident angle 40 °. The figure explaining the reproduction method of the Lippmann hologram reproduction image. The figure explaining the reproduction method of the Fourier transform hologram reproduction image. The xy chromaticity diagram which shows the evaluation result of the Fourier transform hologram reproduction image. The figure which shows the hologram element used for the evaluation of FIG. The figure which shows the measurement point of the Fourier transform hologram reproduction image used for the evaluation of FIG. FIG. 3 is a cross-sectional view of a label body provided with a hologram element according to the present embodiment. FIG. 3 is a cross-sectional view of a transfer foil body provided with a hologram element according to this embodiment. FIG. 3 is a cross-sectional view of a card embedded body provided with a hologram element according to this embodiment. Top view of the card. Sectional view of the card. Sectional drawing of the card which added the laser printing layer. The figure explaining the method of recording a Fourier transform hologram on a Lippmann hologram recording medium. The figure explaining the radius of curvature of a thin-walled single lens.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings attached to the present specification, the scale, aspect ratio, etc. may be appropriately changed from those of the actual drawings and exaggerated for the convenience of easy understanding of the drawings.

In addition, terms such as "parallel", "orthogonal", and "identical" that specify the shape and geometric conditions and their degrees as used in the present specification are not bound by strict meanings. The interpretation shall include the range in which similar functions can be expected.

Further, the "vertical direction" in the present specification is a direction non-parallel to the horizontal direction in a plane parallel to the vertical direction, and does not necessarily coincide with the vertical direction. "Upper" refers to one side (or one side) in the vertical direction closer to "upper" in the vertical direction. The "bottom" refers to the side opposite to the "top" in the vertical direction and the side (or direction) close to the "bottom" in the vertical direction.

Further, in the present specification, terms such as "sheet", "film", and "board" are not distinguished from each other based only on the difference in names. Thus, for example, "sheet" is a concept that includes members that can be called films or plates.

FIG. 1 is a cross-sectional view showing a cross-sectional structure of an original plate 2 for producing a hologram element according to the present embodiment. In the original plate 2 of FIG. 1, a glass layer 3, an adhesive layer 4, a base material layer 5, a surface relief type Fourier transform hologram layer 6, a reflection layer 7, a transparent adhesive layer 8, a Lipman hologram layer 9, and a cover glass 10 are laminated in this order. It was done.

The production of the surface relief type Fourier transform hologram layer 6 (hereinafter referred to as the Fourier transform hologram layer 6) and the production of the Lipman hologram layer 9 in the original plate 2 are performed separately, and after the production of these hologram layers is completed, these The hologram layer of FIG. 1 is adhered in the layer direction to prepare the original plate 2 of FIG.

The Fourier transform hologram layer 6 is produced by, for example, CGH (Computer-Generated Hologram). More specifically, the Fourier transform image from which the Fourier transform hologram layer 6 is formed is generated by performing a process such as Fourier transform on the original image using a computer, for example. Specifically, first, an original image is generated on a personal computer (PC). The original image is an arbitrary character, symbol, pattern, or the like. Next, the Fourier transform image is binarized. That is, the phase of each pixel of the Fourier transform image is examined, and when the phase is from minus 90 ° to plus 90 °, a predetermined value corresponding to transparency is assigned, and in other cases, black or a mirror surface is assigned. Binarization is performed by assigning another corresponding value. The phase range to which a predetermined value is assigned may be set outside the range of minus 90 ° to plus 90 °.

Next, the binarized Fourier transform image is arranged in a desired range. For example, a Fourier transform image in which four binarized Fourier transform images are arranged is generated. Actually, a Fourier transform image is generated by arranging 20 images of the smallest unit vertically and horizontally, for example. Next, the generated Fourier transform image is converted into electron beam drawing data, and the Fourier transform hologram layer 6 is produced by an electron beam drawing apparatus based on the converted electron beam drawing data. The produced Fourier transform hologram layer 6 has irregularities corresponding to the Fourier transform image. The Fourier transform image may be multi-valued. In this case, the unevenness of the Fourier transform hologram layer 6 has three or more steps. The lattice pitch of the unevenness of the Fourier transform hologram layer 6 is preferably in the range of 1.0 μm to 80.0 μm.

A reflective layer 7 is formed on the uneven surface of the generated Fourier transform hologram layer 6. The reflective layer 7 is, for example, a vapor-deposited film of aluminum, zinc sulfide, titanium oxide, or the like. The reflective layer 7 is preferably made of a material that is reflective to visible light or has a refractive index as large as possible. By forming the reflection layer 7 on the uneven surface of the Fourier transform hologram layer 6, the light incident on the original plate 2 is diffracted by the reflection layer 7, and the Fourier transform hologram reproduction image can be reproduced.

On the other hand, the Lippmann hologram layer 9 is produced by, for example, a two-step method (also referred to as the H1H2 method). 2A and 2B are diagrams illustrating the steps of the two-step method. First, as shown in FIG. 2A, a photosensitive material 11 is prepared, and when the subject 12 arranged apart from the photosensitive material 11 is irradiated with the illumination light L1, the object light L2 reflected by the subject 12 is used as the photosensitive material. In addition to irradiating 11 with reference light L3, the photosensitive material 11 is irradiated with reference light L3 from a direction different from that of the object light L2. As a result, the object light L2 and the reference light L3 interfere with each other on the photosensitive material 11 to form interference fringes, and the H1 hologram 13 is produced. When forming a plurality of interference fringes corresponding to the plurality of subjects 12 on the photosensitive material 11, the process of FIG. 2A may be repeated for each subject 12. At this time, by making the distances between each subject 12 and the photosensitive material 11 equal and making the irradiation range of the object light L2 on the photosensitive material 11 different for each subject 12, different locations on the photosensitive material 11 can be obtained. A plurality of interference fringes can be formed according to each subject 12. The reference light is a laser light having coherence, and for example, a laser light emitted from a DPSS (Diode Pumped Solid State) laser oscillating at 532 nm can be used as the reference light.

Next, as shown in FIG. 2B, the H1 hologram 13 is irradiated with the reproduction illumination light L4 traveling in the direction opposite to the reference light L3 from the side opposite to the incident side of the reference light L3. As a result, the object light L5 is emitted from the H1 hologram 13, and the reproduced image 12a is formed at a position separated by the distance between the H1 hologram 13 and the subject 12. Therefore, the photosensitive material 14 is arranged at this position, and the reference light L6 is irradiated from the side opposite to the H1 hologram 13. As a result, the reference light L6 and the object light L5 interfere with each other on the photosensitive material 14 to form interference fringes, and the H2 hologram 15 is produced. The H2 hologram 15 becomes the Lippmann hologram layer 9.

As shown in FIG. 1, the Fourier transform hologram layer 6 and the Lipman hologram layer 9 produced in the steps of FIGS. 2A and 2B described above are bonded to each other in the layer direction by the transparent adhesive layer 8. It is desirable that the Lippmann hologram layer 9 is arranged closer to the incident surface of light than the Fourier transform hologram layer 6. The reason is that if the reflection layer 7 is formed on the upper surface of the Fourier transform hologram layer 6 and the Lipman hologram layer 9 is arranged below the Fourier transform hologram layer 6, the light does not reach the Lipman hologram layer 9. Because. A part of the reflection layer 7 covering the surface of the Fourier transform hologram layer 6 may be partially removed by the demetalization process. In this case, as an exception, the Lippmann hologram layer 9 can be arranged below the Fourier transform hologram layer 6.

As shown in FIG. 1, when the Lippmann hologram layer 9 is arranged on the incident light side of the Fourier transform hologram layer 6, the cover glass 10 is arranged on the surface of the Lippmann hologram layer 9 to protect the Lippmann hologram layer 9. To do. Further, a base material layer 5 is arranged on the side of the Fourier transform hologram layer 6 opposite to the Lippmann hologram layer 9 side, and a glass layer 3 is arranged on the surface of the base material layer 5 via an adhesive layer 4. There is. The glass layer 3 functions as a protective layer. The base material layer 5 may be arranged on the Lippmann hologram layer 9 side with respect to the Fourier transform hologram layer 6.

The original plate 2 of FIG. 1 is duplicated on the hologram recording member 22 by using the duplicator 21 as shown in FIG. The duplicator 21 of FIG. 3 includes a recording member supply unit 23, a peeling supply head 24, a first separator winding unit 25, a recording member winding unit 26, a protective film ejecting unit 27, and a second separator winding unit. It has a take part 28.

The recording member supply unit 23 supplies the hologram recording member 22 by being guided by the nip roller 29 from the roll body 23a in which the hologram recording member 22 to which the separator 22a is attached is wound in multiple directions. The peeling supply head 24 peels the separator 22a from the hologram recording member 22. The lamirola 35 attaches the recording member 22 to the original plate 2. The first separator winding unit 25 winds the peeled separator 22a. The recording member winding unit 26 winds up the hologram recording member 22 after duplication. The protective film ejection unit 27 supplies a protective film 27a to be attached to the surface of the duplicated hologram recording member 22. When the separator 27b is attached to the protective film 27a, the separator 27b is wound by the second separator winding unit 28.

In the duplicator 21 of FIG. 3, the hologram recording member 22 is moved frame by frame from the recording member supply unit 23, the separator 22a is peeled from the hologram recording member 22, and then the peeling supply head 24 is moved to the left. The hologram recording member 22 for one frame is attached to the upper surface of the original plate 2 by the lamirola 35. FIG. 4 is a cross-sectional view of the hologram recording member 22 arranged on the upper surface of the original plate 2. The hologram recording member 22 has a layer structure in which the base material layer 32 is arranged on the photosensitive material layer 31. In this state, the reference light L7 is incident along a direction inclined with respect to the normal direction of the surface of the hologram recording member 22. The reference light L7 passes through the hologram recording member 22 and is incident on the original plate 2. A part of the reference light L7 is diffracted by the Lipman hologram layer 9 inside the original plate 2, and the diffracted light and the reference light L7 interfere with each other at the photosensitive material layer 31 in the hologram recording member 22 to form interference fringes. It is formed. Further, the other part of the reference light L7 is transmitted through the Lipman hologram layer 9 and diffracted by the reflection layer 7 formed on the uneven surface of the Fourier converted hologram layer 6, and the diffracted light and the reference light L7 are combined. Interferes with the photosensitive material layer 31 in the hologram recording member 22 to form interference fringes.

In this way, the interference fringes (second interference fringes) formed by the Lipman hologram layer 9 and the interference fringes (first interference fringes) formed by the Fourier transform hologram layer 6 are superimposed on the photosensitive material layer 31 of the hologram recording member 22. Is formed.

When the duplication for one frame is completed, the peeling supply head 24 moves to the right in FIG. 3, and the hologram recording member 22 for one frame is peeled from the original plate 2 by the lamir roller 35. On the surface of the hologram recording member 22 for one frame, the protective film 27a unwound from the protective film feeding section 27 is crimped by the nip roller 33 and then wound up by the recording member winding section 26. At this time, the separator 22a for one frame is peeled off from the hologram recording member 22 and wound around the first separator winding unit 25. Next, as the peeling supply head 24 moves to the left, a new hologram recording member 22 for one frame is arranged on the original plate 2. Through the above steps, the hologram element 1 according to the present embodiment is manufactured by the duplicator 21 of FIG.

As described above, the duplicator 21 of FIG. 3 uses the same reference light L7 to record the interference fringes corresponding to the Lipman hologram layer 9 of the original plate 2 and the interference fringes corresponding to the Fourier transform hologram layer 6 as a hologram recording member. Since it is formed by superimposing it on the same photosensitive member of 22, the hologram element 1 according to the present embodiment can be efficiently manufactured, workability is improved, and mass production can be performed in a state where the quality is uniform.

By controlling the incident angle of the reference light L7 with respect to the normal direction of the surface of the hologram recording member 22, the hue of the Fourier transform hologram reproduced image can be adjusted. 5A and 5B are diagrams showing an example of a Fourier transform hologram reproduction image, FIG. 5A shows an example of an incident angle of 30 °, and FIG. 5B shows an example of an incident angle of 40 °. Although it is difficult to understand in FIGS. 5A and 5B because the colors are monochrome and shown, FIG. 5A is visually recognized in green, whereas FIG. 5B is visually recognized in reddish color. Further, in FIG. 5B, it can be seen that color dispersion is caused.

On the other hand, the color of the Lippmann hologram reproduction image (also referred to as a volume reflection type hologram reproduction image) does not change even if the incident angle of the reference light L7 at the time of reproduction is changed.

6A and 6B are diagrams for explaining the reproduction method of the hologram element 1 according to the present embodiment, FIG. 6A shows the reproduction method of the Lippmann hologram reproduction image 41, and FIG. 6B shows the reproduction method of the Fourier transform hologram reproduction image 42. There is. The hologram elements 1 of FIGS. 6A and 6B are formed on both sides of the hologram layer 45 formed by superimposing the interference fringes converted into the Fourier transform hologram reproduction image 42 and the interference fringes converted into the Lipman hologram reproduction image 41. It has a cross-sectional structure in which PET (Polyethylene Terephthalate) layers 46 and 47 are laminated. The PET layers 46 and 47 function as a protective layer for the hologram layer 45. The protective layer may be formed by using a material having visible light transmission other than the PET layers 46 and 47.

When reproducing the Lipman hologram reproduction image 41, as shown in FIG. 6A, in a state where the reproduction illumination light L8 is irradiated along the direction of the incident angle with respect to the normal direction of the surface of the hologram element 1. The observer directs his / her line of sight in the normal direction of the surface of the hologram element 1. As a result, the observer can observe the Lippmann hologram reproduced image 41 near the surface of the hologram element 1.

The reproduction illumination light L8 is LED (Light Emitting Diode) light, laser light, incandescent light, or the like, and basically, the type of the light source 43 does not matter. However, the light needs to include the wavelength of the color component of the Lippmann hologram reproduced image 41. For example, when the Lippmann hologram reproduction image 41 is green, it is necessary to irradiate the reproduction illumination light L8 including the green wavelength band. When the wavelength component of the reproduction illumination light L8 does not include the wavelength of the color component of the Lippmann hologram reproduction image 41, the Lippmann hologram reproduction image 41 cannot be observed from a predetermined direction. The incident angle of the reproduction illumination light L8 may be slightly different from the incident angle of the reference light L7 used at the time of duplication.

Even when the observer directs the line of sight to the hologram element 1 from a direction inclined from the normal direction of the surface of the hologram element 1, the observer observes the Lipman hologram reproduced image 41 of the same color as when observed from the normal direction. be able to.

The direction of the specularly reflected light of the reproduction illumination light L8 and the reproduction direction of the Lippmann hologram reproduction image 41 have different off-axis relationships. Here, off-axis means that the axes are deviated, and that the direction of the specularly reflected light of the reproduction illumination light L8 and the reproduction direction of the volume-reflecting hologram reproduction image 41 are different from each other. On the other hand, the direction of the specularly reflected light of the reproduction illumination light L8 and the reproduction direction of the Fourier transform hologram reproduction image 42 are the same direction.

When reproducing the Fourier transform hologram reproduction image 42, as shown in FIG. 6B, the observer observes the surface of the hologram element 1 with the point light source 44 arranged at a position separated from the surface of the hologram element 1 and lit. Look in the direction of the normal. As a result, the observer can observe the Fourier transform hologram reproduction image 42 in the same plane as the mirror image (reflected light) of the point light source reflected deeper than the surface of the hologram element 1. The point light source 44 is LED light, laser light, incandescent light, or the like, and basically, the specific type of the point light source 44 does not matter. However, the light needs to include the wavelength of the color component of the Fourier transform hologram reproduced image 42.

The interference fringes for reproducing the Fourier transform hologram reproduction image 42 have wavelength selectivity, and even if the reproduction illumination light L9 is, for example, white light, it can be reproduced with monochromatic light. Further, the hue of the Fourier transform hologram reproduced image 42 changes depending on the incident angle of the reference light L7 at the time of duplication. More specifically, as the incident angle of the reference light L7 with respect to the normal direction of the surface of the hologram recording member at the time of duplication increases, the degree of change in the hue of the Fourier transform hologram reproduced image 42 increases. Further, the hue of the Fourier transform hologram reproduction image 42 is also changed by changing the incident angle and the observation direction of the reproduction illumination light in the reproduction stage.

FIG. 7 is an xy chromaticity diagram showing an evaluation result of a Fourier transform hologram reproduction image 42 reproduced by irradiating the hologram element 1 duplicated by the duplicator 21 of FIG. 3 with the reproduction illumination light L9, and FIGS. It is a figure which shows the condition. The closer to the G point in the xy chromaticity diagram of FIG. 7, the closer to green, the closer to B, the closer to blue, and the closer to R, the closer to red.

The xy chromaticity diagram of FIG. 7 shows the evaluation results using a color luminance meter (CS-200 manufactured by Konica Minolta). In the chromaticity distribution diagram of FIG. 7, as shown in FIG. 8A, with respect to the normal direction in a state where the reproduction illumination light L9 is irradiated from an incident angle of 20 ° with respect to the normal direction of the surface of the hologram element 1. The chromaticity of the measurement point P of the Fourier transform hologram reproduction image 42 shown in FIG. 8B, which is observed when the observer turns his / her line of sight in the direction of −20 °, is plotted. More specifically, the xy chromaticity diagram of FIG. 7 plots the chromaticity when the incident angles of the reference light L7 at the time of duplication are 0 °, 10 °, 20 °, 30 °, 40 °, and 50 °. ing.

As can be seen from the xy chromaticity diagram of FIG. 7, the larger the incident angle of the reference light L7 at the time of duplication, the redder the Fourier transform hologram reproduction image 42, and the smaller the incident angle of the reference light L7, the more the Fourier transform hologram. The reproduced image 42 becomes greenish.

By adjusting the incident angle of the reference light L7 at the time of duplication in this way, the hue of the Fourier transform hologram reproduced image 42 can be optimized. Further, depending on the incident angle of the reference light L7, color dispersion occurs in which the hues of the Fourier transform hologram reproduced image 42 are partially different. Due to this color dispersion, at least a part of the Fourier transform hologram reproduced image 42 may be observed in gradation color.

The Fourier transform hologram reproduction image 42 and the Lippmann hologram reproduction image 41 may include arbitrary information such as characters, symbols, patterns, and patterns. As a specific example, the Fourier transform hologram reproduction image 42 and the Lippmann hologram reproduction image 41 may include security information including characters, symbols, patterns, and patterns. This type of security information can be used, for example, for anti-counterfeiting applications.

The hologram element 1 according to this embodiment can be used for various purposes. Typical uses of the hologram element 1 according to the present embodiment include a hologram sheet used as a label body, a transfer foil body, a card embedding body, an information recording medium, and the like, but can also be applied to various other uses. Is.

FIG. 9 is a cross-sectional view of the label body 51 provided with the hologram element 1 according to the present embodiment. The label body 51 of FIG. 9 has a cross-sectional structure in which an adhesive layer 53, a black-colored PET layer 54, an adhesive layer 55, and a separator 56 are laminated in this order below the hologram layer 45 whose surface is covered with the protective film layer 52. .. The hologram layer 45 is formed by superimposing the interference fringes converted into the Fourier transform hologram reproduction image 42 and the interference fringes converted into the Lippmann hologram reproduction image 41. The protective film layer 52 is attached to the hologram layer 45, the hologram layer 45 is cured with UV light, and then the black-colored PET layer 54 is adhered via the adhesive layer 53, and then further via the adhesive layer 55. And the separator 56 is adhered. The separator 56 is peeled off when the label body 51 is attached to various media. If necessary, a functional layer (not shown) having functions such as improvement of adhesion and peelability may be interposed between the layers shown in FIG.

FIG. 10 is a cross-sectional view of the transfer foil body 61 including the hologram element 1 according to the present embodiment. The transfer foil body 61 of FIG. 10 includes a base material layer 69 having a release layer 62 adhered on the hologram layer 45, and a heat seal layer 63 arranged under the hologram layer 45. When the transfer foil body 61 of FIG. 10 is placed on various media and thermocompression bonded from above the base material layer 69, the heat seal layer 63 is thermally melted and the hologram layer 45 is adhered to the medium. Then, the base material layer 69 is peeled off. As a result, the hologram layer 45 can be transferred onto the medium. If necessary, a functional layer (not shown) having functions such as improvement of adhesion and peelability may be interposed between the layers shown in FIG.

FIG. 11 is a cross-sectional view of a hologram sheet used as a card embedding body 65 including the hologram element 1 according to the present embodiment. In the card embedding body 65 of FIG. 11, the heat seal layer 67 is arranged below the hologram layer 45 whose surface is covered with the protective film layer 66, and the separator 68 is arranged below the hologram layer 45. 12A is a plan view of the card 70, and FIG. 12B is a cross-sectional view of the card 70. The card embedding body 65 of FIG. 11 is embedded in the card 70. When embedding in the card 70, the separator 68 is peeled off from the card embedding body 65, the card oversheet 72 is laminated in a state where the heat seal layer 67 is in contact with the card core sheet 71, and thermocompression bonding is performed from above. As a result, the heat seal layer 67 is thermally melted and the hologram layer 45 is adhered to the card core sheet 71. Further, the card core sheet 71 may be provided with a recess, and the card embedding body 65 may be arranged therein. If necessary, a functional layer (not shown) having functions such as improvement of adhesion and peelability may be interposed between the layers shown in FIG.

The hologram sheet used as the card embedding body 65 or the like may include a laser printing layer 73 in addition to the layer structure shown in FIG. 12B. FIG. 12C is a cross-sectional view of the card embedding body 65 provided with the laser printing layer 73. The card embedding body 65 of FIG. 12C has a layer structure in which the laser printing layer 73 is arranged between the heat seal layer 67 of the card embedding body 65 of FIG. 12B and the card core sheet 71. The laser printing layer 73 is a layer in which deterioration such as discoloration, melting, carbonization, foaming, or coloring occurs due to irradiation with laser light. The laser printing layer 73 may be formed of, for example, a polycarbonate resin. The laser printing layer 73 is formed so as to cover the entire surface of the card core sheet 71. The laser beam is emitted from the upper surface side of the card oversheet layer 72. An infrared (IR) laser is usually used for laser printing on the laser printing layer 73. Since the IR laser does not affect the hologram layer 45, it is possible to perform laser printing on a region of the laser printing layer 73 that overlaps the hologram layer 45.

According to the card embedding body 65 of FIG. 12C, arbitrary characters, symbols, patterns, patterns, etc. can be reproduced on the laser printing layer 73 while the Lipman hologram reproduced image 41 and the Fourier transform hologram reproduced image 42 can be reproduced on the hologram layer 45. Can be printed. For example, in the example of FIG. 12A, the Lippmann hologram reproduction image 41 and the Fourier transform hologram reproduction image 42 can be reproduced by the card embedding body 65 on the upper right, and any place other than the card embedding body 65 (for example, indicated by X). The location) can be printed by the laser printing layer 73. The information recorded on the laser printing layer 73 is arbitrary, but at least personal information may be recorded, for example, due to partial alteration by the laser beam.

The card 70 may be one in which personal information or confidential information is recorded, one in which cashable information is recorded, or one used for other purposes. More specifically, the card 70 can be applied to various IC cards, cards having an identification function such as a driver's license, an insurance card, and a membership card, a credit card, a debit card, a security card having a key function, and the like. is there.

Further, the hologram element 1 according to the present embodiment may be built in an information recording medium of various sizes, not limited to the card 70. The information recording medium is a medium or a medium having monetary value that records various information such as personal information such as bills, ID certificates, passports, cash vouchers, tickets, and public documents, and confidential information. The ID card is a national ID card, a license, a membership card, an employee ID card, a student ID card, or the like.

As described above, in the present embodiment, the hologram recording member 22 is placed on the original plate 2 shown in FIG. 1 and the reference light L7 is incident on the hologram recording member 22 along the direction inclined from the normal direction. Interference fringes for reproducing the Fourier transform hologram reproduced image 42 and interference fringes for reproducing the Lipman hologram reproduced image 41 can be superimposed and recorded on the photosensitive material layer 31 in 22. When the point light source 44 is arranged at a position separated from the surface of the hologram element 1 formed in this manner and the point light source 44 is turned on, the Fourier transform hologram reproduction image 42 can be observed. Further, when the reproduction illumination light L8 is incident along the direction inclined with respect to the normal direction of the hologram element 1, the Lipman hologram reproduction image 41 can be observed. By changing the irradiation method of the reproduction illumination lights L8 and L9 in this way, the Lippmann hologram reproduction image 41 and the Fourier transform hologram reproduction image 42 can be reproduced on the same hologram layer 45.

The aspects of the present disclosure are not limited to the individual embodiments described above, but also include various modifications that can be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the contents described above. That is, various additions, changes and partial deletions are possible without departing from the conceptual idea and purpose of the present disclosure derived from the contents defined in the claims and their equivalents.

1 Hologram element, 2 Original plate, 3 Glass layer, 4 Adhesive layer, 5 Base material layer, 6 Surface relief type Fourier conversion hologram layer, 7 Reflective layer, 8 Transparent adhesive layer, 9 Lipman hologram layer, 10 Cover glass, 11 Photosensitive material , 12 subject, 13 H1 hologram, 14 photosensitive material, 15 H2 hologram, 21 duplicator, 22 hologram recording member, 22a separator, 23 recording member supply unit, 23a roll body, 24 peeling supply head, 25 first separator winding unit. , 26 Recording member winding part, 27 Protective film ejection part, 27a Protective film, 27b Separator, 31 Photosensitive material layer, 32 Base material layer, 33 Nip roller, 41 Lipman hologram reproduction image, 42 Fourier conversion hologram reproduction image, 43, 44 light source, 45 hologram layer, 46,47 PET layer, 51 label body, 52 protective film layer, 53 adhesive layer, 54 PET layer, 55 adhesive layer, 56 separator, 61 transfer foil body, 62 release layer, 63 heat seal layer , 65 card embedding, 66 protective film layer, 67 heat seal layer

Claims (15)

The first interference fringes that are converted into a Fourier-transformed hologram reproduction image when light from a point light source that is arranged away from the incident surface is incident, and the direction inclined with respect to the normal direction of the incident surface. A hologram element comprising a hologram layer in which a second interference fringe that is converted into a volumetric reflection type hologram reproduction image is superimposed and recorded when the reproduction illumination light is incident on the incident surface along the incident surface. The hologram element according to claim 1, wherein the incident direction of the regenerated illumination light and the regenerated direction of the volumetric reflection type hologram regenerated image have different off-axis relationships. The Fourier transform hologram reproduction image is observed in the normal direction of the incident surface when the point light source is irradiated from the normal direction of the incident surface.
The volumetric reflection hologram reproduction image is observed in the normal direction of the incident surface when the regenerated illumination light is incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface. The hologram element according to claim 1 or 2. The Fourier transformed hologram reproduction image observed in the normal direction of the incident surface according to the incident angle of the reference light when the second interference fringe is recorded on the hologram layer with respect to the normal direction of the incident surface. The hologram element according to claim 3, wherein the hue of the hologram element changes. The hologram element according to claim 4, wherein the larger the incident angle of the reference light, the greater the hue of the Fourier transform hologram reproduced image observed in the normal direction of the incident surface. When the regenerated illumination light is incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface, the incident surface is observed along the direction of the reflected light of the regenerated illumination light. The hologram element according to any one of claims 1 to 5, wherein the hue of the Fourier transform hologram reproduced image changes. The first interference fringes that are converted into a Fourier-transformed hologram reproduction image when light from a point light source that is arranged away from the incident surface is incident, and the direction that is inclined with respect to the normal direction of the incident surface. A hologram layer is provided in which a second interference fringe that is converted into a volumetric reflection type hologram reproduction image is superimposed and recorded when the reproduction illumination light is incident on the incident surface.
An information recording medium in which at least one of the Fourier transform hologram reproduction image and the volume reflection type hologram reproduction image contains predetermined information. At least, an adhesive layer, a hologram layer, and a protective film layer are sequentially laminated on the separator, and the hologram layer becomes a Fourier-transformed hologram reproduction image when light from a point light source arranged apart from the incident surface is incident. When the first interference fringe to be converted and the regenerated illumination light are incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface, the first interference fringe is converted into a volumetric reflection hologram reproduction image. A label body in which two interference fringes are superimposed and recorded. At least, a hologram layer, a peeling layer, and a base material layer are sequentially laminated on the heat seal layer, and the hologram layer is a Fourier transformed hologram when light from a point light source arranged apart from the incident surface is incident. When the first interference fringes converted into a reproduced image and the regenerated illumination light are incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface, they are converted into a volumetric reflection hologram reproduction image. A transfer foil body recorded by superimposing the second interference fringes to be formed. At least, a heat seal layer, a hologram layer, a protective film layer, and a card oversheet are sequentially laminated on the card core sheet, and the hologram layer is incident with light from a point light source arranged apart from the incident surface. The first interference fringe, which is sometimes converted into a Fourier transformed hologram reproduction image, and the volume reflection type when the reproduction illumination light is incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface. The second interference fringe, which is converted into a hologram reproduced image, is superimposed and recorded.
A card in which at least one of the Fourier transform hologram reproduction image and the volume reflection type hologram reproduction image contains predetermined information. The card according to claim 10, further comprising a laser printing layer that is arranged between the card core sheet and the heat seal layer and is altered by laser light having a predetermined frequency. The laser printing layer is arranged so as to cover the entire surface of the card core sheet.
The card according to claim 11, wherein the hologram layer is arranged on a part of the laser printing layer. The card according to claim 11, wherein at least personal information is recorded on the laser printing layer due to partial alteration by the laser beam. At least, when the heat seal layer, the hologram layer, the protective film layer, and the oversheet are sequentially laminated on the base sheet, and the hologram layer is incident with light from a point light source arranged apart from the incident surface. The first interference fringes that are converted into a Fourier-transformed hologram reproduction image, and the volume-reflecting hologram when the reproduction illumination light is incident on the incident surface along a direction inclined with respect to the normal direction of the incident surface. The second interference fringe converted into a reproduced image is superimposed and recorded.
A hologram sheet in which at least one of the Fourier transform hologram reproduction image and the volume reflection type hologram reproduction image contains predetermined information. A hologram recording member having a photosensitive material layer is placed on an original plate on which a base material layer, a Fourier transform hologram layer, a reflection layer, an adhesive layer, and a volume reflective hologram layer are laminated, and an upper surface of the hologram recording member is placed. A reference light is incident on the upper surface of the hologram recording member along a direction inclined with respect to the normal direction.
A part of the reference light is transmitted through the hologram recording member, incident on the original plate, and diffracted by the volume reflective hologram layer to generate the first diffracted light.
The first diffracted light and the reference light interfere with each other in the photosensitive material layer in the hologram recording member to form a first interference fringe.
The remaining portion of the reference light passes through the volume reflective hologram layer and is diffracted on the surface of the Fourier transform hologram layer to generate a second diffracted light.
A hologram duplication method in which the second diffracted light and the reference light interfere with each other in the photosensitive material layer in the hologram recording member to form a second interference fringe.