JP4200774B2 - Card-like information recording medium and volume hologram recording method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a card-shaped information recording medium imparted with anti-counterfeiting and entertainment using a volume hologram, and further relates to a volume hologram recording method for this card-shaped information recording medium.
[0002]
[Prior art]
For example, as described in Patent Documents 1 to 5, etc., it has been proposed to use a hologram fixed to a plastic card. Since the hologram has a fine pattern and requires advanced technology for production, forgery or alteration can be countered by applying a hologram sticker as a certificate to a bank card or credit card. Moreover, the hologram can reproduce a pattern, a photograph, etc. as a three-dimensional three-dimensional image, and can give not only a forgery prevention effect but also a high entertainment property and design property to a card.
[0003]
However, conventional holograms that are fixed to a plastic card or the like are all duplicated in advance based on a separately produced original plate, for example, personal information such as a facial photograph or each card It is virtually impossible to include different data. Therefore, there has been no example that has been realized so far, in which volume holograms of individually different information such as face photographs are directly recorded on a card and an ID card or the like imparted with a high level of forgery prevention is immediately issued.
[0004]
On the other hand, for example, in Patent Document 6 and Patent Document 7, a one-step holographic stereogram high-speed printer that produces a hologram by directly recording image information on a photopolymer without requiring an original is developed. These are so-called on-demand printing systems capable of printing different contents one by one at high speed, eliminating the need for masters required for mass production, and processing the captured images etc. to print data to the spatial modulator in the printer. Display and expose the hologram. If such a system is used, it is expected that an image taken on the spot can be immediately issued as a hologram.
[0005]
[Patent Document 1]
JP 2001-315472 A [0006]
[Patent Document 2]
Japanese Patent Laid-Open No. 2002-137582
[Patent Document 3]
JP 2001-322393 A
[Patent Document 4]
Japanese Patent Laid-Open No. 2000-10482
[Patent Document 5]
Japanese Patent No. 2840825 [0010]
[Patent Document 6]
Japanese Patent Laid-Open No. 2001-249606
[Patent Document 7]
JP 2000-89651 A [0012]
[Problems to be solved by the invention]
However, the recording medium used in these systems is a photopolymer coated on a glass or resin substrate, and in order to fix it to a plastic card, a protective cover is provided on the photopolymer, and then a seal is provided. It is necessary to carry out complicated post-processing such as processing and sticking or enclosing the card inside the card so as to be sandwiched between card base materials. Moreover, for example, the method of sticking a card after sealing it as in the former method is not preferable for security because the hologram can be replaced, and the hologram is accidentally damaged even in a normal use environment. There is also a possibility that the reliability of the card is impaired. In addition, in the latter method, a hologram in which an image is recorded is sandwiched between card bases and sealed inside the card, and individual holograms containing personal information may be damaged due to defects occurring in the card molding process. .
[0013]
In addition, plastic cards are generally manufactured in large quantities at once in a dedicated factory equipped with a large device such as a heat press machine. For example, when converting a hologram recording personal information into a card, the card must be It is necessary to manufacture in units of one sheet, and it is virtually impossible to cope with this method from the viewpoint of profitability.
[0014]
The present invention has been proposed in view of such a conventional situation, and it is possible to directly record a volume hologram, and card-like information that can be issued immediately by incorporating different data for each sheet. An object is to provide a recording medium, and further to provide a volume hologram recording method for a card-like information recording medium.
[0015]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the card-shaped information recording medium of the present invention is characterized by having an unexposed photopolymer layer as a volume hologram recording layer.
[0016]
If an unexposed photopolymer layer is formed as a volume hologram recording layer inside a plastic card, it becomes possible to record a hologram directly on a molded card, for example, high-speed printing of different contents one by one In combination with a so-called on-demand print system, it is possible to immediately issue a card containing personal information such as a face photograph or different data for each sheet.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a card information recording medium and a volume hologram recording method to which the present invention is applied will be described with reference to the drawings.
[0018]
As shown in FIGS. 1 and 2, the card-like information recording medium of the present embodiment has a portion of the card 1 as a hologram recording area, and a hologram recording unit 2 capable of individually recording a volume hologram is fitted therein. It is formed. Specifically, the opening 3a is punched and formed in the card base 3 that forms the main body of the card 1 so as to correspond to the hologram recording area, and the hologram recording portion 2 is fitted therein. Here, the hologram recording area is a part of the card 1 here, but is not limited thereto, and may be the entire surface of the card 1, for example.
[0019]
The hologram recording section 2 has an unexposed photopolymer layer 4 capable of recording a volume hologram later as a volume hologram recording layer. However, in this embodiment, transparent barrier layers 5 and 6 are provided on both sides of the photopolymer layer 4 because the handling is difficult only with the unexposed photopolymer layer 4. Highly transparent optical plastic material layers 7 and 8 are bonded to the outside to constitute the hologram recording portion 2.
[0020]
Here, as the unexposed photopolymer material used for the photopolymer layer 4, conventionally known holographic materials can be widely used, and interference fringes caused by interference between the reference light and the object light are recorded as a change in refractive index. Any of these can be used. Specifically, for example, as disclosed in Japanese Patent No. 2849021, (a) a radical polymerizable compound having a 9,9-diarylfluorene skeleton and being liquid at room temperature, (b) a cationic polymerizable compound , A radically polymerizable compound having no 9,9-diarylfluorene skeleton, a compound compatible with the component (a) selected from the group of plasticizers, and (c) a laser beam having a specific wavelength or light with excellent coherence. Photosensitivity for volume hologram recording comprising each component of a photo-radical polymerization initiator system that photosensitizes and polymerizes component (a), and the average refractive index of component (a) is higher than the average refractive index of component (b) A composition, a cationically polymerizable compound that is liquid at room temperature, (b) a radically polymerizable compound, (c) a laser beam having a specific wavelength, or the like, as disclosed in Japanese Patent No. 2873126 A photo-radical polymerization initiator system that polymerizes the component (b) by being sensitive to light having excellent heat-resistance, and (d) low sensitivity to light of the specific wavelength, and sensitive to light of another wavelength. A photosensitive composition for volume hologram recording, comprising each component of a photocationic polymerization initiator system for polymerizing component (a), wherein the average refractive index of component (a) is lower than the average refractive index of component (b) And the like.
[0021]
The holographic material described above is mainly composed of a photopolymerizable photopolymer, and in the initial state, the monomer is uniformly dispersed in the matrix polymer. When this holographic material is irradiated with light having a power of, for example, about 10 to 400 mJ / cm ² , the exposed monomer is polymerized according to the power of the irradiated light, and as a result, the monomer concentration is increased. Varies depending on the location, and refractive index modulation occurs. Thereafter, for example, by irradiating the entire surface with ultraviolet rays having a power of about 1000 mJ / cm ² , the polymerization of the monomer is completed, the degree of refractive index modulation is enhanced, and this refractive index modulation is fixed.
[0022]
In the present embodiment, the holographic material of the photopolymer layer 4 is left unexposed, that is, in the initial state, so that the volume hologram can be recorded later.
[0023]
On the other hand, the transparent barrier layers 5 and 6 and the highly transparent optical plastic material layers 7 and 8 make the thickness of the hologram recording unit 2 coincide with the thickness of the card base 3 and maintain the smoothness of the hologram recording unit 2. It is formed for the purpose of obtaining a hologram that is excellent in recording characteristics and storage stability, has a flatness after hologram recording and fixing, and is bright and easy to see.
[0024]
Therefore, it is preferable to use an optically isotropic material having a refractive index equivalent to that of the photopolymer layer 4 for the highly transparent optical plastic material layers 7 and 8. If the refractive index of the highly transparent optical plastic material layers 7 and 8 is significantly different from the refractive index of the photopolymer layer 4, the light incident obliquely with respect to the perpendicular to the surface of the hologram recording portion 2 is reflected, and the high transparency If the optical plastic material layers 7 and 8 are not optically isotropic materials, the transmitted light is affected by birefringence and the polarization state changes (for example, longitudinally polarized light changes to elliptically polarized light). There arises a disadvantage that the recording characteristics (diffraction efficiency) in the photopolymer layer 4 are lowered.
[0025]
Examples of such highly transparent optical plastic materials used for the highly transparent optical plastic material layers 7 and 8 include cycloolefin materials (for example, trade name ZEONOR manufactured by Nippon Zeon Co., Ltd.), cellulose triacetate (TAC), Examples thereof include polycarbonate, polyolefin resin and the like called refraction. The refractive index of the holographic material constituting the photopolymer layer 4 is about 1.45 to 1.50. For example, the refractive index of the cellulose triacetate (TAC) is 1.48, the retardation is 7 nm, A cycloolefin-based material (for example, trade name ZEONOR manufactured by Nippon Zeon Co., Ltd.) has a refractive index of 1.53 and a retardation of less than 5 nm, and both have good refractive index and optical isotropy.
[0026]
The above-mentioned optically isotropic material tends to be attacked by the solvent contained in the photopolymer layer 4 and tends to cause a chemical change to cause deterioration of characteristics. In particular, in the present embodiment, the photopolymer layer 4 is in a state where the solvent remains, and the deterioration becomes remarkable. Therefore, transparent barrier layers 5 and 6 are provided between the photopolymer layer 4 and the highly transparent optical plastic material layers 7 and 8 to eliminate such inconvenience.
[0027]
Therefore, the transparent resin material used for the transparent barrier layers 5 and 6 is excellent in solvent resistance and needs not to be chemically changed by the solvent contained in the photopolymer layer 4. For example, a polyester resin such as polyethylene terephthalate or the like Polyvinyl alcohol resin or the like can be used.
[0028]
However, for example, when polyethylene terephthalate is used for the transparent barrier layers 5 and 6, since polyethylene terephthalate has birefringence, it is preferable to make it as thin as possible in order to reduce retardation. When the thickness of the transparent barrier layers 5 and 6 made of polyethylene terephthalate is increased, the polarization state of the light transmitted through the polyethylene terephthalate is changed in proportion thereto, and the recording characteristics (diffraction efficiency) of the hologram are lowered. Further, when the refractive index of the transparent barrier layers 5 and 6 is increased, the interface reflection at the transparent barrier layers 5 and 6 is increased, the recording characteristics of the hologram are deteriorated, and the resulting hologram becomes dark.
[0029]
The polyethylene terephthalate has a refractive index of 1.60 to 1.70 in the plane and about 1.49 in the thickness direction. When polyethylene terephthalate is used for the transparent barrier layers 5 and 6, the thickness is 3 μm to 20 μm. It is preferable to set it as the range. If the transparent barrier layers 5 and 6 made of polyethylene terephthalate are too thick beyond the above range, the birefringence becomes a problem. Conversely, if it is less than 3 μm, handling becomes difficult.
[0030]
When such thin transparent barrier layers 5 and 6 are used, it is difficult to apply the photopolymer, and even if it can be applied, it is difficult to support the film and expose the hologram. Therefore, the highly transparent optical plastic material layers 7 and 8 are provided so as to overlap with the transparent barrier layers 5 and 6, and the highly transparent optical plastic material layers 7 and 8 also have a function as a support.
[0031]
The hologram recording unit 2 having the above configuration is manufactured in a separate process from the card substrate 3 and the like, cut into a predetermined size, and inserted into an opening 3 a provided in the card substrate 3. The card-like information recording medium shown in FIG. 1 is produced by hot pressing together with the transparent oversheets 9 and 10 covering the film.
[0032]
The card substrate 3 may be white or transparent, for example. The transparent oversheets 9 and 10 are required to be optically transparent at least in the portion covering the hologram recording portion 2. Polyvinyl chloride (PVC), polycarbonate (PC), polyester, and the like can be used as the material for the card base 3 and the transparent oversheets 9 and 10, and further, JP 2001-71669 A and JP 2001. -80251, JP-A-2001-171274, etc., such as those disclosed as card base materials and oversheet materials, any of the card base materials and oversheet materials used in this type of card can be used. is there.
[0033]
The hologram recording unit 2, the card substrate 3 and the transparent oversheets 9 and 10 are integrated by hot pressing, but the interface between the transparent oversheets 9 and 10 and the card substrate 3, the transparent oversheets 9 and 10 and the hologram recording are integrated. An adhesive or a pressure-sensitive adhesive may be interposed in at least one of the interface of the part 2 and the interfaces of the transparent barrier layers 5 and 6 and the highly transparent optical plastic material layers 7 and 8 in the hologram recording part 2. In that case, the interface between the transparent oversheets 9 and 10 and the hologram recording part 2 and the interface between the transparent barrier layers 5 and 6 and the highly transparent optical plastic material layers 7 and 8 in the hologram recording part 2 are those having high transparency. It is preferable to select and use.
[0034]
In the card-like information recording medium described above, for example, the card base 3 or the transparent oversheets 9 and 10 can be printed to give decoration. Alternatively, it is also possible to provide a magnetic recording part by attaching a magnetic tape to the transparent oversheets 9 and 10 and make various information magnetically recordable therein. Furthermore, it is possible to embed an IC module in a portion other than the hologram recording area to record more information.
[0035]
The card-shaped information recording medium having the above configuration can additionally record different holograms individually by, for example, a one-step holographic stereogram high-speed printer. It is possible to issue cards with data immediately.
[0036]
A high-speed printing system using a one-step holographic stereogram high-speed printer is detailed in, for example, Japanese Patent Application Laid-Open Nos. 2001-249606 and 2000-89651, but here is a system disclosed in Japanese Patent Application Laid-Open No. 2001-249606. A method for recording volume holograms on the card-like information recording medium of the present invention by applying the above will be described.
[0037]
The high-speed printing system described in Japanese Patent Laid-Open No. 2001-249606 collects data from a plurality of cameras or a network such as the Internet once in an image distribution means such as a server computer, and in accordance with an instruction from the server computer, In this system, the collected image data is appropriately allocated to a plurality of hologram printers, and a holographic stereogram is printed.
[0038]
The card-like information recording medium of the present invention is mounted on the printer of the high-speed printing system to record a volume hologram. The configuration of this hologram printer is as shown in FIG. 3, for example. FIG. 3A is a view of the entire optical system of the hologram printer as viewed from above, and FIG. 3B is a view of the main part of the optical system of the hologram printer as viewed from the side.
[0039]
As shown in FIG. 3A, the hologram printer includes a laser light source 21 that emits laser light of a predetermined wavelength, an exposure shutter 22 disposed on the optical axis of the laser light L1 from the laser light source 21, and a half. And a mirror 23.
[0040]
The exposure shutter 22 is closed when the hologram recording medium 20 (the previous card 1 which is the card-like information recording medium of the present invention) is not exposed, and is opened when the hologram recording medium 20 is exposed. The half mirror 23 is for separating the laser light L2 that has passed through the exposure shutter 22 into reference light and object light, and the light L3 reflected by the half mirror 23 becomes reference light. The light L4 transmitted through the mirror 23 becomes object light.
[0041]
On the optical axis of the light L3 reflected by the half mirror 23, as an optical system for reference light, a cylindrical lens 24, a collimator lens 25 for making the reference light parallel, and parallel light by the collimator lens 25. The total reflection mirror 26 that reflects the emitted light is arranged in this order.
[0042]
The light reflected by the half mirror 23 is first made divergent light by the cylindrical lens 24 and then made parallel light by the collimator lens 25. Thereafter, the light is reflected by the total reflection mirror 26 and enters the hologram recording medium 20.
[0043]
On the other hand, on the optical axis of the light L4 transmitted through the half mirror 23, as shown in FIGS. 3A and 3B, the light transmitted from the half mirror 23 is reflected as an optical system for object light. A total reflection mirror 28, a spatial filter 29 combining a convex lens and a pinhole, a collimator lens 30 for collimating object light, a display device 31 for displaying an image to be recorded, and object light for hologram A cylindrical lens 32 for condensing light on the recording medium 20 is arranged in this order.
[0044]
Then, the light L4 that has passed through the half mirror 23 is reflected by the total reflection mirror 28, then is diffused from the point light source by the spatial filter 29, and then is collimated by the collimator lens 30. Incident on the display device 31. Here, the display device 31 is a transmissive image display device made of, for example, a liquid crystal panel, and displays an image based on image data sent from the photographing system. The light transmitted through the display device 31 is modulated in accordance with the image displayed on the display device 31 and then enters the cylindrical lens 32.
[0045]
The light transmitted through the display device 31 is focused in the lateral direction by the cylindrical lens 32, and this focused light is incident on the hologram recording medium 20 as object light. That is, in this hologram printer, the projection light from the display device 31 enters the hologram recording medium 20 as strip-shaped object light.
[0046]
Here, the reference light and the object light are incident on one main surface of the hologram recording medium 20 and the object light is incident on the other main surface of the hologram recording medium 20. That is, in the hologram recording section 2 of the card, both the reference light and the object light are unexposed photo through the transparent oversheets 9, 10, the highly transparent optical plastic material layers 7, 8, and the transparent barrier layers 5, 6. The polymer layer 4 is irradiated.
[0047]
At this time, reference light is incident on one main surface of the hologram recording medium 20 at a predetermined incident angle, and object light is incident on the other main surface of the hologram recording medium 20 with respect to the hologram recording medium 20. So that the optical axis is almost vertical. Thereby, the reference light and the object light interfere on the hologram recording medium 20, and interference fringes generated by the interference are recorded on the hologram recording medium 20 (photopolymer layer 4) as a change in refractive index.
[0048]
The holographic stereogram printer device also includes a recording medium feeding mechanism 33 that can intermittently feed the hologram recording medium 20. The recording medium feed mechanism 33 is recorded each time one image based on the original image data is recorded as one element image on the hologram recording medium 20 set in the recording medium feed mechanism 33 in a predetermined state. Then, the hologram recording medium is intermittently fed by one element hologram. As a result, images based on the original image data are sequentially recorded as element images on the hologram recording medium 20 so as to be continuous in the horizontal direction.
[0049]
In this hologram printer, an image for exposure based on image data is displayed on the display device 31. The hologram recording medium 20 is exposed by opening the exposure shutter 22 for a predetermined time.
[0050]
At this time, out of the laser light L2 emitted from the laser light source 21 and transmitted through the exposure shutter 22, the light L3 reflected by the half mirror 23 enters the hologram recording medium 20 as reference light. Further, the light L4 that has passed through the half mirror 23 becomes projection light on which the image displayed on the display device 31 is projected, and the projection light enters the hologram recording medium 20 as object light. As a result, the exposure image displayed on the display device 31 is recorded as a strip-shaped element image on the hologram recording medium 20.
[0051]
When the recording of one image on the hologram recording medium 20 is completed, the hologram recording medium 20 is then fed by one element hologram by the recording medium feeding mechanism 33.
[0052]
The above operations are repeated by sequentially changing the exposure image displayed on the display device 31 in the order of the parallax image sequence. Thus, the exposure image based on the original image data is sequentially recorded as a strip-shaped element image on the hologram recording medium 20.
[0053]
Here, the hologram printer optimizes the built-in look-up table, image brightness, aspect ratio, etc. based on the shooting information in the management information file, and exposes the holographic stereogram via the exposure shutter 22. Do it. Further, a predetermined number of holographic stereograms are printed out based on the print number information.
[0054]
In the above-described hologram printer, for example, an ID number based on an image data identification ID can be woven into a holographic stereogram. By using the characteristics of the holographic stereogram, it is possible to make the ID number visible only when the holographic stereogram is viewed from a specific angle. Further, when displaying the ID number, it is possible to make only the ID number visible, but it is also possible to synthesize an image of a photographed person and the like with the ID number. Furthermore, it is also possible to perform image processing so that different information can be seen as the viewing position is changed. By incorporating such an ID number, it becomes easy to associate the photographed data with the printed holographic stereogram, which is advantageous in terms of reprinting and customer management.
[0055]
In addition, the hologram printer described above specifies the foreground or background image number to be combined with the original image from the photographing system in accordance with the combined image information in the management information file, and prints the combined holographic stereogram. You can also go out.
[0056]
【The invention's effect】
As is clear from the above description, according to the card-shaped information recording medium and the volume hologram recording method of the present invention, it is possible to directly record a hologram on a molded card, and this is combined with an on-demand print system. Thus, it is possible to immediately issue a card containing personal information such as a face photograph or different data for each sheet.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing an example of a card-like information recording medium to which the present invention is applied.
FIG. 2 is a schematic sectional view showing an example of a card-like information recording medium to which the present invention is applied.
FIG. 3 is a diagram schematically illustrating an example of a hologram printer.
[Explanation of symbols]
1 card, 2 hologram recording part, 3 card substrate, 4 photopolymer layer, 5,6 transparent barrier layer, 7,8 highly transparent optical plastic material layer, 9,10 transparent oversheet

Claims (1)

A card substrate having an opening formed by punching;
An unexposed photopolymer layer; first and second transparent barrier layers disposed on both sides of the photopolymer layer and having durability against a solvent contained in the photopolymer layer; and the first and second transparent barriers It has a laminated structure with optically isotropic first and second highly transparent optical plastic material layers located outside the layer and having a refractive index equivalent to that of the photopolymer layer, and has a thickness equivalent to that of the card substrate. And a hologram recording portion fitted in the opening,
A card-like information recording medium comprising first and second transparent oversheets laminated on both sides of the card base so as to cover the hologram recording part .

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