JP4492892B2 - Method for manufacturing hologram - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a hologram, and more particularly to a method for manufacturing a hologram having a structure sandwiched between two sheets or films of glass or the like.
[0002]
[Prior art]
A method for producing an optical element such as a microlens by using a hologram is generally performed. Both the relief type and the volume type are used for the hologram. For the volume type, silver salt, dichroate gelatin, various photopolymers, and the like are used as photosensitive materials.
[0003]
In the case of the volume type, most of the photosensitive material used is an organic material, and the material is not weather resistant. It is desirable to seal the photosensitive layer from both sides with a stable material such as glass.
[0004]
At this time, in the case of a fine lens used for a pickup lens or the like, since a small size and a light weight are required, the cover glass is required to be thin.
[0005]
In addition to hologram lenses, there are many holograms having a structure in which two transparent glasses are on both sides. For example, it is used for decorative holograms such as pendants, hologram scanners, and hologram head-up displays.
[0006]
A hologram color filter as described in JP-A-5-12170 also has such a structure.
[0007]
[Problems to be solved by the invention]
FIG. 4 shows a cross-sectional view of a microlens using a hologram. Conventionally, when producing such a hologram, a volume hologram photosensitive layer 2 such as a photopolymer was formed on the transparent glass plate 11 for ease of handling, and a hologram was photographed on the hologram photosensitive layer 2. Thereafter, the transparent glass plate 12 was bonded onto the hologram photosensitive layer 2 using an adhesive or the like.
[0008]
At this time, if the transparent glass plate 12 is thin, it is difficult to maintain its flatness during bonding. If the flatness is poor, problems such as aberration occur and the condensing property of the microlens deteriorates. Moreover, in the actual adhesion of the transparent glass plate 12, it is necessary to consider the film thickness of the adhesive and the shrinkage after the adhesive is cured, which causes the productivity and yield to deteriorate. ing.
[0009]
Further, in the structure of FIG. 4, when the transparent glass plate 11 is thin, it is difficult to form the volume hologram photosensitive layer 2 and handle the hologram at the time of photographing.
[0010]
The present invention has been made in view of the above-described problems of the prior art, and its purpose is that it has good dimensional accuracy and flatness, is simply, has a good yield, is highly productive and is sealed with thin glass. It is to provide a method of manufacturing a hologram.
[0011]
[Means for Solving the Problems]
The method of manufacturing a hologram of the present invention that achieves the above object includes temporarily bonding a first transparent glass plate on a temporary substrate,
Exposing the hologram in the photosensitive layer formed on the surface of the first transparent glass plate on the temporary substrate;
Adhering a second transparent glass plate on the exposed photosensitive layer,
Then, the temporarily bonded temporary substrate is peeled off.
It is the method characterized by this.
[0012]
In this case, temporary adhesion can be performed via a solvent-type acrylic pressure-sensitive adhesive for re-peeling or an adhesive that is peeled off by heating.
[0013]
Further, the exposure of the hologram into the photosensitive layer can be performed by duplication from the hologram as the original plate.
[0014]
In the present invention, the first transparent glass plate is temporarily bonded onto the temporary substrate, the hologram is exposed in the photosensitive layer formed on the surface of the first transparent glass plate on the temporary substrate, and the exposed photosensitive layer is exposed. The second transparent glass plate is bonded to the substrate, and then the temporarily bonded temporary substrate is peeled off. Therefore, the photosensitive layer is easily coated directly on the thin first transparent glass plate by a method such as laminating. And subsequent handling such as exposure becomes easy. Moreover, the flatness of the hologram can be improved by providing the temporary substrate to which the first transparent glass plate is temporarily bonded with flatness. This makes it possible to manufacture a hologram that is simple, has a good yield, is highly productive, and is highly accurate.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the hologram manufacturing method of the present invention will be described with reference to the process diagrams of FIGS.
As shown in FIG. 1 (a), a thin transparent glass plate 12 for a microlens hologram having the structure shown in FIG. 4 is prepared. On the other hand, a glass plate having good flatness, strength, and good handling properties. A temporary substrate 20 is prepared. Then, on the temporary substrate 20, a re-peeling solvent-type acrylic pressure-sensitive adhesive (for example, solvent type acrylic pressure-sensitive adhesives KP-1420, KP-1405, KP-1004, manufactured by Nippon Carbite Industries, Ltd.) KP-1105, Y-1941A), and the thin transparent glass plate 12 is temporarily bonded through a removable adhesive layer 21 made of an adhesive such as wax that is peeled off by heating. Hereinafter, a laminate composed of the transparent glass plate 12 and the temporary substrate 20 temporarily bonded thereto is referred to as a composite substrate 22.
[0016]
Next, as shown in FIG. 1B, a volume hologram photosensitive layer 23 such as a photopolymer is formed on the thin transparent glass plate 12 side surface of the composite substrate 22. Then, the hologram original plate 25 is optically adhered thereon.
[0017]
Then, as shown in FIG. 1C, duplicate illumination light 27 is incident on the hologram original plate 25.
Here, similarly to the volume hologram 2, the hologram master 25, as shown in FIG. 3, includes a diffracted light 28 that converges at one point and a zero-order light 29 that travels straight without being diffracted when the duplicate illumination light 27 enters. Is generated, and they interfere in the volume hologram photosensitive layer 23, and the hologram 2 is duplicated in the layer.
[0018]
The transparent glass plate 11 on the incident side is bonded onto the hologram 2 (23) of the laminate as shown in FIG.
[0019]
In this state, when the temporary substrate 20 is peeled from the composite substrate 22 with the releasable adhesive layer 21 as a boundary, the hologram of the present invention having a configuration as shown in FIG. 2B is obtained.
[0020]
The method for manufacturing a hologram of the present invention has been described based on one embodiment. However, the present invention is not limited to this embodiment, and various modifications can be made. For example, the hologram master 25 may be created by a two-beam interference exposure or a CGH (computer generated hologram) method. Further, the hologram 2 may be produced by two-beam interference exposure without being duplicated. In that case, as will be described with reference to FIG. 3, the parallel light similar to the 0th-order light 29 is used as the reference light, and the condensed light similar to the diffracted light 28 is used as the object light to cause interference in the volume hologram photosensitive layer 23. Just do it.
[0021]
As the adhesive for the releasable adhesive layer 21 for temporarily adhering the transparent glass plate 12 and the temporary substrate 20, an adhesive that is peeled off by heating or the like as described above may be used, but the photosensitive layer 23 and the adhesive layer An adhesive or pressure-sensitive adhesive having an adhesive strength sufficiently weaker than the adhesive strength between the transparent glass plate 11 and the adhesive layer 30 and between the photosensitive layer 23 and the transparent glass plate 12 is sufficient.
[0022]
The volume hologram 2 may be slightly smaller than the transparent glass plates 11 and 12 as shown in FIG. For this purpose, when the hologram 2 is formed on the surface of the first transparent glass plate 12, it may be formed in a small area, or after the film is formed on the entire surface, the periphery is removed before or after exposure. And you may make it a small area. At this time, the two transparent glass plates 11 and 12 may be directly bonded at the portion where the volume hologram 2 does not exist in the adhesive layer 30. Accordingly, even when the volume hologram 2 is not strong, it can be firmly adhered, and at the same time, it can be protected even when the volume hologram 2 is deteriorated by outside air such as moisture or oxygen.
[0023]
As the adhesive used for the adhesive layer 30, any epoxy-based two-liquid curable type, ultraviolet curable type, or the like that can adhere to the volume hologram 2 and the transparent glass plates 11 and 12 can be used.
[0024]
【The invention's effect】
As is clear from the above description, according to the hologram manufacturing method of the present invention, the first transparent glass plate is temporarily bonded onto the temporary substrate, and the photosensitive film formed on the surface of the first transparent glass plate on the temporary substrate is formed. The hologram is exposed in the layer, the second transparent glass plate is bonded onto the exposed photosensitive layer, and then the temporarily bonded temporary substrate is peeled off, so that it is directly on the thin first transparent glass plate. The photosensitive layer can be easily formed by a method such as coating or laminating, and subsequent handling such as exposure becomes easy. Further, the flatness of the hologram can be improved by providing the temporary substrate to which the first transparent glass plate is temporarily bonded with flatness. This makes it possible to manufacture a hologram that is simple, has a good yield, is highly productive, and is highly accurate.
[Brief description of the drawings]
FIG. 1 is a part of a process chart of an embodiment of a hologram manufacturing method of the present invention.
FIG. 2 is the remainder of the process diagram following FIG.
FIG. 3 is a diagram for explaining the operation of CGH which is a duplicate hologram master.
FIG. 4 is a cross-sectional view of a microlens using a hologram according to the present invention.
FIG. 5 is a cross-sectional view showing a modified form of a volume hologram.
[Explanation of symbols]
2 ... Volume hologram 11, 12 ... Transparent glass plate 20 ... Temporary substrate 21 ... Removable adhesive layer 22 ... Composite substrate 23 ... Volume hologram photosensitive layer 25 ... Hologram master 27 ... Duplicate illumination light 28 ... Diffracted light 29 ... 0th order Light 30 ... Adhesive layer

Claims (4)

Temporarily bonding the first transparent glass plate on the temporary substrate;
Into the photosensitive layer formed on the surface of the first transparent glass plate on the temporary substrate, the object light focused on the temporary substrate side and the parallel light reference light are simultaneously incident to expose the microlens hologram,
Then, the second transparent glass plate is bonded on the photosensitive layer after the exposure of the first transparent glass plate surface temporarily bonded on the temporary substrate,
Then, the temporarily bonded temporary substrate is peeled off.
A method for producing a hologram in which both surfaces are sealed with glass.   2. The method for manufacturing a hologram according to claim 1, wherein the temporary adhesion is performed through a re-peeling solvent-type acrylic pressure-sensitive adhesive.   2. The method for manufacturing a hologram according to claim 1, wherein the temporary bonding is performed through an adhesive that peels off by heating.   4. The method for producing a hologram according to claim 1, wherein the exposure of the hologram into the photosensitive layer is performed by duplication from a hologram serving as an original plate.

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