JPH04260085A - Hologram cry plate, its production and production of hologram - Google Patents

Abstract

PURPOSE:To offer a hologram dry plate which is effective to form a hologram with little noise on a part of a large substrate or on a curved surface. CONSTITUTION:This hologram dry plate consists of a glass plate 1 having a nonreflecting coat 51 which is optically transparent and other layers successively formed on this plate 1. These layers are (1) adhesive layer 2 having almost an equal refractive index to that of the plate 1, (2) photosensitive layer 3 comprising a gelatine of bichromate, (3) refractive index controlling layer 4 comprising silicone oil, and (4) cover glass having nonreflecting coat 51.

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hologram dry plate, a method for manufacturing the same, and a method for manufacturing a hologram. The present invention can be particularly advantageously used to form a hologram with little noise on a part of a large substrate or on a curved surface.

[Prior Art] A hologram is a recording of the interference wavefront of coherent light such as a laser beam on a recording dry plate as a refractive index distribution, absorbance distribution, unevenness distribution, etc. Also, what is holography technology? , is a technology that regenerates the other light that formed the interference wavefront by irradiating this hologram with light again. Holography is not only widely known as a three-dimensional display, but is also being considered as an optical element that utilizes its wavelength separation function, light deflection function, light convergence function, incident angle selection function, polarization selection function, etc. Incidentally, recently there has been an increasing need to form this hologram on a part of a large substrate or on a curved surface. In other words, this is intended to accommodate the recent diversification of displays. A hologram dry plate is usually manufactured by applying a photosensitive agent from a solution onto a substrate such as a glass substrate to form a photosensitive layer (or also referred to as a photosensitive film). However, this dry plate manufacturing method cannot avoid nonuniformity of the photosensitive agent layer obtained on large substrates or curved surfaces as described above, and therefore cannot obtain satisfactory diffraction efficiency, resolution, etc. In order to solve this problem of non-uniformity of the photosensitive agent layer, instead of applying the photosensitive agent directly to a large substrate, etc., we prepare a separate sheet-like photosensitive agent layer and then apply the photosensitive agent layer to the prepared photosensitive agent layer. A method is usually adopted in which a method is applied to a large substrate, etc., and then exposed to light. This method will be explained with reference to FIG. 11, for example.
As shown in (A), a container 9, such as a pipette, for example.
The photosensitizer (e.g. dichromate gelatin) 94 contained in 3 is transferred to a base film 95 such as a polyester film.
Drip on top. When the film forming process is completed, a photosensitive agent layer 94 is formed on the base film 95, as shown in FIG. 11(B). Next, as shown in FIG. 11C, the previously prepared photosensitive agent layer is applied to a large substrate or curved surface (here, a portion of a large glass plate 98 is shown), with the base film supporting the layer facing outward. At that time, a refractive index adjusting layer 97 such as silicone oil is interposed between the glass plate 98 and the photosensitive agent layer 94 in order to adjust the refractive index. The hologram dry plate 100 obtained in this way has its photosensitive agent layer 94
It is characterized by having a uniform film thickness. but,
It has been found that another problem arises when ordinary hologram exposure is performed using this hologram dry plate. That is, the noise problem is caused by the difference in refractive index between the base film and the photosensitive agent layer, and cannot be adequately addressed even with the interposition of a refractive index adjustment layer. More specifically, in this type of hologram dry plate, an interface occurs between the base film and the photosensitive agent layer, and a portion of the light incident on the dry plate during exposure is reflected, resulting in unnecessary interference fringes. As a result, there is a problem in that noise is reflected in the hologram. At present, no effective solution has been developed to the noise generation caused by the interface between the base film and the photosensitive agent layer. Japanese Unexamined Patent Publication No. 63-29
Publication No. 1082 proposes a method for preventing the generation of noise resulting from the halation phenomenon that occurs on the back side of the support of a hologram dry plate, but this method cannot be used to solve the problems of the present invention. . Japanese Unexamined Patent Publication No. 63-29
The invention described in Japanese Patent No. 1082 includes disposing a member that absorbs a light beam in the optical path after the light beam passes through the record carrier, and mechanically removing the light absorbing member before treatment with the first solvent. By providing this, the purpose is to obtain a suitable backside antireflection effect and prevent the halation phenomenon. According to this invention, as shown in FIGS. 12(A) and 12(B), a light absorbing member 91 is attached to the back surface of a glass plate 102 supporting a hologram optical record carrier 101 via an adhesive layer 92. . The light-absorbing member only needs to have sufficient light-absorbing properties for the wavelength of light used for exposure, but vinyl tape for electrical wiring is used because of its ease of availability. Vinyl tapes come in various colors, but red is particularly suitable. The record carrier after exposure is stored in a special equipment 8.
1 and 82 to remove the antireflection material on the back surface. This allows the light-absorbing material on the back side of the substrate to be placed with an adhesion strength that allows it to be mechanically removed, and by mechanically removing it in the post-exposure process, unnecessary residue can be removed without using a special liquid bath. It has the effect of being able to be removed without leaving any residue.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hologram dry plate that is effective for forming a hologram with less noise on a portion of a large substrate or on a curved surface. Another object of the present invention is to provide a method for manufacturing a hologram dry plate as described above. Yet another object of the present invention is to provide a method for manufacturing a hologram using a hologram dry plate as described above.

[Means for Solving the Problems] The first object of the present invention is to
a transparent support; sequentially laminated on the support;
The following means having a refractive index approximately equal to the refractive index of the support: (1) a photosensitive agent layer, (2) a refractive index adjusting layer, and (
3) When light travels from the side of the photosensitive agent layer toward the atmosphere, there is no reflection of light at the interface between the member and the atmosphere, or even if there is reflection, the reflected light is This can be achieved by a hologram dry plate characterized in that it includes at least a transparent protective member configured to prevent light from entering the photosensitive agent layer. In the practice of this invention, the transparent support can be formed from a variety of materials. Suitable support materials include, for example, glass and various plastic materials. It is preferable that such a support usually has a non-reflective coating on the side in contact with the atmosphere (the side opposite to the photosensitive agent layer). A non-reflective coating is a treatment (coating) that prevents light from being reflected at the interface when light travels from the support side toward the atmosphere (air layer). Also, if the hologram dry plate is exposed to light from only one direction, a reflective film or something similar should be applied instead of the above-mentioned non-reflective coating, or a semi-transparent support should be used instead of a transparent support. It is proposed to use transparent or opaque supports. Here, examples of suitable reflective films include mirrors and metal-deposited films. Additionally, the master hologram can also be used as a support. In the present invention, means such as a photosensitive agent layer supported on a support must have approximately the same refractive index as the support. For example, as a support, the refractive index is 1.
．． When using 52 glass plates, each means has approximately 1
．． Preferably, it has a refractive index of 50 to about 1.55. Further, in the present invention, in order to control the refractive index, it is preferable to interpose a refractive index adjusting layer, for example, made of silicone oil, between the photosensitive agent layer and the uppermost protective member. Note that this refractive index adjusting layer may be omitted depending on the case. A photosensitive layer is applied onto the support, and an adhesive layer is usually interposed to improve bonding between the two. Various commercially available optical adhesives can be advantageously used for forming the adhesive layer. Note that if the photosensitive layer has a predetermined level of tackiness, this adhesive layer can be omitted. The photosensitizer for the photosensitive agent layer can be arbitrarily selected from those commonly used as photosensitizers in this technical field. Suitable photosensitizers include, for example, dichromate gelatin, polymers containing carbazole rings, bleached silver salts, photopolymers,
Examples include thermoplastics. The protective member that constitutes the top layer of the hologram dry plate is used for the purpose of sealing and protecting the photosensitive agent layer.
Like the support described above, it can be constructed from a variety of transparent materials. The protective member preferably consists of a glass plate (cover glass) with an anti-reflection coating on the side in contact with the atmosphere, or otherwise reflects any reflected light in a direction other than the photosensitive agent layer. It can be constructed from a prism. A second object of the present invention is to prepare a transfer sheet consisting of a base film and a photosensitive agent layer formed on the film, and to transfer the transfer sheet to a transparent film when manufacturing a hologram dry plate as described above. At that time, the photosensitive agent layer of the transfer sheet is made to face the support, and the base film of the transfer sheet is peeled off from the obtained integrated structure, and the photosensitive agent layer of the structure is bonded to the support. This can be achieved by a method for producing a hologram dry plate, which is characterized by sequentially laminating a refractive index adjusting layer and a transparent protective member on the top of the film. The transfer sheet in the present invention can be prepared by coating a selected base film with a photosensitizer from a solution. It is recommended that the bonding strength of the photosensitive layer to the base film be adjusted to such an extent that the base film can be easily separated from the integrated structure in the subsequent peeling process. In addition,
Although the material of the base film used here is not particularly limited, suitable materials include various plastic materials, such as those having transparency and flexibility, such as polyester, polycarbonate, polyvinylidene, etc. Can be done. Furthermore, if there is a commercially available product that satisfies the requirements of the transfer sheet of the present invention, it can also be used. For example, commercially available photopolymer films, silver salt films, etc. can be cited as examples. A third object of the present invention is to manufacture a hologram using the above-mentioned hologram dry plate.
The present invention is achieved by a method for producing a hologram, characterized in that the hologram dry plate is exposed by irradiating the hologram dry plate with predetermined interference light from at least the side of its protective member, and the exposed hologram dry plate is developed. The exposure and development steps can be carried out according to techniques commonly used in the manufacture of holograms. For example, exposure of the hologram can be performed using an exposure optical system schematically shown in FIG. That is, two laser beams from the laser LD are incident on the hologram dry plate 10 via a half mirror or the like as shown in the figure. The development of the hologram dry plate after exposure is as follows, for example when the photosensitive agent is made of a polymer containing a carbazole ring: A hologram material mainly composed of a polymer containing a carbazole ring is By exposing the interference pattern to light, a crosslinking reaction of the polymer occurs in the light irradiated area. At this stage there is no refractive index modulation in the material and the image is recorded as a latent image. After immersing this in a first solvent which is a good solvent that hardly elutes the polymer containing carbazole rings but has a swelling effect, the polymer containing carbazole rings By the step of immersing in the second solvent which is a poor solvent, refractive index modulation can be formed and a hologram can be manufactured. This development method of immersing in a good solvent and a poor solvent is a method also used for materials such as bleached silver salt and dichromate gelatin. Examples of the first solvent that is a good solvent include toluene, xylene, mesitylene, ethylbenzene, dichloromethane, dichloroethane, and a mixed solvent of these solvents. Among these, a practically advantageous solvent is xylene or a mixed solvent of xylene and toluene. The second solvent includes n-pentane, n-hexane, n-heptane, n-
Examples include octane, n-propyl alcohol, isopropyl alcohol, and mixed solvents of these solvents.

[Function] The present invention proposes that the film base of the photosensitive agent layer, which causes hologram noise, is not present during exposure, and that a transparent material treated to prevent reflection is used as the protective member. Therefore, in the present invention, noise can be reduced by eliminating the refractive index difference in the thickness direction of the dry plate and preventing the generation of interfaces.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing a preferred example of a hologram dry plate according to the present invention. The hologram dry plate 10 consists of an optically transparent glass plate 1 having an anti-reflection coating 11, as shown. A glass plate 1 used as a support for a dry plate has an adhesive layer 2, a photosensitive agent layer 3, a refractive index adjusting layer 4, and an optically transparent cover glass with an anti-reflection coating 51 formed in sequence above. 5. Note that the glass plate 1 corresponds to a conventional large substrate or a substrate with a curved surface. For example, the hologram dry plate in FIG.
) to (E). First, as shown in FIG. 2(A), the photosensitive agent 3 is dropped onto the base film 6 from the pipette 7 and applied. As shown in FIG. 2(B), a base film 6 (transfer sheet of the present invention) having a photosensitive agent layer 3 is obtained. Next, this transfer sheet is coated with a photosensitive agent layer 3 as shown in FIG. 2(C).
is attached to a glass plate with anti-reflection coating 11 facing inward. In this case, in order to strongly adhere the photosensitive agent layer to the glass plate, the adhesive from the pipette 8 is applied in advance to form the adhesive layer 2. After the photosensitive agent layer has been bonded to the glass plate, the base film used for the transfer sheet is peeled off and removed, as shown in FIG. 3(D). Finally, as shown in FIG. 3(E), after forming the refractive index adjusting layer 4 by dropping the refractive index adjusting liquid from the pipette 9, the cover glass 5 is covered with the anti-reflection coat 51 as the outermost layer. Place it. The hologram dry plate of the present invention, which is manufactured through a series of steps as described above, can be produced by using, for example, dichromate gelatin, which has almost the same refractive index as glass, as a photosensitizer, thereby forming an interface between the glass plate and the cover glass. is no longer present, and light incident from both the top and bottom of this hologram dry plate can pass through the plate without being reflected at all. As a result, in the hologram dry plate of the present invention, unnecessary interference fringes are not formed, and the resulting hologram is clear and free of noise. As already mentioned, the holographic plate of the invention can be modified in various ways within the scope of the invention. For example, when the dry plate 10 of the present invention is designed to be exposed to light from only one direction, a reflective film 12 can be used in place of the non-reflective coating of the glass plate 1 in FIG. (see 4). The reflective film 12 is, for example, a mirror-treated film or a metal vapor deposited film such as aluminum. In addition, the illustrated dry plate 1
In the case of 0, the photosensitive agent layer 3 has tackiness, so as shown in FIG.
Does not have an adhesive layer. Of course, in the hologram dry plate of the present invention, if the photosensitive agent itself is adhesive, as shown in FIG. can also be omitted. Furthermore, the hologram dry plate of the present invention can also have forms as shown in FIGS. 6 to 8. FIG. 6 is an example in which a master hologram is used as the support of the hologram dry plate of the present invention. The hologram dry plate 10 has, as shown in the figure,
It consists of a master hologram 20, a silicone oil layer 4 for adjusting the refractive index, and a photosensitive agent layer 3. In the case of this hologram dry plate, the laser light from the laser LD (arrow indicated by a solid line) is incident, and also apparent light (arrow indicated by a dotted line) is incident thereon. FIG. 7 shows an example in which an optical element with a reflective film is used as the support of the hologram dry plate of the present invention. The hologram dry plate 10 has an aluminum vapor deposited film 3 as shown in the figure.
2, a silicone oil layer 4 for adjusting the refractive index, and a photosensitive agent layer 3. In the case of this hologram dry plate, as well as the dry plate shown in FIG.
Apparent light (arrow indicated by a dotted line) also enters. FIG. 8 shows an example in which a prism is used as a protection member for a hologram dry plate according to the present invention. As shown in the figure, the hologram dry plate 10 includes an optical element 40 with an aluminum vapor-deposited film 42, a silicone oil layer 44 for adjusting the refractive index, a photosensitive layer 43, a silicone oil layer 45 for adjusting the refractive index, and a prism 46. Become. The light emitted from the photosensitive layer 43 of the hologram dry plate does not enter the photosensitive layer again due to the action of the prism 46. Example 1 0.6 g of ammonium dichromate was dissolved in 100 ml of a 4% gelatin aqueous solution to obtain a dichromate gelatin photosensitive solution with a refractive index of about 1.55. This photosensitive solution was added to polyester (
A coating amount of 0 on a base film with a refractive index of 1.67)
．． It was applied dropwise at a rate of 16 ml/cm2. A photoresist film was formed by drying the base film in an atmosphere of 20° C. and 50% RH for 24 hours. Then,
This base film (transfer sheet) with a photosensitive film was bonded to a glass plate (refractive index: 1.52) with an anti-reflection coating. During this bonding, an optical adhesive (refractive index 1.52) is first dropped and applied onto the surface of the glass plate that does not have an anti-reflection coating to form an adhesive layer, and then the previously prepared transfer sheet is applied to the adhesive layer. It was attached to a glass plate with the photosensitive agent layer facing inward. After both were sufficiently bonded, only the base film was peeled off. Next, a refractive index adjustment liquid containing silicone oil as the main liquid and adjusted to have a refractive index of 1.52 was dropped onto the photosensitive layer and developed, and then a cover glass with an anti-reflection coating (refractive index of 1.52) was applied. I sealed it with. In this way, a hologram dry plate of the present invention having anti-reflection coatings on both the upper and lower outermost layers was obtained. The hologram dry plate produced as described above was exposed to light such that the sum of the light amounts of two laser beams was 200 mJ/cm2. The exposed plate was then washed with water until the color was removed and immersed for several minutes in a commercially available photographic hardening fixer (Rapid Fixer available from Kodak). After washing with water, it was immersed in an isopropanol bath for several minutes and dried in hot air. A clear hologram with no noise was obtained. Regarding the hologram dry plate of this example, the noise rate was measured using the exposure optical system shown in FIG. As shown in the figure, the laser beam was made incident on the cover glass of the dry plate 10 at an incident angle of 55°. From the equation in FIG. 10, it was confirmed that the noise rate was 1%. Example 2 (Comparative Example) The method described in Example 1 was repeated, but in this example, for comparison, the base film of the transfer sheet (refractive index 1.67
A refractive index adjusting layer and a cover glass were superimposed on the base film without peeling off the polyester film). A hologram was produced using this hologram dry plate in the same manner as in Example 1, but noise was generated, which was thought to be caused by the presence of the base film. As a result of measurement, it was confirmed that the noise rate of this dry plate was 5%.

[Effects of the Invention] According to the present invention, since there is no base film essential for conventional hologram dry plates, it is possible to not only increase the amount of transmitted light, but also adjust the refractive index and reduce noise. be able to. In addition, since anti-reflection treated glass or a similar transparent material is used as a protective member, it not only effectively holds and protects the photosensitive material surface, but also allows the refraction of the air and the photosensitive material surface in contact with it. It is also effective for adjusting the rate and reducing noise.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a preferred example of a hologram dry plate according to the present invention.

[Fig. 2] Production of a hologram dry plate according to the present invention (Part 1)
FIG.

[Figure 3] Production of hologram dry plate according to the present invention (Part 2)
FIG.

FIG. 4 is a sectional view showing another preferred example of a hologram dry plate according to the present invention.

FIG. 5 is a sectional view showing another preferred example of a hologram dry plate according to the present invention.

FIG. 6 is a cross-sectional view showing an example of how a master hologram is used in the present invention.

FIG. 7 is a cross-sectional view showing an example of use of the optical element with a reflective film in the present invention.

FIG. 8 is a cross-sectional view showing an example of how a prism is used in the present invention.

FIG. 9 is a schematic diagram illustrating a hologram exposure method used in the present invention.

FIG. 10 is a schematic diagram illustrating an exposure optical system used to measure the noise rate of a hologram dry plate.

FIG. 11 is a cross-sectional view showing the manufacturing process of a conventional hologram dry plate in order.

FIG. 12 is a cross-sectional view showing the production of a conventional hologram.

[Explanation of symbols]

1...Glass plate 2...Adhesive layer 3...Photosensitive agent layer 4...Refractive index adjustment layer 5...Cover glass 11...Non-reflective coat 51...Non-reflective coat

Claims (11)

[Claims] 1. A transparent support, and the following means sequentially laminated on the support and having a refractive index substantially equal to the refractive index of the support: (1) a photosensitive agent layer; ) refractive index adjusting layer, and (3) when light travels from the photosensitive agent layer side toward the atmosphere side, there is no reflection of light or there is reflection of light at the interface between the member and the atmosphere. A hologram dry plate characterized in that it comprises at least a transparent protective member configured to prevent reflected light from entering the photosensitive agent layer. 2. The support is a glass plate,
2. The hologram dry plate according to claim 1, further comprising a non-reflective coating on the side in contact with the atmosphere. 3. The hologram dry plate according to claim 1, wherein the support is an optical element and has a reflective film on the side in contact with the atmosphere. 4. The hologram dry plate according to claim 1, wherein the support is a master hologram. 5. The hologram dry plate according to claim 1, further comprising an adhesive layer interposed between the photosensitive agent layer and the support. 6. Claim 1, wherein the photosensitive agent in the photosensitive agent layer itself has adhesiveness, and the photosensitive agent layer is bonded onto the support by utilizing the adhesiveness. The hologram plate described in . 7. The hologram dry plate according to claim 1, wherein the photosensitive agent layer contains dichromate gelatin as a photosensitizing agent. 8. The protective member is a cover glass,
2. The hologram dry plate according to claim 1, further comprising a non-reflective coating on the side in contact with the atmosphere. 9. The hologram dry plate according to claim 1, wherein the protective member is a prism. 10. In producing the hologram dry plate according to claim 1, a transfer sheet consisting of a base film and a photosensitive agent layer formed on the film is prepared, and the transfer sheet is transferred to a transparent support. At that time, the photosensitive agent layer of the transfer sheet is made to face the support, the base film of the transfer sheet is peeled off from the obtained integrated structure, and the photosensitive agent layer of the structure is bonded to the photosensitive agent layer of the structure. A method for manufacturing a hologram dry plate, comprising sequentially laminating a rate adjusting layer and a transparent protective member. 11. In manufacturing a hologram using the hologram dry plate according to claim 1, the hologram dry plate is exposed by irradiating a predetermined interference light from at least the side of its protective member, and then exposed. A method for manufacturing a hologram, comprising: developing a hologram dry plate.