JPH01107290A - Color hologram - Google Patents

Abstract

PURPOSE:To obtain a color hologram with superior moisture resistance from which a sharp reproduced image having small color fogging is obtained with high diffraction efficiency by including a polymer film where volume phase type holograms of >=2 colors are recorded. CONSTITUTION:The polymer film where volume phase type holograms of >=2 colors are recorded is included. When the color hologram is constituted, there are a one-layer type which uses at least two of light beams of red, green, and blue as recording light for the hologram and performs reproduction with white light, a two-layer type which performs recording in its 1st layer with at least one of red, green, and blue and in its 2nd layer with different light from the 1st layer and performs reproduction with white light, and a three-layer type which performs recording in the respective layers with recording light of red, green, and blue respectively and performs reproduction with white light. Consequently, the bright reproduced image which has high diffraction efficiency and small color fogging is obtained and the moisture resistance of the hologram is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a volume phase type (Lippmann type) color hologram, and more particularly to a color hologram that allows a clear color reproduction image to be obtained with white light.

[Conventional technology]

One of the characteristics of holograms is that information on many objects can be multiplexed onto a single hologram, and by utilizing this principle, color holograms can be realized.

Conventionally, Lippmann color holograms using silver salt photosensitive materials or ceratin dichromate photosensitive materials have been known ("Optics" Vol. 8).
Volume No. 4 August 1979).

However, when silver salt photosensitive materials are used, the light absorption rate is low, resulting in low sensitivity and the need for long exposure times.Special technology is required for the production and development of photosensitive materials, resulting in holograms that are difficult to obtain. The drawback is that it is expensive. In addition, when dichromate gelatin photosensitive materials are used, holograms with low noise and high diffraction effects can be obtained, but on the other hand, they have low sensitivity, the sensitive wavelength range is limited to short wavelengths, and they are extremely sensitive to humidity. There is a practical drawback.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color hologram that has high diffraction efficiency, provides a clear and bright reproduced image with little color cast, and has excellent moisture resistance.

Another object of the present invention is to provide a color hologram that can be manufactured efficiently.

[Means for solving problems]

The above object is achieved by the present invention as follows.

That is, the present invention is a color hologram characterized by including a polymer film recording volume phase holograms of two or more colors, and further comprising a plurality of laminated polymer films recording volume phase holograms of one or more colors. This is a distinctive color hologram.

[For production]

The configuration of the color hologram of the present invention has the following aspects.

1) Red (632,8 nm) as the hologram recording light
, green (514,5 nm), and blue (488 nm) (both use two-color light and are reproduced with white light; 2) at least one color of red, green, and blue in the second layer; 3) A two-layer type in which recording is performed using a second layer of light, and a second layer is recorded using a different light than the first layer, and then reproduced using white light. A three-layer type that records and plays back using white light.

As the polymer film used in the present invention, JP-A No. 53
The vinyl carbazole polymer film described in Japanese Patent No. 15153 is preferable, and for the production of holograms, as described in the same publication, after exposure with a laser beam corresponding to a desired color using a predetermined optical system, the film is exposed to a laser beam corresponding to a desired color. Perform the development process.

Although the reason for this is not clear, a characteristic of vinyl carbazole polymer film holograms is that while exposed at 488 nm, an image that looks as if it had been exposed at 450 nm (blue) is realized during the development stage; During exposure, an image as if exposed at 550 nm (green) can be obtained at the phenomenon stage.

It is also known that red can be produced by triplet sensitization with dyes, and for boat fishing, β-carotene, benzanthracene, azulene, crystal violet, rose bengal, rhodamine B10-damine 6G, etc. Are known.

Furthermore, the deviation of the reproduction wavelength from the recording wavelength of the vinyl carbazole polymer film can be shifted to either the long wavelength side or the short wavelength side by changing the development conditions.

In order to laminate polymer films in the present invention, a recorded film may be used as a substrate to laminate the second and subsequent layers, or a recorded film and another film may be laminated. In addition, in the case of overlapping the films, a layer made of an adhesive or an adhesive may be interposed between the films to make them more closely fixed.

Furthermore, a glass film or the like can be laminated on the hologram observation surface, which is transparent to the extent that it does not interfere with the color characteristics during color display and does not have a particular absorption band in the wavelength range of the color characteristics.

It is common practice to use an adhesive or a pressure-sensitive adhesive layer on the open surface of the glass film or the like and the recorded film, and there is no hindrance to its use as long as it does not adversely affect the hologram image.

Furthermore, it is possible to provide a transferable color hologram sheet by providing an adhesive/pressure-sensitive adhesive layer on the recorded film, glass, transparent film surface, etc.

〔Example〕

The present invention will be specifically described below with reference to Examples.

Example 1 2.0 g of Yopolyvinyl Rubazole, 0. ．．
2 g, 0.2 g of 2.6-di-t-butylphenol was dissolved in 20 g of monochlorobenzene, coated with a spinner on a 1.0 mm thick glass plate whose surface had been polished in a dark place, and air-dried in a dark place. A photosensitive material for holograms with a diameter of 4 μm was obtained.

This sensitive material was heated using an argon laser at 458 nm and 514 nm.
Exposure was performed using a 5 nm bright line. This photosensitive material was then immersed in xylene at 25°C for 2 minutes.

After removing and swelling the photosensitive element by n
- A volume phase hologram plate was obtained by washing and shrinking with a shrinking liquid consisting of hexane. This hologram is 51
Approximately 2800 lines/mm at 4.5 nm, approximately 29 lines/mm at 479 nm
It had a spatial frequency of 00 lines/mm, and its diffraction efficiency was 85% each.

When the resulting hologram was irradiated with a halogen lamp to reproduce the image, a clear color image was obtained.

Example 2 A hologram photosensitive material was obtained by following the same recipe as in Example 1 except that 0.2 g of Rhodamine 6G was added to the photosensitive material solution. This sensitive material was exposed to 458n of argon laser.
m, 514. jnm, helium-neon laser 63
Exposure was performed using a 3 nm bright line.

This hologram has a wavelength of 514.5nm and approximately 2700 lines/mm.
, about 2900 lines/mm at 479 nm.

It had a spatial frequency of about 2500 lines/mm at 633 nm, and its diffraction efficiency was 80 and 85.78%, respectively.

When the resulting hologram was irradiated with a halogen lamp to reproduce the image, a clear color image was obtained.

Example 3 A hologram film was obtained by exposing to a bright line of 633 nm in the same manner as in Example 2 using a sensitive material in which polyvinylcarbazole (2.0 g) and rose bengal (0.2 g) were dissolved in 20 g of monochlorobenzene. This film was brought into close contact with the film of Example 1 to obtain a volume phase hologram plate.

This hologram has a wavelength of 514.5nm and approximately 2800 lines/m
m, approximately 2900 lines/mm at 479 nm
.

It had a spatial frequency of 2600 lines/mm at 633 nm, and its diffraction efficiency was 85%, 85%, and 80%, respectively.

When the resulting hologram was irradiated with a halogen lamp to reproduce the image, a clear color image was obtained.

Example 4 Using the hologram sensitive material of Example 1, 514.5 nm and 4
Two green and blue hologram plates were obtained using a 79 nm emission line, respectively.

The hologram film of Example 3 exposed to the 633 nm bright line was brought into close contact with these two films to obtain a volume phase hologram.

This hologram has a wavelength of 514.5,479nm and approximately 280 nm.
It has a spatial frequency of 0 lines/mm and 2700 lines/mm at 633 nm, and its diffraction efficiency is 80 and 82.80%, respectively.
Met.

When the resulting hologram was irradiated with a halogen lamp to reproduce the image, a clear color image with little color cast was obtained.

Example 5 The same method as in Example 4 was used except that, unlike Example 1, the hologram sensitive materials for 514.5 nm and 479 nm were developed at 30° C. and 220° C., respectively.

This hologram is 550nm, 450nm is about 2800
It had a spatial frequency of 2700 lines/mm at 633 nm and 2700 lines/mm, and its diffraction efficiency was 85.83.80%, respectively.

When the resulting hologram was irradiated with a halogen lamp to reproduce the image, a clear color image with little color cast was obtained.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a bright reproduced image that has high diffraction efficiency and is clear and has little color cast.

Furthermore, since a vinyl carbazole polymer is used as the polymer film, the hologram has extremely excellent moisture resistance.

Claims (4)

[Claims] (1) A color hologram characterized by having a polymer film recording volume phase holograms of two or more colors. (2) The color hologram according to claim 1, wherein the polymer film is made of a vinyl carbazole polymer. (3) A color hologram characterized by laminating a plurality of polymer films recording volume phase holograms of one or more colors. (4) The color hologram according to claim 3, wherein the polymer film is made of a vinyl carbazole polymer.