JP2002071960A - Hologram light diffuser and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a light diffusing body to diffuse light which can be easily erased, rewritten, and duplicated. SOLUTION: The hologram light diffusing body having a diffusing body consisting of a relief pattern on its surface is manufactured by irradiating an azobenzene polymer film 8 with diffused light generated by a glass light diffusing body 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hologram light diffuser capable of diffusing light using a polymer film containing azobenzene, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, in a backlight of a liquid crystal, a headlight of a car, a screen for projection and projection, etc., a diffusing plate such as a ground glass formed with a knurl on the surface of a glass plate is used to diffuse irradiation light. Have been. FIG. 7A is a diagram showing a state where white light is transmitted through the ground glass diffuser plate 13 and diffused, and the diffused light is diffused in a circular shape. FIG. 7B shows another diffusion plate 14 that generates an elliptical diffused light. Alternatively, there is also a method in which a diffusion pattern is recorded on a photosensitive resin on a substrate by interference and developed to form a diffusion plate.

[0003]

By the way, if the light diffusion pattern can be easily changed using the same light diffuser,
In the field of imaging technology, we can provide more diversified images,
Various applications are also possible with other optical application technologies. For example, with backlight light in a display device such as a liquid crystal, if the light diffusion pattern can be changed, the target area to be illuminated relatively brightly in the screen may be located at the center or the entire area depending on the use of the screen. The lighting pattern can be adjusted freely.

However, the diffusion pattern of light by a conventional diffuser such as frosted glass or a diffuser formed by developing a resin is a circular pattern or an elliptical pattern as shown in FIG. However, such a light diffusion pattern is determined and fixed by the shape of the indentation or notch formed on the surface of the glass plate, or the shape of the concavo-convex pattern obtained by developing, and the light diffusion pattern is positively increased. It cannot be controlled. in short,
Conventionally, there has been no idea of changing the diffusion pattern in the same light diffuser and no configuration for realizing it.

[0005] The present invention is an invention developed based on such an idea, and its specific problems are as follows. (1) A light diffuser that causes light diffusion can be easily formed by irradiating light. (2) Perform shaping such as diffusion erasure and rewriting of this light diffuser,
It is easily made possible by light irradiation, heating, voltage application, and the like. (3) It is possible to easily duplicate another light diffuser (replica) having the same diffusion pattern as a certain light diffuser.

[0006]

In order to solve the above-mentioned problems, the present invention provides a hologram in which a polymer film containing azobenzene is irradiated with light having an intensity distribution to form a diffuser made of a relief on the surface. A hologram light diffuser, wherein the light diffuser diffuses light transmitted or reflected by the hologram light diffuser.

[0007] The diffuser is characterized in that it can be erased and rewritten by irradiating light.

[0008] The diffuser is characterized in that it can be erased and rewritten by heating to a high temperature.

[0009] The diffuser is characterized by being shaped by applying a voltage.

[0010] The diffuser is characterized in that the illumination pattern of the light source can be controlled.

In order to solve the above-mentioned problems, the present invention provides a method for producing a hologram light diffuser in which a polymer film containing azobenzene is irradiated with light having an intensity distribution to form a diffuser made of a relief on the surface. A method for producing a hologram light diffuser, wherein the light having the above intensity distribution is diffused light.

The light having the above-mentioned intensity distribution is characterized in that the light source light is diffused light generated by transmission or reflection of a glass light diffuser or a hologram light diffuser which is a replication source.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a light diffuser according to the present invention and a method for manufacturing the same will be described based on examples with reference to the drawings. The present invention relates to an in-line hologram that captures only object light without the need for reference light, characterized in that the hologram light diffuser is formed of an azobenzene polymer film, When a diffused light having an intensity distribution is directly irradiated, a diffuser composed of fine reliefs (irregular patterns) is recorded on the surface.

When the light diffuser on which the diffuser is recorded is irradiated with white light, the transmitted light or the reflected light is reproduced in the same state as the scattered light at the time of recording like a hologram. Therefore, the light diffuser according to the present invention is referred to as a hologram light diffuser in the sense that the state of the original scattered light can be written and recorded. Further, the light diffuser of the present invention can be duplicated, and the diffuser can reproduce the same state as the light diffusion state due to the transmitted light or the reflected light of the original light diffuser so that the hologram light of the copy destination can be reproduced. Recorded on the diffuser.

The mechanism (principle) of this diffuser formation is as follows:
Although it has not been clarified yet, it is considered that the azobenzene polymer is deformed when the azobenzene polymer film is irradiated with light. That is, when a polymer having azobenzene in the side chain is irradiated with laser light having a series wavelength, the azo group changes from a stable trans form to a cis form. Then, it is considered that a relief is formed on the surface in the process of returning from the cis-form to the trans-form again to form a diffuser.

This will be described more specifically. In an experiment of the present invention, a Poly-ora having a structure represented by the following chemical formula 1 was used.
neg tom-l isophoronedisoc
Although yanate (Poly Orange Tom 1) was used, the azo group was changed from a trans form to a cis form by irradiating light having absorption as shown in Chemical Formula 2. The cis form returns to the trans form again. During the repetition, it is considered that the polymer moves according to the radiation pressure generated by (the gradient of) the intensity of the irradiation light.

[0017]

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[0018]

Embedded image

FIG. 1 is a view for explaining an embodiment according to the present invention. FIG. 1 (a) illustrates an azobenzene light diffuser 1 which is an example of a light diffuser according to the present invention, and a method for manufacturing the same. FIG. The method for producing the azobenzene light diffuser 1 is as follows. Laser light generated from the YAG laser device 2 is converted into parallel light beams by the lenses 3 and 4, and the parallel light beams are irradiated on the glass diffusion plate 7 through the opening 6 of the opening 5. I do. And
The diffused light is generated from the glass diffuser 7. This diffuse light,
Irradiate the separately prepared azobenzene polymer film 8.

The diffused light from the glass diffusion plate 7 has a predetermined light intensity distribution, and a diffuser made of relief is formed on the surface of the azobenzene polymer film according to the light intensity distribution. In the present invention, irradiation of diffused light to impart relief to the surface of the azobenzene polymer film to form a diffuser is referred to as "diffuser recording" in the present invention. In this embodiment,
The diffused light to be written uses glass diffused light diffused by glass, but the diffused light may be obtained by other means.

FIG. 1B is a view showing a state in which the azobenzene light diffuser 1 thus formed is irradiated with laser light by the YAG laser device 2 to generate diffused light. Irradiating the light diffuser on which the diffuser is recorded with light to generate diffused light is referred to as "diffuser regeneration" in the present invention. In the case of reproducing the diffuser, white light may be applied instead of laser light.

As described above, the light diffuser recorded with the diffuser is
It can be used as a light diffuser such as a liquid crystal backlight to reproduce a diffuser, generate diffused light, and improve the illuminance of the backlight.

FIG. 2 (a) is a photograph showing the surface condition of a relief (diffuser) formed on the surface of an azobenzene polymer film by the method for producing the azobenzene light diffuser of the present invention. FIG. 2B is a diagram showing a state of the cross section.

The light diffuser according to the present invention is different from the conventional light diffuser shown in FIG. 2 in comparison with a lattice-shaped relief formed on the surface of a glass plate.
As shown in (a) and (b), it is composed of a diffuser composed of a relief having a random direction, and its light scattering effect is extremely excellent.

FIG. 1 (c) is a diagram showing a method for producing a replica of the azobenzene light diffuser 1 produced by recording the above diffuser. In this manufacturing method, FIG.
(A) Similarly, the YAG laser is converted into a parallel light beam by the lenses 3 and 4 and is irradiated to the azobenzene light diffuser 1 as a replication source through the aperture 6 of the aperture 5 to generate diffused light having an intensity distribution. The surface of the newly prepared azobenzene polymer film 9 is irradiated with the diffused light.

Then, the diffused light generated by the azobenzene light diffuser 1 as the copy source has a predetermined light intensity distribution. A duplicate azobenzene light diffuser 10 having a relief having the same shape as the light diffuser 1 is formed. The adbenzene light diffuser according to the present invention can be produced by a very simple process.

By the way, the diffuser of the azobenzene light diffuser 1 can be erased by irradiating it with uniform light having no intensity distribution. Furthermore, rewriting is possible by irradiating the diffuser with light having another intensity distribution.

Furthermore, the diffuser of the azobenzene light diffuser 1 can be erased by heating it to a high temperature, thereby enabling rewriting again. Although the mechanism has not been elucidated, it is considered that the diffuser is softened and flattened and erased by heating.

Further, the pattern of the azobenzene light diffuser 1 can be modulated by applying a voltage. For example, as shown in FIG. 6, a transparent electrode 12 is provided on both sides of the azobenzene light diffuser 1, a voltage is applied to the transparent electrode 12, light is emitted from a light source, and the applied voltage is changed to V1 to V3. As shown in FIGS. 6A to 6C, the pattern can be modulated into a circle, a point, an ellipse, or the like.
This is because the refractive index of the material changes due to the application of a voltage, and the pattern is modulated.

(Experimental Example) FIG. 3 is a photograph showing an experimental example of recording and erasing of a diffuser using an azobenzene polymer film. FIG. 3A shows a diffused state of transmitted light when white light is irradiated to an azobenzene polymer film which is a raw material to which no irradiation is performed.

The raw material azobenzene polymer film is
Diffuser recording was performed in the same manner as in the above example. The recording conditions were as follows: YAG laser wavelength λ = 532 nm, 1
Irradiation was performed at 00 mW / cm ² for 150 minutes. FIG. 3 (b)
The state of diffusion of transmitted light when the azobenzene polymer film on which the diffuser recording has been performed is irradiated with white light is shown. According to the light diffuser on which such a diffuser is recorded, it is recognized that the diffused light is sufficiently diffused.

When the azobenzene polymer film on which the diffuser recording is performed is heated at 150 ° C. for 30 minutes, the diffuser recording is erased. FIG. 3C shows a diffused state of transmitted light when white light is irradiated to the azobenzene polymer film from which such a diffuser record has been erased. According to this, when the diffuser record is erased, the transmitted light is hardly diffused, similarly to the azobenzene polymer film as the raw material shown in FIG.

FIG. 4 is a view showing another experimental example. The diffused state of the transmitted light differs depending on the polarization state of the laser used for recording the diffuser, the aperture pattern of the aperture 5 and the state of the diffuser used. FIG. 3 shows the generation of different transmitted beams.

FIG. 4 (a) is a view showing the diffused state of transmitted light when white light is applied to a light diffuser obtained by performing diffuser recording on an azobenzene polymer film with circularly polarized light. FIG. 4B is a diagram showing a diffused state of transmitted light when white light is applied to a light diffuser obtained by performing diffuser recording with linearly polarized light. In this manner, beam shaping that changes the shape of the transmitted beam can be performed depending on the polarization state of the irradiation laser.

FIG. 4C shows, as an example of beam shaping by the shape of the opening, the transmission when white light is applied to a light diffuser obtained by performing diffuser recording on an azobenzene polymer film through a rectangular opening. FIG. 4 is a diagram illustrating a light diffusion state.

FIG. 5A shows an AFM of a light diffuser obtained by performing a linear linear relief, that is, a linear diffuser recording on an azobenzene polymer film, which was irradiated with white light. FIG. 5B shows the diffused state of the transmitted light in this case.

Although the embodiments of the present invention have been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications may be made within the scope of the technical matters described in the claims. It goes without saying that there are various embodiments.

[0038]

According to the present invention having the above configuration, the following effects can be obtained. (1) A light diffuser that causes light diffusion can be easily formed by irradiating light. (2) Erasing, rewriting, shaping, and the like can be easily performed by applying light, heating, and applying a voltage to the light diffuser. (3) Another light diffuser (copy body) having the same diffusion pattern as a certain light diffuser can be easily copied.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of the present invention, and is a diagram illustrating a light diffuser and a method for manufacturing the same.

FIG. 2 is an AFM image of a specific light diffuser.

FIG. 3 is a view showing an experimental example.

FIG. 4 is a diagram showing another experimental example.

FIG. 5 is a view showing still another experimental example.

FIG. 6 is a diagram showing a state of diffused light when a voltage is applied to a light diffuser while being changed.

FIG. 7 is a diagram illustrating a conventional light diffuser.

[Description of Signs] 1, 10 Azobenzene light diffuser 2 YAG laser device 3, 4 Lens 5, 6 Aperture 7 Glass diffusion plate 8, 9 Azobenzene polymer film

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Claims (7)

[Claims] 1. A hologram light diffuser having a diffuser made of a relief formed on a surface thereof by irradiating a polymer film containing azobenzene with light having an intensity distribution, wherein the diffuser is a hologram light diffuser. A hologram light diffuser, which diffuses light transmitted or reflected by the diffuser. 2. The hologram light diffuser according to claim 1, wherein said diffuser can be erased and rewritten by irradiating light. 3. The hologram light diffuser according to claim 1, wherein said diffuser can be erased and rewritten by heating to a high temperature. 4. The hologram light diffuser according to claim 1, wherein the diffuser is shaped by applying a voltage. 5. The hologram light diffuser according to claim 1, wherein the diffuser is capable of controlling an illumination pattern of a light source. 6. A method for producing a hologram light diffuser in which a polymer film containing azobenzene is irradiated with light having an intensity distribution to form a diffuser made of relief on the surface, wherein the light having the intensity distribution is diffused. A method for producing a hologram light diffuser, which is light. 7. The light of the hologram light diffuser, wherein the light having the intensity distribution is diffuse light generated by transmission or reflection of a light source light from a glass light diffuser or a hologram light diffuser that is a replication source. Production method.