JP2002022962A - Hologram reflection plate and reflection type liquid crystal display device with the same mounted thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to easily and separately manufacture a hologram reflection plate performing display with optional wavelength (color) for realizing display in desired hue without incurring a big increase of the manufacturing cost, in a reflection type liquid crystal display device using the hologram reflection plate. SOLUTION: A volume phase transmission type hologram having wide diffraction wavelength width (white) over a visible wavelength region is utilized and filtering for limiting a desired wavelength region (hue) from diffracted beams of the wide diffraction wavelength width is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a hologram reflector which uses a hologram to control the direction and range (viewing zone) in which display light can be viewed brightly. The technical field in which the hologram reflector is used is a reflection type liquid crystal display device which does not require a special light source such as a backlight or an edge light and uses reflected light due to ambient light (sunlight or indoor lighting) as display light. Typical applications are clocks and mobile phones.

[0002]

2. Description of the Related Art In a reflection type liquid crystal display device of a type having a light reflection layer on the back surface of a liquid crystal panel (the side opposite to a viewer) and using light reflected by ambient light (sunlight or indoor lighting) as display light. Attempts have been made to use holograms as reflective layers instead of existing metal reflective layers.

In the existing metal reflective layer, the intensity of the reflected light becomes highest in the specular reflection direction of the incident light. There is a problem that the directions in which the reflected light from the device becomes brightest overlap. By using the hologram, the control of the viewing zone is realized, and a brighter display in a specific direction can be achieved as compared with the existing metal reflection layer.

As proposals relating to a reflection type liquid crystal display device using a hologram as a reflection plate, the following are known. (1) JP-A-56-51772 (2) JP-T 8-505716 (3) JP-A-9-152586 (4) JP-A-9-222512 (5) International Publication 96 / 37805

There are various types of holograms, and the characteristics of the hologram reflector change accordingly. In the case of a surface relief type hologram, it is difficult to increase the diffraction efficiency, so it is difficult to see a bright display pattern. Will change. This corresponds to (1) above.

In the case of the volume phase reflection type hologram, the wavelength width of reflected and diffracted light is narrow and limited (it becomes a specific color) due to its wavelength selectivity, and a bright display pattern over a visible wavelength range is visually recognized. Is difficult. This is
(2) and (3) apply.

In the case of a volume phase transmission type hologram, since it has a wide diffraction wavelength width over a visible wavelength range (a well-known matter in the technical field, detailed description is omitted).
It is possible to see a bright display pattern due to white reflected light, which corresponds to the above (4) and (5). When a hologram reflector using a volume phase transmission hologram is applied to a display device, white display light is realized. Therefore, by using a (known) color filter in the display device, a full-color image can be obtained. Is suitable for displaying.

Although it is not necessary to provide a full-color display image, it is desirable to give a special hue to display light even in a monochrome display pattern in order to provide an interesting visual effect (eye catch effect). In some cases, it is present depending on the application.

Volume phase reflection type hologram (see (2) and (3) above)
A hologram reflector using a hologram reflector can display light of a specific wavelength (generally green) due to its characteristics, but the diffraction wavelength of the hologram is determined according to the combination of the photosensitive material and the laser beam used for imaging. Therefore, it is not difficult to imagine that it is difficult to separately produce products that reflect light having an arbitrary wavelength (color) from the viewpoint of hologram design and manufacturing equipment, which leads to an increase in manufacturing cost.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a reflection type liquid crystal display device using a hologram reflection plate. In order to realize display with a desired hue, display at an arbitrary wavelength (color) is performed. It is an object of the present invention to make it possible to easily produce hologram reflectors without performing a significant increase in manufacturing cost.

[0011]

According to the present invention, a volume phase transmission hologram having a wide diffraction wavelength width (white) over a visible wavelength range is used.
The above object is achieved by performing filtering for limiting the wavelength to a desired wavelength range (hue).

That is, according to the first aspect of the present invention, in a hologram reflector having a light reflection layer formed on one surface of a volume phase transmission hologram layer, a transparent coloring material is provided between the hologram layer and the light reflection layer. It is characterized by having a configuration in which layers are arranged.

According to a second aspect of the present invention, there is provided a hologram reflection plate having a light reflection layer formed on one surface of a volume phase transmission type hologram layer. And a light-transmitting colored layer.

According to a third aspect of the present invention, there is provided a hologram reflector comprising a light reflection layer formed on one surface of a volume phase transmission hologram layer, wherein the hologram layer contains at least one of a colored pigment and a dye in a photosensitive material. It is characterized in that it has a dispersed configuration.

According to a fourth aspect of the present invention, there is provided a hologram reflector comprising a light reflection layer formed on one surface of a volume phase transmission type hologram layer, wherein the light reflection layer has a reflective filler dispersed therein, and further comprises a coloring pigment. Or formed by applying and forming an ink obtained by dispersing at least one of the dye,
It is characterized by having a configuration also serving as a translucent colored layer.

The light reflection layer formed on one surface (back surface) of the volume phase transmission hologram layer is often composed of a substrate and a reflection layer. As the substrate, any of light scattering and high transparency may be used, but a plastic film excellent in smoothness represented by a polyester film is used.

The reflective layer is made of aluminum,
It is formed by depositing silver, chromium, nickel, or the like, or by applying an ink containing a reflective filler.

As described in the first to third aspects, the light-transmitting colored layer may have various arrangements as appropriate.
In the case of the configuration (light reflecting layer / translucent colored layer / hologram layer), the surface is easily deteriorated particularly in the case of the metal deposition layer, so that it also has a role of protecting the light reflecting surface. In addition, by adjusting the amount of addition (concentration) of a pigment or dye used for determining the hue, not only the hue but also the brightness can be easily adjusted.

[0019]

Embodiments of the present invention will be described below. <Light Reflecting Layer> As the polyester film, Lumirror T60 and Melinex 770 manufactured by Toray, and HS type and Diamond O type manufactured by Teijin are suitable. A light reflecting layer is formed on the base material of the light reflecting layer selected from these by coating or vapor deposition.

<Transparent colored layer> Further, a transparent colored layer is formed thereon. In the case of using a coating method, a photoresist used for an existing color filter (in which a pigment is dispersed) can be used, and for example, V259B manufactured by Nippon Steel Chemical Co., Ltd. is exemplified. In addition, products such as Toyo Ink and Tokyo Ohka are also applicable.

<Volume Phase Transmission Hologram> A volume phase transmission hologram can be photographed and recorded on a photosensitive material for a volume phase hologram using a normal two-beam hologram photographing optical system. Examples of the photosensitive material include dichromated gelatin, silver salt photosensitive material, and photopolymer. As an example, a silver halide photosensitive material 8E56 film for hologram manufactured by AGFA or HRF600 manufactured by DuPont can be used.

In the recording and recording of a hologram, a diffusion plate (ground glass) is used as a subject by using a known recording method.
Images are recorded on the various photosensitive materials described above. In order to obtain white diffracted light, if the photosensitive material is a silver salt, after photographing, CWC2
Developed with a developer, bleached with a PBQ2 bleaching solution, washed and dried, or in the case of HRF600 manufactured by DuPont, subjected to a process according to the photosensitive material, such as performing ultraviolet bleaching after heat development, A volume phase transmission hologram is obtained.

FIG. 1 is an explanatory view (cross-sectional view) schematically showing an example of the configuration of a reflection type liquid crystal display device using the hologram reflection plate of the present invention.

The colored reflection film A has a structure in which a metal vapor-deposited layer serving as the light reflective layer 8 is formed on one surface of the substrate 10 and a light-transmissive colored layer 9 is formed on the vapor-deposited surface. The hologram reflection plate B has a configuration in which a volume phase transmission hologram layer 6 and a polarizing plate 4 are further laminated on the above-mentioned colored reflection film A, and is arranged on the back surface of the liquid crystal panel 2. The colored reflection film A and the polarizing plate 4 are bonded and integrated with the hologram layer 6 via an adhesive or the like.

On the front and back of the liquid crystal panel 2, polarizing plates 3 and 4 are arranged, respectively. When ambient light serving as the illumination light 11 enters the liquid crystal display device, first, only light of one-way polarization component reaches the liquid crystal panel 2 by the first polarizing plate 3, and the liquid crystal panel 2 changes the light according to the display pattern. After the optical rotation, the light reaches the second polarizing plate 4.

The light transmitted through the second polarizing plate 4 is incident on the volume phase transmission type hologram layer 6. The hologram 6 has an angle selectivity. Thus, the incident light passes through the hologram 6 without being diffracted.

The light 7 transmitted through the hologram 6 reaches the translucent colored layer 9 of an arbitrary hue formed on the back surface of the hologram 6, and at the time of transmission, the transmitted light is colored according to the hue (wavelength). The component is limited), the light is regularly reflected by the light reflection layer 8, again transmitted through the translucent colored layer 9, and enters the hologram 6.

The incident light 12 at this time is the first incident light 7
Is incident on the hologram 6 at an incident angle opposite to that of the hologram 6, but coincides with the angle selectivity of the hologram 6, and is then diffracted and emitted as a diffracted light 13 at a specific angle. Diffracted light 1
3 passes through the polarizing film 4, the liquid crystal panel 2, and the polarizing film 3 again, and reaches the observer's eyes 14 as pattern display light. Naturally, the display light is not a monochrome image with a white background, but light having a background color corresponding to the hue of the translucent colored layer 9.

In the above description, the ambient light incident on the display device is not diffracted when first passing through the hologram,
Although the case where the light is diffracted when passing through the hologram again after reflection has been described, the present invention is not limited to such a case, and the angle selectivity of the hologram and the incident angle of the ambient light are not limited. Depending on the relationship, it may be diffracted when first passing through the hologram.

Hereinafter, embodiments of the present invention will be described in detail. <Example 1 = corresponding to claim 1> A polyester film (manufactured by Toray, Lumirror T60; 25 μ thickness) was used as a base material.
One side was subjected to Al deposition (150 ° thickness) to form a light reflection layer. Next, a blue translucent colored layer was applied and formed with a thickness of 2 μm on the Al vapor deposited layer to obtain a colored reflective film.

Next, an argon ion laser (514.5) is used by the above-described two-step photographing and recording method.
nm), a volume phase transmission hologram was exposed and recorded on a silver halide photosensitive material 8E56 film for hologram manufactured by AGFA, and then the hologram was peeled off from the transparent glass.

On the other hand, a pressure-sensitive adhesive (HJ9150W manufactured by Nitto Denko) was laminated on the colored reflection film, and the hologram was adhered to this to obtain a hologram reflection plate.

On the hologram of this hologram reflector,
A polarizing plate for TN liquid crystal (LN type manufactured by PORA TECHNO) was attached to obtain a final hologram reflector.

The polarizing plate side of the hologram reflecting plate is arranged so as to face the liquid crystal panel, and is laminated via an adhesive layer.
The reflective liquid crystal display device having the configuration shown in FIG.

<Example 2 = corresponding to claim 2> As in Example 1, Al was vapor-deposited (150 mm thick) on one surface of the base material.
A light reflection layer was formed. Next, a hologram photographed and recorded in the same manner as in Example 1 was attached to the Al vapor deposited layer to form a hologram reflector (uncolored).

On the other hand, a polarizing plate for TN liquid crystal (L manufactured by PORATECHNO)
N type), a blue light-transmissive colored layer was applied to a thickness of 2 μm to form a colored polarizing plate.

The hologram reflector (uncolored) and the colored polarizer are arranged so that the hologram layer and the translucent colored layer face each other, and are laminated via an adhesive layer. A reflective liquid crystal display device was used.

<Example 3 = corresponding to claim 4> An ink in which an Al filler and a blue pigment were mixed and dispersed was applied to one surface of the same substrate as in Example 1 to form a colored light reflecting layer. .

Next, a hologram photographed and recorded in the same manner as in Example 1 was adhered on the colored light reflecting layer to form a hologram reflecting plate.

On the hologram of this hologram reflector,
A polarizing plate for TN liquid crystal (LN type manufactured by PORA TECHNO) was attached to obtain a final hologram reflector.

The hologram reflector is disposed so that the polarizing plate side faces the liquid crystal panel, and is laminated via an adhesive layer.
The reflective liquid crystal display device having the configuration shown in FIG.

According to the reflection type liquid crystal display device equipped with the hologram reflection plate according to the above embodiment, a display image on a blue background is visually recognized instead of a display image on a white background. In the embodiment, the description was made only for the blue color as the colored light reflecting layer. However, it is needless to say that the colored light reflecting layer in other hues can be appropriately changed.

It is also conceivable that the hologram itself emits colored diffracted light. In this case, at least one of a coloring pigment and a dye is dispersed in a photosensitive material to be a hologram, and otherwise, the hologram is photographed and recorded by the same procedure as in the above embodiment. Just do it. (See Fig. 3)

[0044]

As described above, even with a hologram reflector having the same hologram as a component, the hue of the light emitted from the hologram reflector can be set arbitrarily, and has a hue that matches the taste. The production of the hologram reflection plate becomes easy without causing a significant increase in the production cost.

[0045]

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a configuration of a reflection type liquid crystal display device using a hologram reflection plate of the present invention.

FIG. 2 is an explanatory view showing an example of the configuration of a reflection type liquid crystal display device using the hologram reflection plate of the present invention (claim 1).

FIG. 3 is an explanatory view showing an example of a configuration of a reflection type liquid crystal display device using the hologram reflection plate of the present invention (claim 2).

FIG. 4 is an explanatory view showing an example of the configuration of a reflection type liquid crystal display device using the hologram reflection plate of the present invention (claim 3).

FIG. 5 is an explanatory view showing an example of the configuration of a reflection type liquid crystal display device using the hologram reflection plate of the present invention (claim 4).

[Explanation of symbols]

 A: colored reflective film 2: liquid crystal panel 3: polarizing plate 4: polarizing plate 6: volume phase transmission type hologram layer 8: light reflecting layer 9: translucent colored layer 10: base material

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G02F 1/1335 520 G02F 1/1335 520 F term (Reference) 2H042 DA02 DA11 DA21 DB02 DC02 DC04 DE00 2H049 BA02 BA18 BA43 BA45 BA47 BB03 BB44 BB63 BB66 BC14 BC22 CA05 CA09 CA15 CA30 2H091 FA08X FA08Z FA14Z FA19Z FA41Z FB02 FB08 HA07 LA12 LA16

Claims (8)

[Claims] 1. A hologram reflector having a light reflection layer formed on one surface of a volume phase transmission hologram layer, wherein a light-transmitting colored layer is arranged between the hologram layer and the light reflection layer. The hologram reflector characterized by the above. 2. A hologram reflector having a light reflection layer formed on one surface of a volume phase transmission type hologram layer, wherein a light-transmitting colored layer is formed on the other surface of the hologram layer on which the light reflection layer is not formed. A hologram reflector, wherein the hologram reflector is arranged. 3. A hologram reflector comprising a light reflection layer formed on one surface of a volume phase transmission hologram layer, wherein the hologram layer has a structure in which at least one of a coloring pigment and a dye is dispersed in a photosensitive material. A hologram reflector, comprising: 4. A hologram reflector having a light reflection layer formed on one side of a volume phase transmission hologram layer, wherein the light reflection layer has a reflective filler dispersed therein and further comprises at least one of a colored pigment or a dye. A hologram reflector, which is formed by applying and forming a dispersed ink, and has a configuration also serving as a translucent colored layer. 5. The hologram reflector according to claim 1, wherein the translucent colored layer is formed by applying an ink containing at least one of a colored pigment and a dye. 6. The light-transmitting colored layer is formed by laminating a film formed by dispersing at least one of a colored pigment and a dye inside or coating the surface. Hologram reflector. 7. The hologram reflection plate according to claim 1, wherein a polarizing film is further laminated on a surface facing the liquid crystal panel, on which the light reflection layer is not formed. 8. A hologram reflection plate according to claim 7, which is disposed on the back side of the liquid crystal panel defining the display pattern (the side opposite to the viewer) so that its polarizing film faces the liquid crystal panel. Liquid crystal display device.