JPH05210081A - LCD projector - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a liquid crystal projector capable of obtaining an image of high quality with high color purity. [Configuration] Liquid crystal display panels 10 and 12 for displaying an image,
16 is provided with liquid crystal coolers 9, 11, and 15, and the refrigerant of this liquid crystal cooler is designed to selectively transmit only light of a specific wavelength to project an image with enhanced color purity. .

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal projector.

[0002]

2. Description of the Related Art A liquid crystal projector irradiates light from a light source onto a transmissive liquid crystal display panel to enlarge and project an image of a television or the like displayed on the liquid crystal display panel onto a screen. In such a conventional liquid crystal projector, light from a light source is dispersed by a dichroic prism into three lights of red (R) component, green (G) component, and blue (B) component, and the light of each component is directly or The corresponding liquid crystal display panel is irradiated through the reflection mirrors, and each color component image is superimposed on the screen and enlarged on a television or the like which is separated into three colors of R, G, and B and displayed on each liquid crystal display panel. There are some that are projected. In order to improve the color purity of a color image on a screen with such a conventional liquid crystal projector, a dichroic mirror is used as a reflecting mirror, or only R, G, and B light components are selectively transmitted. By using a color filter, only the light of each component is selectively reflected or transmitted, and this reflected light or transmitted light is applied to the liquid crystal display panel. In addition, the conventional liquid crystal projector uses three light sources, and the light from each light source is applied to each color filter that selectively transmits only the light of each component of R, G, and B, and this is obtained. The corresponding liquid crystal display panel is irradiated with light of each component, and each of the liquid crystal display panels is provided with R, G, and B.
There is also a system in which each color component image of a television or the like which is separated into colors and displayed is superimposed on a screen and enlarged and projected. Since such a liquid crystal projector uses a color filter, the color purity of the color image on the screen can be naturally improved.

[0003]

However, in such a conventional liquid crystal projector, when the dichroic mirror is used, the cost is high because the dichroic mirror is expensive. On the other hand, when the color filter is used, the color filter generates heat from the light source. There is a problem that the efficiency of light utilization is poor because the function may deteriorate due to fading when the temperature rises due to the heat effect from the light source, and a part of the light from the light source is reflected by the color filter. there were.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to lower the cost as compared with the case where a dichroic mirror is used and to prevent thermal influence such as a color filter. It is an object of the present invention to provide a liquid crystal projector capable of improving the color purity of a color image on a screen without receiving the light and without reducing the utilization efficiency of light.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides:
In order to protect the liquid crystal material, which is weak against heat, from heat in the liquid crystal display panel without using a conventional dichroic mirror or color filter, the liquid refrigerant in the transmissive liquid crystal cooler attached to the liquid crystal display panel has a specific The point is that coloring is performed so that only light in the wavelength region is selectively transmitted, and this is also used as a kind of filter.

[0006]

[First Embodiment] A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a schematic diagram showing a configuration of a main part of a liquid crystal projector. In this liquid crystal projector, the light from the light source 1 such as a xenon lamp is reflected by the parabolic surface of the reflector 2 and enters the dichroic prism 3, where the light of each of the R, G, and B components 4, 5, 6 is received. It is supposed to be distributed in. Of these, the R component light 4 passes through the two reflection mirrors 7 and 8 and the R liquid crystal cooler 9 to illuminate the R liquid crystal display panel 10, and the G component light 5 passes through the G liquid crystal cooler 11 for G light. The liquid crystal display panel 12 is irradiated, and the B component light 6 is irradiated to the B liquid crystal display panel 16 through the two reflection mirrors 13 and 14 and the B liquid crystal cooler 15. As a result, each of the liquid crystal display panels 10, 12 and 16 has R, G, B
Each light image corresponding to each color image of a television or the like separated and displayed in the three colors is a dichroic prism 17
Are combined with each other, passed through the projection lens 18, and superimposed on a screen (not shown) to be enlarged and projected.

Each liquid crystal cooler 9 of this liquid crystal projector,
11 and 15 are structurally the same, and a transparent liquid refrigerant such as an ethylene glycol aqueous solution is placed in a container made of a molded product such as aluminum having a transparent plate such as glass on the light incident surface and the light emitting surface. Although it is a filled structure, the dye added to the liquid refrigerant is different. That is, R
The liquid refrigerant of the liquid crystal cooler 9 for G is added with a dye of a type that selectively transmits only the light of the R component.
A dye of the type that selectively transmits only the G component light is added to the liquid refrigerant 1 and a dye of the type that selectively transmits only the B component light is added to the liquid refrigerant of the B liquid crystal cooler 15. Has been added.

Therefore, in this liquid crystal projector,
In addition to the original liquid crystal cooling function described later, each liquid crystal cooler 9, 11, 15 also has a function as a kind of filter. The performance of the liquid refrigerant and the pigment added thereto does not deteriorate even when heated. Further, even if a dye is added to the liquid refrigerant, it does not reflect the light in the wavelength range to be transmitted. Therefore, in this liquid crystal projector, the cost is lower than the case where the dichroic mirror is used, and further, it is not affected by heat such as a color filter, and the light use efficiency is not deteriorated.
It is possible to improve the color purity of the color image on the screen.

In this liquid crystal projector, the liquid crystal display panels 10, 12, 16 can be cooled. Therefore, the outer shape of the container of the liquid crystal coolers 9, 11, 15 is larger than that of the liquid crystal display panels 10, 12, 16.
The liquid crystal display panels 10, 12, 1 are provided on the outside of the light emitting surface.
6 are overlapped and attached by adhesion or the like. When the liquid refrigerant in the liquid crystal coolers 9, 11, 15 absorbs the heat of the liquid crystal display panels 10, 12, 16 and rises in temperature, the liquid refrigerant is exchanged with the outside air flowing in the projector via a heat pipe, a radiation fin or the like (not shown). Heat exchange is carried out, which cools the liquid crystal display panels 10, 12, 16.

As described above, the reason why the liquid crystal display panel is cooled in the liquid crystal projector is that the temperature inside the liquid crystal display panel is increased due to the temperature rise in the projector due to the irradiation of the infrared ray component contained in the light from the light source or the heat generation of the light source. This is to prevent the liquid crystal substance, which is weak against heat, from being heated and rising in temperature, which enables the normal display operation of the liquid crystal display panel to be continued for a long time.

In the above embodiment, the three liquid crystal display panels 10, 12 and 16 are arranged in a U shape, and the respective light images corresponding to the respective color images are combined by the dichroic rhythm 17. , But is not limited to this. For example, it may be configured as shown in FIG. 2 or FIG.

The same parts as in FIG.
In the liquid crystal projector shown in FIG.
0, 12, 16 are arranged in a straight line, and the respective light images corresponding to the respective color images are passed through dedicated Fresnel lenses 21, 22, 23 and projection lenses 24, 25, 26 and displayed on a screen (not shown). It is designed to be superimposed and enlarged and projected.

The same parts as those in FIG.
In the liquid crystal projector shown in FIG.
The arrangement state of 0, 12, 16 is the same as that shown in FIG. 2, but dedicated light sources 31, 32, 33 and reflectors 3 corresponding to the respective liquid crystal display panels 10, 12, 16 are provided.
It has a structure in which 4, 35 and 36 are provided.

[0014]

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a schematic diagram showing a configuration of a main part of the liquid crystal projector. In this liquid crystal projector, the light from the light source 41 is reflected by the reflector 42, passes through the liquid crystal cooler 43, and illuminates the liquid crystal display panel 44. As a result, the color image of the television or the like displayed on the liquid crystal display panel 44 is enlarged and projected on a screen (not shown) via the Fresnel lens 45 and the projection lens 46.

Also in this liquid crystal projector, the liquid crystal cooler 43
Has a function as a kind of filter, and the spectral characteristics of a plurality of types of colored liquid refrigerant filled in a plurality of layers (not shown) inside are at least R, G, and
The light of each component of B is selectively transmitted, and the light of the remaining component is cut off, for example, in the shaded area in FIG. Therefore, even in this liquid crystal projector, the color image on the screen can be produced at a low cost as compared with the case where the dichroic mirror is used, without being affected by heat such as a color filter, and without lowering the light use efficiency. The color purity of can be improved.

[0016]

As described above, according to the liquid crystal projector of the present invention, the liquid refrigerant in the liquid crystal cooler for cooling the liquid crystal display panel selectively transmits only the light in the specific wavelength range. Since it is colored so that it is used as a kind of filter, it is lower in cost than using a dichroic mirror, and it is not affected by the heat of a color filter, and the light utilization efficiency is high. It is possible to improve the color purity of the color image on the screen without causing deterioration of

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a main part of a liquid crystal projector according to a first embodiment of the present invention.

FIG. 2 is a similar schematic view showing each modification of the first embodiment.

FIG. 3 is a similar schematic view showing each modification of the first embodiment.

FIG. 4 is a schematic diagram showing a configuration of a main part of a liquid crystal projector according to a second embodiment of the present invention.

FIG. 5 is a diagram for explaining spectral characteristics as a kind of filter of the liquid crystal cooler in the second embodiment.

[Explanation of symbols]

 1, 31-33, 41 Light source 9, 11, 15, 43 Liquid crystal cooler 10, 12, 16, 44 Liquid crystal display panel

Claims (1)

[Claims] 1. A liquid crystal in which a transmissive liquid crystal cooler is attached to a transmissive liquid crystal display panel, and heat of the liquid crystal display panel is absorbed by a liquid refrigerant in the liquid crystal cooler to cool the liquid crystal display panel. In the projector, the liquid refrigerant in the liquid crystal cooler is colored so that only light in a specific wavelength region is selectively transmitted.