JPH08194214A - Projection type liquid crystal display device - Google Patents

Abstract

PURPOSE: To obtain a projected image whose color temperature is high, whose color balance is improved, and also, whose light using efficiency is high even in the case of using a halogen lamp whose color temperature is low as a light source, as for a projection type liquid crystal display device using two liquid crystal light valves. CONSTITUTION: The light emitted from the halogen lamp 101 is divided into B light and R and G light by a color separating mirror 103, the B light is intensity-modulated by the liquid crystal light valve A105. And the R and G light are intensity-modulated by two-primary color optical signal through the liquid crystal light valve B106. Besides, the color light undergone the modulation of its intensity by respective liquid crystal light valves are synthesized by a color synthesizing mirror 108, then, enlarged and projected on a screen 110 by a projection lens 109. At this time, the constitutional distribution of the color filter (pixel) of the liquid crystal light valve B106 is made R:G=1:2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system structure and a liquid crystal light valve structure of a projection type liquid crystal display device using two liquid crystal light valves.

[0002]

2. Description of the Related Art A conventional two light valve type projection type liquid crystal display device has a structure represented by Japanese Patent Publication No. 6-17980. Details are shown in FIG.

In FIG. 4, color lights whose intensity is respectively modulated by a liquid crystal light valve 5 having a green filter 5b and a liquid crystal light valve 6 having red and blue filters 6c are combined by a dichroic mirror 4 to form a zoom lens 9.
It is projected on the screen 11 via the, but when viewed in each pixel unit in the projected combined image, the first primary color light is green light, and the second and third primary color lights are respectively It has red light and blue light.

Further, the second and third primary color light pixels have a structure of red light (R): blue light (B) = 1: 1, and each of the primary color lights in the magnified and projected image. Display area, that is,
The area distribution ratio of the optical paths of the three primary color lights passing through the two liquid crystal light valves was red light (R light): green light (G light): blue light (B light) = 1: 3: 1.

[0005]

However, in the above-mentioned projection type liquid crystal display device, the projection image has a hue closer to green light, which is a problem in terms of color reproducibility of the display image. Further, in order to avoid the imbalance of the color distribution, conventionally, a method of inserting an attenuation filter in the optical path of green light to optimize the color balance has been used. It had to be reduced in efficiency and was not a good solution.

Therefore, the projection type liquid crystal display device of the present invention is
Viewed on a pixel-by-pixel basis, it uses two primary color photosynthesis, that is, an optical system with a two liquid crystal light valve configuration, and at the same time, although it uses a halogen lamp that originally has a low color temperature as a light source, it is extremely good. An object of the present invention is to obtain a projection image with high color reproducibility and color temperature and to realize a projection type liquid crystal display device with high light utilization efficiency.

[0007]

PROBLEM TO BE SOLVED BY THE INVENTION A projection light source, and color light separating means for separating white light from the projection light source into first primary color light of RGB three primary colors and other second and third primary color light. , A liquid crystal light valve A for modulating the intensity of the first primary color light
And a second primary color light pixel having a pixel structure of the same pitch as the liquid crystal light valve A and equipped with a color filter corresponding to the second primary color light, and a color filter corresponding to the third primary color light. A liquid crystal light valve B for performing intensity modulation of the second and third primary color lights by positionally disposing the mounted third primary color light pixels on the same substrate, and the liquid crystal light valve A and the liquid crystal light. Projection type liquid crystal composed of color light combining means for optically combining the color light intensity-modulated by the valve B and projection lens means for enlarging and projecting an image formed by the color light combined by the color light combining means on a screen. In the display device, the projection light source is a halogen lamp, the liquid crystal light valve A is used for blue light (B light) of RGB three primary colors, and the liquid crystal light valve B is used for red light (R light). ) And green light (G light), and the compositional distribution of the color filters for the second and third primary color lights of the liquid crystal light valve B is as an area ratio for red light (R): green light ( G) = 1: 2, the area distribution ratio of the optical paths of the three primary color lights passing through the liquid crystal light valve A and the liquid crystal light valve B is red light (R light): green light (G
Light): blue light (B light) = 1: 2: 3.

[0008]

In the projection type liquid crystal display device of the present invention, the projection light source and the white light from the projection light source are the first of the three RGB primary colors.
Color light separating means for separating the primary color light into other second and third primary color lights, a liquid crystal light valve A for performing intensity modulation of the first primary color light, and a pixel having the same pitch as the liquid crystal light valve A. A second primary color light pixel having a structure and a color filter corresponding to the second primary color light and a third primary color light pixel having a color filter corresponding to the third primary color light are formed on the same substrate. A liquid crystal light valve B that is position-selectively disposed in the liquid crystal light valve B for performing intensity modulation of the second and third primary color lights, and the color light intensity-modulated by the liquid crystal light valve A and the liquid crystal light valve B is optically optically. In the projection type liquid crystal display device compatible with full color, it is composed of the color light combining means for combining and the projection lens means for enlarging and projecting the image formed by the color light combined by the color light combining means on the screen. The place in need of three liquid crystal light valves, can be the optical system in two liquid crystal light valves,
The weight and size of the optical system and the control circuit system can be reduced.

Further, the projection light source is a halogen lamp, the liquid crystal light valve A is used for blue light of RGB three primary colors, the liquid crystal light valve B is used for red light and green light, and the liquid crystal is used. Area distribution of the color filter configuration distribution of the light valve B for red light (R): green light (G)
= 1: 2, the area distribution ratio of the optical paths of the three primary color lights passing through the liquid crystal light valve A and the liquid crystal light valve B is red light (R light): green light (G light): blue light (B light) = 1:
With the configuration of 2: 3, even if a halogen lamp having a low color temperature is used as a projection light source, a projected image having excellent light utilization efficiency, high color temperature, and good color balance can be produced.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic configuration diagram showing an overall configuration of an optical system of a projection type liquid crystal display device according to the present invention.

Here, the white light source light emitted from the halogen lamp 101 has its heat rays cut through an infrared cut filter 102, and then is separated by a color separation mirror 103, which is a color light separation means, into first primary colors of RGB three primary colors. The wavelength is selectively separated into blue light (B light) which is light and red light (R light) + green light (G light) which is second and third primary color light.

After that, the blue light (B light) transmitted through the color separation mirror 103 is bent by the mirror 104, reaches the liquid crystal light valve A 105, and is intensity-modulated by the B light image signal. Further, the R light and the G light reflected by the color separation mirror 103 are bent by the mirror 107 to be used for the R light and the G light.
Equipped with a color filter for light and a liquid crystal light valve A
When it reaches the liquid crystal light valve B106 having a pixel structure with the same pixel pitch, it undergoes intensity modulation by the R light image signal and the G light image signal which are the image signals for the second and third primary color lights.

Further, the color lights intensity-modulated by the respective primary color image signals by the liquid crystal light valve A105 and the liquid crystal light valve B106 are combined by a color combining mirror 108 which is a color light combining means, and a projection lens which is a projection lens means as a full color image output. The image is enlarged and projected on the screen 110 from 109.

In the above description, the circuit portion for electrically controlling the colored light by the two liquid crystal light valves is omitted from the drawings and the description for convenience.

Next, the concept of combining the three primary color lights of this embodiment in the optical configuration of FIG. 1 will be described in detail with reference to FIG.

Since all the pixels of the liquid crystal light valve A105 in FIG. 1 function as a light modulator for blue light (B light) (a color filter is not particularly required), the pixel configuration of the emitted image has the color arrangement of FIG. It becomes like A111.

Further, the pixels of the liquid crystal light valve B106 are equipped with color filters for the second and third primary color lights, and function as light modulators for red light (R light) and green light (G light). At the same time, the distribution of the color filters (pixels) is set to red light (R light): green light (G light) = 1: 2, so that the pixel structure of the output image is as shown in the color array B112 in FIG. Become.

The color light (projection light) intensity-modulated by the above-mentioned two liquid crystal light valves is combined by the color combining mirror 108 which is a color light combining means and projected on the screen in the form of the color array C113 of FIG. .

As a result, 1 in row a of the color array C113,
When viewed with 3 pixels of a row 2 and a row 3 pixels, the expression colors are arranged in the order of RB, GB, GB, and this area is R.
= 1, G = 2, B = 3, and red light (R light): green light (G light): blue light (B light) = 1: 2:
The relationship of 3 holds.

Further, even in the three pixels of row b 1, row b 2, and row b 3 of color array C113, the array of expression colors is in the order of GB, RB, GB, The same area ratio relationship as in row a holds.

Further, the area ratio is the same in the c-th row, and this relationship continues for the pixels in the fourth and subsequent columns.

Therefore, when considering the total area distribution of the colored light that captures the nine pixels of 1, 2, and 3 in the abc row in the color array C113, red light (R light) = 3, green light ( G light)
= 6, red light (B light) = 9, and in area ratio, red light (R light): green light (G light): blue light (B light) = 1: 2:
That is, the relationship of 3 holds.

Further, the halogen lamp 101 used as the projection light source generally has an energy ratio with respect to the spectrum of the emitted light such that B light <G light <R light.

The emission spectrum relative energy characteristic 201 of the standard halogen lamp shown in FIG. 3 shows this typical characteristic.

From the characteristic 201 of FIG. 3, the green light (G
Light) center wavelength of blue light (B light) (about 45) when the emission energy of the center wavelength of light (about 570 nm) is 100
The relative value of the emission energy of about 0 nm) and the emission energy of about 200 of the center wavelength (about 700 nm) of red light (R light) can be read.

The characteristics of the halogen lamp 101 (R: G: B = 200: 100: 50 in relative energy value),
The transmission area (R: G: B =) of each color light passing through the liquid crystal light valve A105 and the liquid crystal light valve B106 having different color filter areas (one filter is not provided).
Synergistic effect with 1: 2: 3), a total of 3 in which intensity is modulated and color light is combined through two liquid crystal light valves.
The energy balance of the primary color light has a value close to red light (R light): green light (G light): blue light (B light) = 1: 1: 1. The balance error generated in this case can be completely removed by adjusting the characteristics of the G light and R light color filters and the color light separation mirror.

Therefore, in order to match the amount of blue light energy as in the conventional method, an attenuation filter that requires a large amount of attenuation (when using the lamp of characteristic 201, green light is 1/6 and red light is Without using (decay to 1/4)
Optimized color balance and increased color temperature (higher color rendering)
And it is a translation that is achieved.

[0029]

According to the present invention, the liquid crystal light valve A is used for blue light (B light) of RGB three primary colors, and the liquid crystal light valve B is used for red light (R light) and green light (G light). And the composition distribution of the color filters for the second and third primary color lights of the liquid crystal light valve B in terms of area ratio R: G =
As for 1: 2, the area distribution ratio of the optical paths of the three primary color lights passing through the liquid crystal light valve A and the liquid crystal light valve B is red light (R light): green light (G light): blue light (B light) = 1. :
Due to the configuration of 2: 3, even if a halogen lamp with a low color temperature is used as the projection light source, the light utilization efficiency is extremely excellent, the color temperature is high (high color rendering), and the projected image with good color balance is obtained. A projection type liquid crystal display device that can be created can be realized.

Further, in the liquid crystal light valve B, the distribution ratio of green light with high visibility, that is, the number of green pixels is twice as large as that of red pixels, so that the apparent resolution in the projected image is increased. Can be improved.

Further, in a full-color projection type liquid crystal display device, an optical system can be constituted by two liquid crystal light valves where three liquid crystal light valves are normally required, so that the cost of the display device can be reduced. . Further, it is possible to reduce the weight and size of the optical system and the control circuit system.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a basic configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a configuration of an embodiment of the present invention.

FIG. 3 is a lamp characteristic diagram used in one embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a conventional example.

[Explanation of symbols]

 101 Halogen Lamp 102 Infrared Cut Filter 103 Color Separation Mirror 104 Mirror 105 Liquid Crystal Light Valve A 106 Liquid Crystal Light Valve B 107 Mirror 108 Color Synthesis Mirror 109 Projection Lens 110 Screen 111 Color Arrangement A 112 Color Arrangement B 113 Color Arrangement C 201 Lamp Characteristics

Claims (1)

[Claims] 1. A projection light source, color light separation means for separating white light from the projection light source into a first primary color light of RGB three primary colors and other second and third primary color lights, and the first light source. A liquid crystal light valve A for performing intensity modulation of the primary color light, a pixel structure having the same pitch as the liquid crystal light valve A, and the second
The second primary color light pixel equipped with the color filter corresponding to the primary color light and the third primary color light pixel equipped with the color filter corresponding to the third primary color light are position-selectively arranged on the same substrate. A liquid crystal light valve B for performing intensity modulation of the second and third primary color lights, and color light combining means for optically combining the color lights intensity-modulated by the liquid crystal light valve A and the liquid crystal light valve B, In a projection type liquid crystal display device comprising projection lens means for enlarging and projecting an image formed by the color light combined by the color light combining means onto a screen, the projection light source is a halogen lamp, and the liquid crystal light valve A is the blue light (B
Liquid crystal light valve B is used for red light (R)
Light) and green light (G light), and the component distribution of the color filters for the second and third primary color lights of the liquid crystal light valve B is an area ratio for red light (R): green light. When (G) = 1: 2, the area distribution ratio of the optical paths of the three primary color lights passing through the liquid crystal light valve A and the liquid crystal light valve B is red light (R light): green light (G light): blue light (B). light)
A projection type liquid crystal display device characterized in that it is configured such that = 1: 2: 3.