JPH10271421A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the image display device using a light bulb with ease of setup to provide uniform luminance/chromaticity at all times. SOLUTION: In the image display device configured with a light source 3, a color separation means 8 that separates a white light from the light source 3 into red, blue and green color components in dichroic mirrors 5, 7 whose characteristics are set between optical characteristics for P, S polarized lights and with a liquid crystal display panel 16 that modulates each separated color light, polarization axis selection means 10, 11, 12 that continuously convert directions of polarization are provided between the color separation means 8 and the liquid crystal display panel 16. Since the color light in a range from a P polarized light component to an S polarization component is used by changing a characteristic of the polarization axis selection means, the chromaticity and the luminance of the image display device are easily adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device using a light valve, and more particularly to an image display device used as a multivision by combining at least two liquid crystal projectors or liquid crystal monitors.

[0002]

2. Description of the Related Art In recent years, as a large-screen image display device, a multi-vision system in which a plurality of rear-integrated CRT projectors can be stacked and a single screen is displayed on the plurality of CRT projectors has been widely used. It is often used in public facilities such as stations. In these general systems, a video signal or a computer signal is divided by an image enlarging device into images corresponding to the number of projectors in the system configuration, and each image is received. This is a system that can display video signals and combine them to realize one large screen.

[0003]

However, in a conventional CRT type projector, it is necessary to drive each of the CRTs for red, blue and green to display colors. It was necessary to adjust the convergence of blue and green.

In order to solve the above-mentioned problems, multi-vision systems using liquid crystal have been studied by various companies. The life of a light source lamp used in a projection engine for projecting the liquid crystal image is longer than that of a CRT. And the brightness and chromaticity change according to the usage time.

As means for solving this problem, Japanese Patent Laid-Open Publication No. Hei 6-148624 discloses that a lighting time of a lamp is stored in a memory and a color temperature is adjusted according to the lighting time. The life spans are different,
It is not possible to manage the chromaticity only by managing the lighting time. Furthermore, since a plurality of units are stacked and used, even a small variation in luminance and chromaticity cannot achieve a uniform large screen, and the adjustment must take a very long time. .

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a light source and a dichroic mirror in which white light from the light source is set between optical characteristics when P and S polarized lights are used. In an image display device including a color separation unit that separates red, blue, and green color components, and a light valve that can modulate each of the separated color lights, the polarized light is interposed between the color separation unit and the light valve. An image display device provided with a polarization axis selecting means for continuously changing the direction, or a projection type image display in which the color-separated color light is modulated by a light valve and then projected by a color combining means and a projection lens Device.

Further, between the light source and the light valve,
An image display device comprising a polarization axis selecting means capable of changing the polarization direction and automatically changing the polarization direction by the polarization axis selecting means when an input signal is switched.

Further, in the image display apparatus constituted by combining a plurality of the light valves, means for detecting the chromaticity of the projection light emitted from the projection lens, and the light is incident on each light valve based on the chromaticity information of the detected light. This is an image display device that is a λ / 2 plate that is optimally rotatable for the wavelength of color light and that can continuously change the polarization direction.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a light source and a dichroic mirror which sets white light from a light source between optical characteristics when P and S polarized lights are used. In an image display device comprising a color separation unit for separating light into light and a light valve capable of modulating each of the separated color lights, the polarization direction can be continuously changed between the color separation unit and the light valve. The polarization axis selection means is continuously changed, so that color light in the range from the P-polarized light component to the S-polarized light component can be used. Can be easily adjusted. Therefore, even if the spectral characteristics of the light source and the spectral transmittance characteristics of the dichroic mirror vary, the polarization axis selecting means can adjust the chromaticity to an arbitrary value.

Further, according to the present invention, a light source and white light from the light source are separated into red, blue and green color components by a dichroic mirror set between optical characteristics when each of P and S polarized lights is used. In an image display device including a color separation unit and a light valve that can modulate each of the separated color lights, a polarization axis selection unit that can continuously change a polarization direction between the color separation unit and the light valve. Means for modulating the color-separated color light with a light valve, and then projecting it with a color combining means and a projection lens, whereby the chromaticity and luminance of the projected light can be continuously adjusted. It has the action of:

Further, according to the present invention, there is provided a polarization axis selecting means for changing the polarization direction between the light source and the light valve, and when the input signal is switched, the polarization direction is automatically changed by the polarization axis selecting means. It has an effect that it can be converted into a desired polarization direction when each input signal is switched in accordance with an input signal that emphasizes chromaticity or an input signal that emphasizes luminance.

According to another aspect of the present invention, there is provided an image display apparatus configured by combining a plurality of units, wherein a means for detecting chromaticity of projection light emitted from the projection lens is provided based on chromaticity information of the detected light. A λ / 2 plate that is optimally rotatable for the wavelength of the color light incident on each light valve and is capable of continuously changing the polarization direction. Light sources between devices generated when a plurality of light valves are combined Even if there is a variation due to the spectral characteristics of the dichroic mirror or the spectral transmittance characteristics of the dichroic mirror, the polarization axis selecting means can adjust the chromaticity to an arbitrary value based on the detected result.

Hereinafter, embodiments of the liquid crystal display device of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram of an image display device of the present invention.

Light emitted from a lamp 1 such as a halogen lamp or a metal halide lamp is converted by a parabolic mirror 2 into parallel light. The parallel light from the light source 3 is blocked by the ultraviolet / infrared cut filter 4 from transmitting ultraviolet and infrared rays to the front surface, and then enters the color separation means 8. The color separation means 8 separates white light from a light source into blue, green, and red color lights by the blue reflection dichroic mirror 5 and the red reflection dichroic mirror 7. The blue, green, and red color lights separated by the color separation means 8 are incident on the λ / 2 plates 10, 11, and 12, respectively. The λ / 2 plate is generally used for inversion of circularly polarized light and elliptically polarized light, azimuth conversion of linearly polarized light, and the like. λ / 2 plate 10, 1
Reference numerals 1 and 12 are arranged to control the spectral distribution of linearly polarized color light used by the liquid crystal panel 16.

Light emitted from the λ / 2 plates 10, 11, and 12 is incident on a flat microlens 41 that matches the pixel pitch of a liquid crystal panel 16 having a polarizing plate 13 on the incident side and a polarizing plate 15 on the emitting side. The light is refracted at a desired angle in order to transmit color light suitable for the color of the pixel of the liquid crystal panel 16. Each pixel of the liquid crystal panel 16 displays an image to be displayed by a drive circuit (not shown), so that an observer on the light emission side can recognize a full-color image.

FIG. 2 shows the spectral transmittance characteristics of the dichroic mirror 5 used in the present invention. Here, the solid line is the P-polarized light component, the one-dot chain line is the S-polarized light component, and the dotted line is the characteristic of the average value component of the P-polarized light and the S-polarized light of the dichroic mirror 5 used in the present invention. By rotating the λ / 2 plate 10, the liquid crystal panel 16 can use the color light in the range from the P-polarized component to the S-polarized component, so that the chromaticity and luminance that can be finally recognized by the observer can be adjusted.

In the above configuration, the operation will be described. The molecular orientation directions of the incident light side and the outgoing light side of the liquid crystal cell 14 are set to form an angle θ with respect to the horizontal axis, and the polarization of the incident side polarizing plate is set. The axis (transmission axis) is provided in accordance with this direction. By arranging so that the angle between the neutral axis of the λ / 2 plate and the polarization axis of the incident side polarizing plate becomes θ / 2,
The direction of the polarization axis of the incident side polarizing plate is the P axis of the dichroic mirror.
It can be matched to the polarization direction. Therefore, by arranging the λ / 2 plate 10 in this manner, light transmitted through the incident-side polarizing plate and used by the liquid crystal panel is transmitted to the dichroic mirror P
An optical image can be formed as color light of a polarization component.

On the other hand, by arranging the angle between the neutral axis of the λ / 2 plate and the polarization axis of the incident side polarizing plate to be (90 ° + θ) / 2, the polarization axis direction of the incident side polarizing plate Can be made to coincide with the S polarization direction of the dichroic mirror.
By arranging the λ / 2 plate in this manner, an optical image can be formed by using light transmitted through the incident-side polarizing plate and used in the liquid crystal panel as S-polarized light of the dichroic mirror. Therefore, the neutral axis of the minimum λ / 2 plate is θ with respect to the horizontal axis.
By rotating the liquid crystal panel 14 so that it can be arbitrarily set in the range of / 2 to (90 degrees + θ) / 2, the liquid crystal panel 14 can use color light in the range of the P-polarized light component to the S-polarized light component. It is possible to adjust.

With the above configuration, the present invention can easily realize desired adjustment even if the spectral characteristics of the light source 3 and the spectral transmittance characteristics of the dichroic mirror 5 vary.

(Embodiment 2) Another embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a configuration diagram of the image display device of the present invention.

A projection engine 30 is incorporated in the main body 31 of the liquid crystal projector. An image formed on the liquid crystal panel 16 in the engine is enlarged and projected by the projection lens 21 and projected on the surface of the screen 18. A guide section 35 is arranged on the front surface of the projection lens 21 in parallel with the projection engine 30.
The brightness sensor 36 is configured to slide left and right.

A composite video input signal terminal (1) 32 and an RGB input signal terminal (2) 37 are provided on the rear surface of the liquid crystal projector main body 31 and a data receiving section for exchanging information for equalizing luminance and chromaticity of a plurality of screens. 38 and a data transmission unit 39. In this embodiment, two vertical units × two horizontal units
A description will be given of a four-screen multi-vision system. However, as long as there are at least two or more, the same implementation can be performed in a system of one vertical × two horizontal or three vertical × four horizontal.

FIG. 4 is a configuration diagram of the projection engine 30 built in the main body 31 of the liquid crystal projector. Light emitted from the metal halide lamp 1 is converted into parallel light by the parabolic mirror 2. The parallel light from the light source 3 is blocked by the ultraviolet / infrared cut filter 4 from transmitting ultraviolet and infrared rays to the front surface, and then enters the color separation means 8. Color separation means 8
Separates white light from a light source into blue, green, and red color lights by a blue reflection dichroic mirror 5 and a green reflection dichroic mirror 6. Blue separated by the color separating means 8,
The green and red color lights pass through the field lens 9 and pass through λ /
The light is incident on the two plates 10, 11 and 12. λ / 2 plate 10, 1
Light emitted from 1 and 12 is incident on the liquid crystal panel 16 to transmit a display image on the liquid crystal panel 16. Photosynthesis means 24
Then each display light is reflected by green dichroic mirror 2
In step 2, the blue light and the green light are combined, and then red, blue, and green are combined in the red reflection dichroic mirror 23. Finally, the display image of each liquid crystal panel 16 is enlarged and projected using the projection lens 21.

FIG. 5 is a system diagram of the rear surface of the liquid crystal projector in the four-screen multi-vision system according to the embodiment of the present invention.

The signal from the data transmitter 39 of the reference projector A is input to the data receiver 38 of the projector D, and the signal of the data transmitter 39 of the projector D is transmitted to the data receiver 38 of the projector C.
Is input to the data receiving unit 38 of the projector B, and the signal of the data transmitting unit 39 of the projector B is input to the data receiving unit 38 of the projector A, so that the reference projector can recognize the luminance information of all the projectors. It has become. As is apparent from this system diagram, the reference projector is the same for all projectors. Although not shown, a dip switch or the like is provided on the projector body to determine which projector is to be used as the reference. Can be done.

Next, a method of a luminance / chromaticity detecting means, a chromaticity correcting means, a means for transmitting / receiving luminance information, and a luminance correcting means will be described with reference to FIGS.

First, the power button of the liquid crystal projector main body 31 (not shown) is turned on, and the lamp 1 is turned on. Since the luminance and chromaticity of the lamp 1 are not stable for 2 minutes after the lighting, the measurement is not performed. However, the luminance / chromaticity sensor 36 is moved to the center of the projection lens along the guide 35, and the internal test signal is output. To sequentially project a 100% white signal and a red, blue, and green monochromatic 100% signal. After a lapse of 2 minutes, the luminance / chromaticity sensor 36 is operated to perform measurement. Next, the data transmission unit 3 of the projector A set as the reference projector
Then, a chromaticity / luminance information request signal is transmitted so as to loop from 9 to all projectors. The received projector D adds the identification code 11 (binary number) of the projector D to the header of the chromaticity / luminance information measured in advance, and transmits the data from the data transmission unit 39 of the projector D to the data reception unit 38 of the projector C.

Similarly, the projector C receives the data of the projectors D and C from the data transmission unit 39 of the projector C by adding the identification code 10 (binary number) of the projector C to the header of the chromaticity / luminance information. To the unit 38. Similarly, the projector B also includes the identification code 01 of the projector B in the header of the chromaticity / luminance information.
The data of the projectors D, C, and B are transmitted from the data transmission unit 39 of the projector B to the data reception unit 38 of the projector A with the addition of (binary number). The reference projector A determines the lowest luminance value including the chromaticity luminance data of itself and the optimum chromaticity value. Next, the reference projector A transmits the identification code of the projector to be corrected and the correction data after the identification code 11111 (binary number) indicating the correction. The received projector adjusts the amplitude of the input level to perform luminance correction, and at the same time,
By rotating the motors 1 and 12 by motor control, the liquid crystal panel 16 can use the color light in the range of the P-polarized light component to the S-polarized light component, and the chromaticity of a plurality of units can be uniformly adjusted.

As described above, even if there is a variation in the spectral characteristics of the light source lamp 1 in the projection engine 30 or a variation in the spectral transmittance characteristics of the dichroic mirror, the polarization axis selecting means by the λ / 2 plate is rotated to obtain the brightness and color. The degree can be automatically adjusted, and the brightness and chromaticity of the entire screen composed of a plurality of projectors can always be made uniform. Further, when the power is turned on or when the user adjustment is started, the projection light emitted from the projection lens 21 is detected by sliding from the left or right or up and down (not shown).
Is not projected on the screen surface and the projection lens 21
Since it is possible to detect the direct light from the sensor 36, the detection accuracy of the sensor 36 can be improved.

[0031]

As is apparent from the above description, the image display device of the present invention can be used to convert the light source and the white light from the light source into P and S light sources.
Consists of a color separation unit that separates red, blue, and green color components with a dichroic mirror set between optical characteristics when using each polarized light, and a light valve that can modulate each separated color light In the image display device, a polarization axis selecting means for continuously changing the polarization direction is provided between the color separation means and the light valve, and the polarization axis selecting means is continuously changed. Thus, since the color light in the range from the P-polarized component to the S-polarized component can be used, the chromaticity of the image display device can be easily adjusted. Therefore, even if there are variations in the spectral characteristics of the light source and the spectral transmittance characteristics of the dichroic mirror, the polarization axis can be adjusted to an arbitrary chromaticity by the polarization axis selecting means.

Further, according to the present invention, a light source and white light from the light source are separated into red, blue, and green color components by a dichroic mirror set between optical characteristics when P and S polarized lights are used. In an image display device including a color separation unit and a light valve that can modulate each of the separated color lights, a polarization axis selection unit that can continuously change a polarization direction between the color separation unit and the light valve. Means for modulating the color-separated color light by a light valve, and then projecting the color light by a color combining means and a projection lens. The chromaticity and luminance of the projected light can be continuously adjusted.

Further, the present invention comprises a polarization axis selecting means for changing the polarization direction between the light source and the light valve, and automatically changes the polarization direction by the polarization axis selecting means when an input signal is switched. It has a feature that it can be converted to a desired polarization direction when each input signal is switched in accordance with an input signal that emphasizes chromaticity or an input signal that emphasizes luminance.

According to another aspect of the present invention, there is provided an image display apparatus configured by combining a plurality of units, wherein a means for detecting chromaticity of projection light emitted from the projection lens is provided based on chromaticity information of the detected light. A rotatable λ / 2 plate that is optimal for the wavelength of the color light incident on each light valve and enables continuous conversion of the polarization direction. Even if there is a variation due to the characteristics and the spectral transmittance characteristics of the dichroic mirror, it has the characteristic that it can be adjusted to any chromaticity by the polarization axis selecting means based on the detected result, and the industrial value of the present invention is extremely high There is something great.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image display device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a spectral transmittance characteristic of a dichroic mirror according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of an image display device according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a projection engine according to a second embodiment of the present invention.

FIG. 5 is a transmission / reception system diagram in a four-screen multi-vision system according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp 2 Parabolic mirror 3 Light source 4 Ultraviolet / infrared cut filter 5, 6, 7, 22, 23 Dichroic mirror 8 Color separation means 9 Field lens 10, 11, 12 λ / 2 plate 13, 15 Polarizer 14 Liquid crystal cell Reference Signs List 16 liquid crystal panel 18 screen 21 projection lens 24 color synthesizing means 25, 26 mirror 30 projection engine 31 projector main body 32 input signal terminal 1 35 guide unit 36 chromaticity and luminance sensor 37 input signal terminal 2 38 data transmission unit 39 data reception unit 41 Flat micro lens

Claims (8)

[Claims] 1. A light source, wherein white light from the light source is red,
In an image display device including a color separation unit that separates blue and green color components and a light valve that can modulate each of the separated color lights, a polarization direction is provided between the color separation unit and the light valve. An image display device comprising: a polarization axis selecting unit that enables continuous conversion of light. 2. A light source, wherein white light from the light source is red,
Color separation means for separating blue and green color components, polarization axis selection means for continuously converting the polarization direction, a light valve capable of modulating the color-separated color light, color synthesis means, projection An image display device comprising: a lens. 3. The image display device according to claim 1, wherein the color separation means is a dichroic mirror arranged obliquely to incident light. 4. The image display device according to claim 3, wherein the optical characteristics required of the dichroic mirror are set between the optical characteristics when the P and S polarized lights are used. 5. An image display apparatus comprising a light source, a light valve, and a projection lens, further comprising: a polarization axis selecting unit between the light source and the light valve, the polarization axis selecting unit capable of changing a polarization direction. An image display device for automatically changing the polarization direction according to switching of an image signal captured by the light valve. 6. An image display apparatus comprising a light source, a plurality of projection display apparatuses each including a light valve and a projection lens, and means for detecting chromaticity of projection light emitted from the projection lens. An image display device, comprising: a polarization axis selecting means for continuously changing a polarization direction based on the chromaticity information of the detected light. 7. The polarization axis selecting means is a λ / 2 plate which is optimal for the wavelength of the color light incident on each light valve. Image display device. 8. The polarization axis selecting means is configured to be rotatable so that the polarization axis can be continuously converted.
The image display device as described in the above.