JPH02257190A - Projection type display device - Google Patents

Abstract

PURPOSE:To reproduce the color tone of an original picture by applying both in-plane brightness correction and inter-color beam brightness correction to plural transmission type light valves which modulate three different color beams. CONSTITUTION:Both the in-plane brightness correction and the inter-color beam brightness correction are applied to transmission type light valves 19 to 21. Even if the intensity distribution of light beams which are made incident on the three transmission type light valves 19 to 21 for R, G and B varies with the type of the valves, the injection intensity of each light valve plane is made equal by the in-plane brightness corrections 13 to 15 and the intensity of light coming out of light valves 19 to 21 are balanced with each other by the inter- color brightness corrections 16 to 18. Thereby, the image of the same color tone as that of the original can be displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a projection type display device for displaying video images, computer images, etc. In particular, the present invention relates to a projection type display device using a transmission type light valve, which has excellent contrast and can realize a compact size.

[Prior Art] As a conventional projection type display device using a transmission type light valve, one having a configuration as shown in Fig. 1 has been proposed. (
SID87 DIGEST 75p) A version with 70,400 pixels is planned to be commercialized.

[Problem to be Solved by the Invention 1] However, in the prior art described above, the intensity distribution of light incident on the three transmission light valves for R, G, and B is different from that of the three transmission light valves. This caused the following problems:

That is, if the incident light intensity distribution is as shown in FIG. 3, for example, the entire image projected onto the screen will be reddish. When displaying an all-white image, the center will have a slight reddish tinge, and the periphery will become more reddish.Even if white balance is achieved in the center using optical means, Even if normal color reproduction is achieved in the edges, the edges will look reddish.Furthermore, if white balance is done in the edges, the center will become bluish.As a result, the original human-generated image It was only possible to display images with different color tones.

Therefore, the present invention has been made to solve such problems.

[Means for Solving the Problems] A projection type display device of the present invention includes a plurality of different transmission type light valves, in which each of the plurality of transmission type light valves has an in-plane luminance. It is characterized by performing correction and inter-color luminance correction.

[For use] The projection type display device configured as described above is, for example, R
Even if the intensity distribution of the light incident on the three transmissive light valves for G, G, and B is different for each of the three transmissive light valves, in-plane luminance correction can be used to adjust the intensity distribution within the plane of each light valve. In order to equalize the intensity and balance the intensity of the emitted light between each light valve by adjusting the brightness between the brown lights, it is possible to display an image with exactly the same tone as the original human image. (In other words, when it is desired to display all self-portraits, all self-portraits are displayed.) Hereinafter, the present invention will be described in detail using examples. However, the present invention is not limited to the following examples.

(Example 1) FIG. 1 is a diagram without showing the configuration of an optical system of a projection type display device of the present invention. 1 light source. 2 is a guikroic mirror. 3 is a reflective mirror. 4 is a transparent light bulb. 5 is a guichroic prism. 6 is a projection lens. 7 is a screen. (SID87 DIGEST 75p Spit≦Robe) FIG. 2 is a diagram for explaining the in-plane luminance correction means and the inter-color luminance correction means of the projection display device of the present invention. 8 is an image input terminal. 9 is an image signal containing a mixture of color signals and luminance signals.
-Distributor for distribution to valves. Reference numeral 10 denotes an R driver that distributes the R image signal supplied from the distributor between the R transmission type light valves 19. Similarly, 11 is a driver for G. Similarly] 2 is a driver for B. ] 3.14.15 are in-plane brightness correction means for R, G, and B, respectively. 16,]
7 and 18 are inter-color luminance correction means. 19 is the light bulb for R. 20 is for G lie 1~valve.

21 is a B-use valve.

Here, for reference, the case of a conventional projection type display device will be described. As shown in FIG. 8, it can be seen that there is no in-plane brightness correction means of 13.14.15 and intercolor brightness correction means of 16.17.18.

Next, the functions and effects of the in-plane brightness correction means and the inter-color brightness correction means of the present invention will be explained using FIGS. 3 to 6.

First, as mentioned in the operation section of the projection display device having the configuration shown in FIG. There are two different transmission type light valves, as shown in Figure 3. If the image is displayed on the screen without any correction, color unevenness will occur. Although it is possible to reduce color unevenness to some extent using optical means, color unevenness still remains, and color unevenness becomes more noticeable as screens become larger, higher definition, and of higher quality. I'm especially concerned about uneven coloring around the edges.

Therefore, by using the in-plane brightness correction means 13 to 15 and the intercolor brightness correction means 16 to 18 in Fig. 2, a signal that cancels out the incident light intensity distribution is electrically added to the original image signal. I did it. In other words, within the plane of each transmissive light valve, the transmittance is greatly reduced at pixels where the intensity of incident light is strong, and the transmittance is not reduced too much at pixels where the intensity of incident light is not so strong. It is. (See Figures 4 and 5.) As a result, when an all-white state is to be displayed, the intensity of the emitted light from each transmissive light valve is uniform throughout the plane, and the intensity is Since it is balanced with a transmission type lie 1-valve,
The entire selfview was displayed on the screen. (FIG. 6) In other words, the tone of the original image is completely reproduced. In fact, it has been confirmed that no matter what color tone you input, the image will be reproduced on the screen in exactly that color.

Further, in FIG. 2, the configuration of the present invention was explained using a simple block diagram of a method for correcting an image signal from a driver using an in-plane luminance correction signal and an inter-color luminance correction signal. A system may also be used in which the in-plane luminance correction signal and the inter-color luminance correction signal shown in the block diagram in FIG. 7 are added to the signal from the distributor and supplied to the driver. Also, other methods may be used. In short, it is sufficient that the in-plane luminance correction signal and the inter-color luminance correction signal are reflected in the drive signal that directly drives the FT.

[Effects of the Invention 1] The projection type display device of the present invention includes a plurality of different transmission type light valves, and each of the plurality of transmission type light valves has an in-plane brightness correction and a color difference correction method. Since the brightness correction is applied, the image displayed on the screen has no color unevenness, and the color tone of the original image can be completely reproduced.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an optical system of a projection type display device of the present invention. FIG. 2 is a block diagram for explaining the in-plane brightness correction means and the inter-color brightness correction means of the projection display device of the present invention. FIG. 3 is a diagram showing the intensity distribution of light incident on each transmission type light valve. ((a) is red, (b) is green, and (c) is blue) Figures 4 and 5 show the in-plane luminance correction signal and inter-color luminance correction signal for an all-white screen. FIG. 3 is a diagram showing the transmittance of each transmission type light valve when ((a) is red, (b) is green, and (C) is blue) Figure 6 shows each case when an in-plane luminance correction signal and an intercolor luminance correction signal are given on an all-white screen. FIG. 3 is a diagram showing the intensity distribution of light emitted from a transmission type light valve. ((a) is red, (b) is green, and (c) is blue) FIG. 7 is a block diagram different from FIG. 2 of the projection type display device of the present invention. FIG. 8 is a block diagram of a circuit for driving each transmission type light valve of a conventional projection type display device. Light source, guichroic mirror, transmission type light valve, guichroic prism projection lens, screen, image input terminal, driver for distributor R, driver for G, driver for B, in-plane brightness correction means for R, for G In-plane brightness correction means In-plane brightness correction means for B, inter-color brightness correction means for R, inter-color brightness correction means for G, inter-color brightness correction means for B 1 ・ 2 ・ ・ 6 ・ 9 ・ 10 ・ ・ Book 12 13, 14, 15... Transmissive light valve for R Transmissive light valve for G Transmissive light valve for B Transmissive light 1 to bulb ・Transmissive light valve for R with each brightness correction working.・Transmissive light valve for G with each brightness correction working. 24... Transmissive light valve for B with each brightness correction working. Applicant Seiko Epson Co., Ltd. Agent Patent Attorney Kisanbe Suzuki (1 other person) - HiO + Shi (α) (C) (C) 1st Ward (θ) (Tono (C) 1st Round Map)

Claims (1)

[Claims] In a projection type display device including a plurality of transmission type light valves that modulate three different color lights, the plurality of transmission type light valves are each subjected to in-plane luminance correction and intercolor luminance correction. A projection type display device.