JPH0443789A - LCD projection display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a projection display device (hereinafter referred to as a liquid crystal projection display device) that enlarges and projects a liquid crystal panel image for color television reception onto a projection screen.

2. Description of the Related Art In recent years, liquid crystal projection display devices have been developed that enlarge and project images on a small liquid crystal panel onto a screen.

FIG. 2 shows the optical system of a liquid crystal projection display device.

The light source 15 is, for example, an image from a color picture tube, and the light emitted from the light s15 passes through a condenser lens 16 and is separated into three primary color lights of red, green, and blue by dichroic ink mirrors 17 and 18. After that, the red light R is reflected by the total reflection mirror 19.
20 and passes through the field lens 23, a red light image is formed on the liquid crystal panel 1.

The green light G passes through the field lens 24 and is displayed on the liquid crystal panel 4.
A green light image is formed. Blue light B is totally reflected mirror 2
1.22, passes through the field lens 25, and a blue light image is formed on the liquid crystal panel 7.

The three primary color images of red, green, and blue formed by three liquid crystal panels are combined by a color composition dichroic ink mirror 1011 and projected onto a projection screen 13 through a projection lens 12 as a color image.

FIG. 3 shows a conventional example of the arrangement of the optical system and the liquid crystal panel after the liquid crystal panel of a liquid crystal projection display on the projection screen. 1, 4.7 are liquid crystal panels for red light, green light, and blue light, respectively, and the three primary color images formed by these are synthesized by dichroic mirrors 10 and 11, and the projection lens 12
A color image is projected onto the projection screen 13 through the. At this time, only the image 14 of the green light on the liquid crystal panel 4 has a different number of reflections on the dichroic mirror than images of other colors, so the images of the red light and the blue light are left and right opposite on the screen.

For this reason, the scanning direction of only the green light liquid crystal panel is driven in left-right reversal.

Problems to be Solved by the Invention In manufacturing liquid crystal panels, liquid crystal is injected through an injection port, but at this time, the liquid crystal injection pressure is different between the injection port and other parts, resulting in changes in the alignment state of the liquid crystal. . Therefore, the transmittance of light especially near the injection port is different compared to other parts, which appears as color unevenness when enlarged and projected. Third
In the figure, 2.26°8 is the injection port for the liquid crystal panel, and 3.27.9
are parts with different light transmittances. The images of areas 3 with different light transmittances on the red light liquid crystal panel and areas 9 with different light transmittances on the blue light liquid crystal panel are both 14 on the projection screen 13 and overlap, but the light transmission on the green light liquid crystal panel is The image of the portion 27 having different ratios becomes 28 on the screen 13. In this way, the brightness difference (1
4 and 28), so in the configuration of Figure 3, screen 1
3 The image above has uneven color.

In view of the above problems, the present invention provides a method for configuring a liquid crystal panel in a liquid crystal projection display device in which color unevenness is less noticeable.

Means for Solving the Problems In order to solve the above problems, in the liquid crystal projection display device of the present invention, the positions of the parts having different transmittances are matched in all the liquid crystal panels forming the color image to be synthesized. Another technique is to place the liquid crystal injection ports of one or more liquid crystal panels at different positions.

Function The liquid crystal projection display device of the present invention is configured such that the injection ports of all the liquid crystal panels constituting the liquid crystal projection display device are aligned on the projection screen, so that the image formed by each liquid crystal panel on the projection screen can be improved. The distribution of brightness unevenness matches, and color unevenness becomes much less noticeable.

Embodiment Hereinafter, a method of constructing a liquid crystal projection display device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of the entire apparatus of the present invention, and FIG. 1 shows the optical system and liquid crystal panel arrangement after the liquid crystal puff of the liquid crystal projection display apparatus of the present invention. 1° 47 is a liquid crystal panel for red light, green light, and blue light, respectively. The three primary color images formed by these are combined by a dichroic ink mirror 10.11, and the projection lens 12 reverses the top and bottom and left and right to project the image on the projection screen. A color image is projected onto 13. At this time, the image on the liquid crystal panel for red light is reversed left and right by the dichroic mirror 10, and the image on the liquid crystal panel for blue light is similarly reversed, but the image on the liquid crystal baffle for green light is transmitted through the lens 12 as is. In order to take a close-up image, the red light and the red light image are left and right opposite on the screen. Therefore, scan driving is performed so that only the liquid crystal display for green light is reversed horizontally.

2.5.8 is the injection port of the liquid crystal panel, and 3 and 6.9 are parts with different light transmittances. The green-filled liquid crystal panel uses a liquid crystal panel in which the injection ports 5 are formed in positions opposite to those for red light and blue light.

Portion 3 with different light transmittance at the injection port position on the liquid crystal panel for red light and portion 9 with different light transmittance on the liquid crystal panel for blue light
Both images are 14 on the screen 13 and overlap. The images of portions 6 with different light transmittances on the liquid crystal panel for green light also become 14 on the screen 13, and the images of the portions with different light transmittances of the three panels overlap. In this way, the positions of the portions (3° 6.9) where the brightness differs between the panels coincide on the screen, so that color unevenness does not occur.

Effects of the Invention As detailed above, the liquid crystal injection ports of one or more liquid crystal panels are arranged differently so that the positions of the portions with different transmittances of all the liquid crystal panels that form the image to be combined are aligned. By using a liquid crystal panel formed at a certain position, even if color unevenness occurs in a liquid crystal projection display device, it is less noticeable.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing the arrangement of each element of a liquid crystal projection display device according to an embodiment of the present invention, FIG. 2 is an optical system layout diagram of the same liquid crystal projection display device, and FIG. 3 is a conventional one. FIG. 2 is an external perspective view showing the arrangement of each element of the liquid crystal projection display device. 1... Liquid crystal panel for red light, 2... Liquid crystal panel inlet for red light, 4... Liquid crystal panel for green light, 5... Liquid crystal panel for green light. LCD panel inlet, 7
. . . Liquid crystal panel for blue light, 8 . . . Liquid crystal panel inlet for blue light, 13 . . . Projection screen. Name of agent: Patent attorney Shigetaka Awano (1 person) Projection screen diagram

Claims (1)

[Claims] In a liquid crystal projection display device using a plurality of liquid crystal panels, the scanning direction of one or more of the liquid crystal panels is driven to be different from the scanning direction of other liquid crystal panels, and the liquid crystal injection port of the liquid crystal panel is 1. A liquid crystal projection display device, characterized in that the neighboring projected images of are configured to coincide on a projection screen.