JPS62258491A - Projection type color display unit - 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] [Industrial application field] The present invention relates to a configuration f of a projection type color display device.

[Summary of the invention]

In a projection type color display device, the present invention focuses light from a light source into white parallel light, uses a dichroic mirror to separate the white light into three primary colors of light, and uses a lens to project the light into an image display area of a liquid crystal panel. In addition, the lens placed on the light input side of the liquid crystal panel allows the light that has passed through the image display area of the liquid crystal panel to reach the projection lens. It is possible to obtain a bright projected image even with a dark projection lens by adjusting the KLi so that light enters efficiently.

Furthermore, since the projected image is obtained by combining three-color images from the dichroic mirror, it is possible to obtain a clear projected image without color shift in the peripheral area of the image.

[Conventional technology]

Examples of conventional projection type color display devices are explained with reference to Figure 6.The red projection tube 100R and the green projection tube 100G are made of Braun VK coated with red, green, and blue phosphors.
・The image from the blue projection tube 100B is transferred to the three-piece projection lens 101.
A method is known in which a composite image is obtained by projecting the image onto the screen 102.

[Problem that the invention seeks to solve]

In the prior art described above, there is a problem in that color shift occurs due to the positional difference of the projection lens (C) in the periphery of the image displayed on the screen. This requires a large projection tube and a bright lens with a large aperture ratio, resulting in a large trap.

The present invention is intended to solve these problems, and its purpose is to provide a projection system that is capable of producing bright projected images using a small device, and that provides clear images without color shift. The present invention provides a type color display device.

[Means for solving problems]

The projection type color display device of the present invention includes a means for collecting white light emitted from a light source to obtain parallel light, a means for separating the white light into red, green, and blue light, which are the three primary colors of light, and a lens. By means of concentrating light by a thin transistor? In addition to illuminating the display part of the liquid crystal panel that is integrated in a matrix, the light that passes through the display part of the liquid crystal panel is efficiently incident on the projection lens by the I/L lens. With means.

The idea came about when he attempted to obtain a projected image using a single projection lens by combining three-color images.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a projection type color display, and the cabinet 10 has an operation panel 12 that includes terminals and switches for connecting an air inlet 11 for cooling a light source, which will be described later, and an external cabinet. . 20 projection lenses cabinet 1
Although it is more exposed and solid than 0, -? Yabineshito 10
may be housed within.

FIG. 2 is a top view of the projection type color display device, and FIG. 3 is a side sectional view of the projection type color display device, which explains the present invention in detail.

The white light emitted from the light source 21 such as a halogen lamp is
The light traveling backward is condensed by a reflector 22 that reflects the light forward and a condenser lens 23.

Using a condenser lens with a short focal length of 23,
By increasing the solid angle with the light source 21, the light collection efficiency is increased.

By placing the light source 21 at the focal point of the condensing lens 23, the light condensed by the condensing lens becomes parallel light, and the heat rays are reduced by the endothermic filter 24 before color separation is performed.

Color separation is performed by a dichroic mirror, and the red reflective dichroic mirror 25 reflects only the red wavelength component of the light.
The blue reflecting dichroic mirror 26 reflects only the actual wavelength component of the light. The light passes through the red reflecting dichroic Mi-Y-25 and the blue reflecting dichroic mirror, and the guided light becomes light corresponding to the green degree.

The green component light directly illuminates the green light display liquid crystal panel 31G, but the red and blue component light illuminates the red display liquid crystal panel 3 by the first lens 27 having a length t/-1 of the point distance 1111.
Display pixel section 32 of 1R and blue display liquid crystal panel 31B
The light is focused to illuminate only that area. Reflective layer 28.
Reference numeral 29 is for guiding the next light that passes through the dichroic mirror to the liquid crystal panel. Furthermore, unlike the red and blue component lights, the green component light does not have a long optical path and has less loss, so no lens is used to condense the light.

By arranging the silent part of the second lens 30 to be inside or near the projection lens 20, the light transmitted through the display pixel section 32 of the liquid crystal panel efficiently enters the projection lens 20, so that the aperture ratio can be reduced. Even with a small, dark projection lens, you can get a bright image.

Dichroic prisms 53 rectangular prisms with red and blue reflective layers, which have the same performance as a dichroic mirror, are vapor-deposited on the slopes of four dichroic prisms.

Red display LCD panel 31R1 Green display LCD panel 31G
The image from the rear display liquid crystal panel 31B can be reflected or transmitted through the reflective surface of the dichroic prism to obtain a composite image.

The circuit section 54 includes a television circuit, a drive circuit for a liquid crystal panel, a power supply, etc., and a cooling fan 35 exhausts heat generated from the light source 21 to the outside.
-6- FIG. 4 is a W'1 plane view of the liquid crystal panel, and FIG. 5 is an equivalent circuit diagram of the liquid crystal panel, which will explain and explain the liquid crystal panel.

Transparent pixel electrodes 44 are formed in a matrix on the quartz substrate 40, and two thin film transistors 43 are connected across each pixel electrode 44.

The gate line 41 is connected to the gates of the thin film transistors 43 and selects one row of the thin film transistors 43 in a matrix.

A source line 42 is connected to the source of a thin film transistor 43, and an amount of electricity corresponding to one image signal is transferred through the thin film transistor 43 to a capacitor constituted by a pixel electrode 44 and a counter electrode 46.

A transparent counter electrode i46 is formed on the glass substrate 45, and a photoluminescent layer 48 is opaque except for an opening 49 that is opposite to one pixel electrode.
It shines brightly. Normally, if the illumination light enters from the glass substrate 45 side and exits from the quartz substrate 40 side, the influence of light from the thin film transistor 430 can be suppressed.

It is a 50 liter polarizing plate.

By R1ing the thin film transistor 43 as an active element for each pixel, when the thin film transistor 43 is ONL, the display data is connected to the pixel voltage @44 and the counter voltage @4.
Thin film transistor 43 is written to the capacitance of 5y.
When the display data is turned off, the display data is stored in the capacitor in the form of electric charge and functions as a memory, so that a display with good contrast characteristics can be achieved.

〔Effect of the invention〕

As explained and explained above, according to the present invention of the IC, bright illumination can be obtained by focusing light on the display section of the liquid crystal panel using the lens, and the light that passes through the liquid crystal panel can efficiently enter the projection lens. Since the lenses are arranged in this manner, a bright projected image can be obtained even if a small, dark projection lens with a 1 aperture ratio is used.

In addition, since color synthesis is performed using dichroic prism pressure and projected using a single-wooden projection lens, a clear image without color shift can be obtained even at the periphery of the image.

In addition, since the colors of the image are synthesized using a graphical prism and projected using a single large projection lens, it is possible to obtain a clear image with no color shift up to the periphery of the image.

Furthermore, since the display is performed using a liquid crystal panel in which thin film transistors are integrated in a matrix, images with good contrast characteristics can be obtained, the display section can be made smaller, and the entire device can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a projection type color display device. Figure D2 is a top view of the projection type color display device. Figure 3 is a side view of the projection type force→-clothing device. Figure 4 is a cross-sectional view of the liquid crystal panel. Figure 5 is an equivalent circuit diagram of a liquid crystal panel. FIG. 6 is a diagram showing a conventional example. that's all Applicant: Seven Epson Corporation Figure 1

Claims (1)

[Claims] Display by integrating thin film transistors in a matrix 3
In a color display device that illuminates a liquid crystal panel with the three primary colors of light, red, green, and blue, and projects a composite image of the three colors, there is a method for obtaining parallel white light, and a method for converting white light into light. means for separating the light into three primary colors; means for condensing the light with a lens; and means for guiding the light to a projection lens using the lens;
1. A projection type color display device comprising means for synthesizing three-color images.