JPH04367836A - Liquid crystal light valve lighting optical system and liquid crystal projection television using the same - Google Patents

Abstract

PURPOSE:To uniformly light a light crystal light valve without any illuminance irregularity nor color irregularity by composing an integrator of a lens member which has an opening in a shape proportional to the aspect ratio of a liquid crystal light valve. CONSTITUTION:A condenser lens 4 consists of a 1st lens group 4a arranged right behind the integrator 3 and a 2nd lens group 4b arranged right before the liquid crystal light valve 5. The 1st lens group 4a is arranged at a secondary light source image position formed by the integrator 3 and the light-source side focus position of the 2nd lens group 4b is set at the secondary light source image position. Luminous flux emitted by a light source 2 is reflected by a parabolic mirror 1 to become parallel luminous flux 7, which is made incident on the integrator 3 to form a secondary light source image 6. Then the light passes through the condenser lens 4 to irradiate the liquid crystal light valve 5. Thus, respective secondary light source images are formed with light beams emitted from different parts of the light emission body of the light source 2 and put on the liquid crystal light valve one over another by the condenser lens, so light utilization efficiency is improved more.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a liquid crystal light valve illumination optical system for illuminating a liquid crystal light valve with high uniformity and high efficiency, as well as a liquid crystal light valve illumination optical system, a liquid crystal light valve, a projection lens, and a screen. This relates to a liquid crystal projection television that is configured with a

0002

2. Description of the Related Art In a liquid crystal projection television, the characteristics of the liquid crystal light valve illumination optical system have a great effect on the image quality of the image enlarged and projected onto the screen. In conventional illumination optical systems, the uneven brightness and color of the light emitter of the light source are directly superimposed on the projected image, significantly impairing the image quality. In order to solve this problem, in the prior art, for example, the lamp arc tube used as the light source is frosted to diffuse the light, thereby improving the image quality.

0003

[Problems to be Solved by the Invention] Liquid crystal projection televisions require an illumination optical system that is free from uneven illuminance and color and has high light utilization efficiency. It is very difficult to make the illuminance distribution and color distribution of the light emitter of the light source uniform. However, in order to solve this problem with the light source, for example, if the lamp arc tube is frosted to diffuse the light, the light utilization efficiency will be significantly reduced, resulting in a dark image.

[0004] The present invention solves the above problems.
The present invention provides a liquid crystal light valve illumination optical system that has high illuminance uniformity, high color reproducibility, and high light utilization efficiency.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the liquid crystal light valve illumination optical system of the present invention includes a reflecting mirror, a light source, an integrator that forms a plurality of secondary light source images, and a condenser. - The integrator is formed of a plurality of members having an aperture proportional to the aspect ratio of the liquid crystal light valve, and the condenser lens is connected to the first lens group close to the integrator and the liquid crystal light valve. It consists of a second lens group close to the light valve.

[0006]

[Operation] The liquid crystal light valve illumination optical system of the present invention can achieve highly uniform illumination performance by using the integrator that forms a plurality of secondary light source images as described above. The reason for this is that each secondary light source image is formed by light emitted from different parts of the light emitter of the light source, and the light emitted from each secondary light source image is further superimposed on the liquid crystal light valve by a condenser lens. This is because that. Therefore, there is no need for frosting the lamp arc tube, and the light utilization efficiency is also increased. Furthermore, by making the aperture shapes of the multiple members forming the integrator proportional to the aspect ratio of the liquid crystal light valve, almost no light passes through the outside of the display area of the liquid crystal light valve, improving light utilization efficiency. Improve further.

As a result, a highly efficient liquid crystal light valve illumination system without color unevenness or illuminance unevenness can be realized.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal light valve illumination optical system according to an embodiment of the present invention and a liquid crystal projection television using the same will be described below with reference to the drawings.

(FIG. 1) is a configuration diagram showing one embodiment of the liquid crystal light valve illumination optical system of the present invention. In FIG. 1, 1 is a reflecting mirror, 2 is a light source, 3 is an integrator, 4 is a condenser lens, and 5 is a liquid crystal light valve. The reflecting mirror 1 is composed of a spherical mirror, a parabolic mirror, an ellipsoidal mirror, or the like. As the light source 2, a metal halide lamp, a halogen lamp, a xenon lamp, or the like is used. The integrator 3 is composed of a bundle of a plurality of lens members 3a, 3b,...
A plurality of secondary light source images 6a, 6b, . . . are formed. The condenser lens 4 consists of a first lens group 4a disposed immediately after the integrator 3 and a second lens group 4b disposed immediately before the liquid crystal light valve 5.

In one embodiment, the reflecting mirror 1 is a parabolic mirror, and a light source is placed at its focal point. The first lens group 4a of the condenser lens 4 is arranged at the secondary light source image position formed by the integrator 3, and the second lens group 4a of the condenser lens 4
The light source side focal position of the lens group 4b is made to coincide with the secondary light source image position. The light beam emitted from the light source 2 is reflected by a parabolic mirror to become a parallel light beam 7, which enters the integrator 3 and forms secondary light source images 6a, 6b, . . . . Thereafter, the light passes through the condenser lens 4 and illuminates the liquid crystal light valve 5. In this way, the light emitted from different parts of the light emitting body of the light source 2 forms the secondary light source images 6a, 6b, . Since the light is superimposed on the liquid crystal light valve 5, uneven illuminance and color of the light emitting part of the light source 2 do not appear on the liquid crystal light valve 5.

FIG. 2 shows a sectional view of the integrator 3. The integrator 3 includes a plurality of lens component members 3a,
3b, . . . , and the opening of each member has a vertical dimension h and a horizontal dimension w. By adjusting this size ratio h/w to the aspect ratio of the liquid crystal light valve 5, the light utilization efficiency is improved. That is, for NTSC image display, h/w=
3/4, and for high-definition image display,
Let h/w=9/16. As a result, only the image display portion of the liquid crystal light valve 5 can be efficiently illuminated without wasting the luminous flux.

FIG. 3 shows a configuration diagram of a liquid crystal projection television using the liquid crystal light valve illumination optical system of the present invention. In FIG. 3, 11 is a liquid crystal light valve illumination optical system of the present invention, 12 is a field lens, 13 is a liquid crystal light valve, 14 is a projection lens, and 15 is a screen. The field lens 12 is used to effectively cause the light emitted from the liquid crystal light valve illumination optical system 11 and illuminating the effective display area 13a of the liquid crystal light valve 13 to reach the entrance pupil 14a of the projection lens 14. The light emitted from the illumination optical system 11 is controlled by a light shutter of a liquid crystal light valve, and the image is magnified by a projection lens 14 and projected onto a screen 15. Due to the configuration of the present invention, the liquid crystal light valve illumination optical system 11 uniformly illuminates the liquid crystal light valve 13 without uneven illuminance or color, so that the screen
The image enlarged and projected onto the screen is also homogeneous and of good quality.

[0013]

[Effects of the Invention] As described above, by satisfying the configuration and configuration conditions of the present invention, it is possible to realize a liquid crystal light valve illumination optical system that can uniformly illuminate a liquid crystal light valve without uneven illuminance or color unevenness. By combining the liquid crystal light valve illumination optical system, liquid crystal light valve, projection lens, and screen of the present invention, a liquid crystal projection television with uniform and high image quality can be realized.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a liquid crystal light valve illumination optical system according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an integrator.

FIG. 3 is a schematic configuration diagram of a liquid crystal projection television according to an embodiment of the present invention.

[Explanation of symbols]

1 Reflector 2 Light source 3 Integrator 3a, 3b Integrator component 4 Condenser lens 4a First lens group of condenser lens 4b Second lens group of condenser lens 5 Liquid crystal light valves 6a, 6b Secondary light source Image 7 Luminous flux 11 Liquid crystal light valve illumination optical system 12 Field lens 13 Liquid crystal light valve 13a Effective display area 14 of the liquid crystal light valve Projection lens 14a Entrance pupil 15 of the projection lens Screen

Claims (4)

[Claims] 1. The integrator is composed of a reflecting mirror, a light source, an integrator that forms a plurality of secondary light source images, and a condenser lens, and the integrator has an aperture having a shape proportional to the aspect ratio of a liquid crystal light valve. A liquid crystal light valve illumination device comprising a plurality of lens members having the same structure, and the condenser lens comprising a first lens group close to the integrator and a second lens group close to the liquid crystal light valve. Optical system. 2. The liquid crystal light valve illumination optical system according to claim 1, wherein the reflecting mirror is a parabolic mirror, and the light source is arranged at the focal point of the reflecting mirror. 3. The first lens group of the condenser lens is arranged at the secondary light source image position formed by the integrator, and the light source side focal position of the second lens group is located close to the secondary light source image position. 2. A liquid crystal light valve illumination optical system according to claim 1. 4. The integrator is composed of a reflecting mirror, a light source, an integrator that forms a plurality of secondary light source images, and a condenser lens, and the integrator has an aperture having a shape proportional to the aspect ratio of the liquid crystal light valve. a liquid crystal light valve illumination optical system comprising a plurality of members having the condenser lens, a first lens group close to the integrator, and a second lens group close to the liquid crystal light valve; A liquid crystal projection television characterized by comprising a bulb, a projection lens, and a screen.