Rear projection display

Abstract

The present invention provides an illuminating device and a projection type video display device that do not require a dichroic prism, and that generate systems for each color of video light independently, thereby enabling optimization of each generating system and improvement in assembly. Each video light projection unit is composed of an LED array, a columnar integrator, a liquid crystal display panel and a projection lens. The projection optical axes of the projection lenses in each video light unit are parallel to each other. The red video light projection unit has an LED array that emits light in the red wavelength band, the green video light projection unit has an LED array that emits light in the green wavelength band, and the blue video light projection unit has an LED array that emits light in the blue wavelength band. The video lights of various colors obtained through the liquid crystal display panel are magnified and projected by the projection lens, and projected on the screen, so that the video lights of various colors overlap on the screen to display full-color video.

Description

technical field [0001] The present invention relates to a rear projection type video display device. Background technique [0002] There is a projection type video display device (JP-A-2004-220015), which has three color light sources that respectively emit light of three primary colors, and light modulation of each color light from each color light source through a light valve, and a dichroic prism (dichroic prism) synthesizes video lights of various colors obtained through the light modulation, and projects the full-color video light obtained through the synthesis through a projection lens. In addition, it has also been proposed that each color light obtained by color-separating white light from one light source is light-modulated by a liquid crystal display panel, and that each color video light obtained by the light modulation is projected through three projection lenses, A liquid crystal rear projection television in which video lights of various colors are superimpose...

AI Technical Summary

Problems solved by technology

[0003] However, in the technique of the former patent document, since the video light of each color is synthesized by a dichroic prism, the video light of a certain wavelength band is cut off and high brightness cannot be achieved, and there are various disadvantages.

In addition, in the technique described in the latter patent document, it is necessary to separate the white light from one light source, and in this color separation, there is a disadvantage that the distances from the light source to the liquid crystal display panel cannot be made equal for all colored lights.

In addition, the projection system of each color video light is not independent in the form of including a light source, so it cannot be unitized (integrated) in the form of a light source included in the projection system of each color video light. In addition, it is difficult to project the various colors of video light system for optimal design or optimal control of light sources

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