JPH0414031A - Liquid crystal type video projector - Google Patents

Abstract

PURPOSE:To use a sub channel while keeping the brightness of a main channel by splitting a projected light beam into two by; a deflecting beam splitter. CONSTITUTION:In this liquid crystal projector, the projected light beam from a light source 3 is split into two deflected light beams by the deflecting beam splitter 4, and one of the deflected light beams is transmitted to the main chan nel system 1 and the other is transmitted to the sub channel system 15. After the deflected light beam is turned into red, blue and green image light beams through red, blue and green reflection dichroic mitrors 5, 8, 9, and 13 and liquid crystal panels for red, blue and green 7, 10 and 11, the light beams pass through a projection lens 14 and are synthesized on a screen S in the system 1. In the system 15, an image 21, etc., is projected on the screen S by allowing the light beam to pass through a mirror 16, a liquid crystal panel 17 for monochrome and a projection lens 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal projector using a liquid crystal panel.

[Summary of the Invention] The present invention separates projection light from a light source into red, green, and blue using a dichroic mirror, and displays each of the divided projection lights on a screen via a liquid crystal panel for each monochrome and a projection lens. In a liquid crystal projector configured to project upward, the projected light from the light source is split into two by a polarized beam splitter, one polarized light of the projected light is supplied to the dichroic mirror, and By configuring the other polarized light to be projected onto the screen via a single liquid crystal panel and a projection lens, the image displayed on each single color liquid crystal panel can be displayed on the screen in whole or in part. This is a liquid crystal projector that can display images overlapping images.

[Prior Art] A television receiver that simultaneously projects images of two different channels on the image receiving surface of a single cathode ray tube has been commercialized. In such a receiver, a part of the video signal of the main channel is erased, the scanning lines of the video signal of the sub-channel are extracted and stored at appropriate intervals, and the video signal of the sub-channel stored during the erased period mentioned above is stored. I am trying to insert it and display it. In this case, the main channel image is a large screen, and the sub channel image is a small screen, and both screens are formed by being simultaneously scanned with an electron beam. This type of image effect is generally called ``picture-in-picture'', but in order to produce this type of image effect, it is necessary to use not only a television receiver but also a system based on the video signal (
A projection type video display device that has a video source that obtains video information as a reproduced image using a cathode ray tube, and projects the reproduced image onto a screen using a lens or a magnifying glass to display an enlarged image, commonly known as a ``video projector.'' What can be achieved by developing the technology of equipment called
For example, it has been proposed in Japanese Patent Publication No. 59-11306 ``Projection Type Multiple Image Synthesizer''.

[Problem to be solved by the invention] However, in the latter case, cathode ray tubes for red, green, and blue are required in the main channel system, and at least one cathode ray tube is required in the subchannel system, which makes the entire device It is heavy and large, has a complicated electronic circuit configuration, and has the disadvantages that it is difficult to adjust color matching.

[Means to solve the problem]

In order to solve this problem, in the present invention, the video display device for the main/Gekiga channel system is configured with a liquid crystal panel and an optical device,
In particular, the projection light from the light source is deflected into the sub-channel system.
The splitter splits the projected light into two, and one polarized light is supplied to the dichroic mirror in the liquid crystal video projector that constitutes the main channel, while the other polarized light is sent through a single liquid crystal panel and a projection lens. The video projector is characterized in that it is configured so that it is projected onto a screen and displayed on the screen superimposed on the image projected by the main channel liquid crystal video projector.

[Function] According to the above configuration, not only can the entire device be made lighter, more compact, and lower in cost, but also the light projected from the light source is separated by a deflection beam splinter, so it cannot be used in the main channel. You can add a sub-channel while maintaining the same brightness without changing the amount of light being displayed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic plan view of a liquid crystal video projector showing an embodiment of the invention, and FIG. 2 is a diagram showing an example of an image on a screen projected by the projector of the invention. .

In FIG. 1, 1 indicates the main channel system, 2 indicates a three-panel liquid crystal projector, and the optical axis C of the imaging optical system.
Projected light from a light source 3 such as a xenon lamp arranged at the upper rear part is first divided into two polarized lights (P component and S component) by a polarized beam splitter 4. One polarized light (for example, the P component) is separated by a red reflective dichroic mirror 5, and the red light, blue light, and green light are sent to a mirror 6, a red liquid crystal panel 7, and a pair of blue reflective dichroic mirrors 8. 9. After forming red image light, blue image light, and green image light through the liquid crystal panel 10 for blue color, liquid crystal panel 11 for green color, mirror 12, and green reflection dichroic mirror 13, respectively, The images are synthesized on a screen S through a projection lens 14 on an optical axis C.

Note that the center of the liquid crystal panel 7.10.11 is located on the optical axis C of the coupling optical system.

The other polarized light (for example, the S component) is sent to the sub-channel system 15.
The image is projected onto a screen S through a mirror 16, a monochromatic liquid crystal panel 17, and a projection lens 18, and is superimposed on the image screen synthesized by the main channel. For example, as shown in Fig. 2a, a normal landscape image 20 is projected onto the screen S by the projector of the main channel system 1, and an image 21 of a human figure is superimposed thereon by the projector of the sub-channel system 15. be able to.

Also, as shown in Figure 2, while projecting a normal image 20 with the main channel system 1 projector, the sub channel system 1
With the projector No. 5, an image 22 such as the time or teletext news can be projected in one corner of the image 20.

[Effects of the Invention] As described above, according to the present invention, by simply providing a deflection beam splitter and a sub-channel projector,
Other images can be projected onto the same screen without changing the amount of projection light sent to the main channel system and without changing the brightness. Moreover, conventional projectors of this type
Compared to the above, it is easier to adjust color matching, and it is also lighter and more compact, reducing costs.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of a liquid crystal video projector showing an embodiment of the present invention, and FIG. FIG. (Explanation of symbols) 3−−−−−−−−−−−−−−−−−−−−−−−−
1 light source 4−・−−1−−−−−−−−−−−−−−−−
---, - deflection beam splitter 5.8.9---
-----・-Dichroic mirror 7.10S11,
I7-LCD panel

Claims (1)

[Claims] A liquid crystal display configured to separate the projected light from a light source into red, green, and blue using a dichroic mirror, and project each of these separated projected lights onto a screen via a monochromatic liquid crystal panel and a projection lens. In the projector, the projected light from the light source is split into two by a polarized beam splitter, one polarized light of the projected light is supplied to the dichroic mirror, and the other polarized light is projected onto a single liquid crystal panel. A liquid crystal video projector, characterized in that it is configured to project onto the screen via a lens.