JP2567718B2 - LCD projector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid crystal projector that irradiates an LCD panel with light from a light source and projects an image of the LCD panel on a screen in an enlarged manner, and particularly irradiates the LCD panel. The present invention relates to a liquid crystal projector in which light on a screen is averaged and the image on the LCD panel is projected brightly on a screen.

“Prior Art” Conventionally, in this type of liquid crystal projector, a high-luminance metal halide lamp, a xenon lamp, or the like has been used as a light source.

Then, the LCD panel was uniformly illuminated by the light from the light source.

[Problems to be Solved by the Invention] Metal halide lamps, xenon lamps, and the like as light sources of liquid crystal projectors are spherical light sources or tubular light sources, not surface light sources.

Therefore, when the LCD panel was irradiated with light, the brightness was different between the central part and the peripheral part.

A diffuser plate was used to eliminate such a variation in brightness, but this diffuser plate lowered the transmittance.

The present invention has been made in view of the above points, and an object of the present invention is to provide a liquid crystal projector capable of irradiating an LCD panel with uniformized light, like the surface light source.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the present invention, in a liquid crystal projector for projecting an image of an LCD panel on a screen with light from a light source, the light from the light source of the LCD panel is projected. Condensing horizontal light diffusing means for condensing and uniformly diffusing on a horizontal line, synchronizing means for synchronizing the light emitted from the converging horizontal diffusing means with the input video signal, and synchronizing light is vertically deflected. Then, a deflection means for irradiating the LCD panel is provided.

[Operation] In the embodiment of the present invention, the light emitted from the light source 1 is condensed in one direction by the cylinder lens 21, passes through the optical fiber 22 and the light diffusing plate 23, and is formed into a line shape that matches the display horizontal direction. It is converted into uniform brightness and emitted to the light deflector 3.

The light incident on the light deflector 3 is scanned in the vertical direction,
The light scans the LCD panel.

The LCD panel is driven by the liquid crystal driving means 8, and an image according to the content of the video signal from the signal processing means 7 is displayed.

The image passes through the projection lens 5 and the projection screen 6
Is enlarged and projected.

“Example” Next, an example of an embodiment of the liquid crystal projector according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a system configuration diagram of a liquid crystal projector according to the present invention.

In FIG. 1, the light emitted from the light source 1 such as a metal halide lamp is condensed by the converging horizontal light diffusing means 2.
The light is converted into a line-shaped uniform brightness that matches the horizontal display direction, and is output to the light deflector 3.

The light incident on the light deflection means 3 is vertically scanned there, and the scanned light optically scans the LCD panel surface of the liquid crystal display means 4.

This optical scanning is synchronized with the video synchronizing signal from the signal processing means 7 (the same means 9) and repeats the scanning from the top to the bottom of the LCD panel and from the top to the bottom.

The liquid crystal display means 4 is composed of an LCD panel, is driven by the liquid crystal drive means 8, and displays an image according to the content of the image signal from the signal processing means 7.

This video display operation is the same as that of a known liquid crystal television or the like.

The light emitted from the light deflecting means 3 is transmitted to the liquid crystal display means 4 on which an image is displayed, and the image light according to the content of the image is transmitted from the liquid crystal display means 4 through the projection lens 5 and is enlarged and projected on the projection screen 6. It

FIG. 2 is a configuration perspective view showing the configuration of the condensing horizontal light diffusing unit 2.

In FIG. 2, the condensing horizontal light diffusing unit 2 is composed of a cylinder lens 21 having a condensing characteristic in only one direction, a linear optical fiber 22 and a light diffusing plate 23.

FIG. 3 is an operation explanatory view showing an operation of the converging horizontal light diffusing means 2.

In FIG. 3, the light emitted from the light source 1 is transmitted through the cylinder lens 21 to the linear end face 22a of the optical fiber 22.
Is focused on.

The light condensed on the line-shaped end face 22 a of the optical fiber 22 is guided to the light diffusing plate 23 by the optical fiber 22 and emitted to the light deflecting means 3.

More specifically, the light condensed by the cylinder lens 21 and incident on the end face of the optical fiber 22 has the brightest central portions e and f as shown in the lower section of FIG. a and j are the darkest.

The upper part of FIG. 4 shows a state in which the end face of the optical fiber 22 is divided into 10 parts by the alphabet a, ..., J (individual optical fiber) from the left side for convenience of explanation of the brightness distribution.

In order to eliminate the variation in brightness as shown in the lower part of FIG.
The positions of the individual optical fibers a to j of 22a and the end face 22b of the emission port were changed as shown in the upper part of FIG.

That is, while arranging the individual optical fibers e and f at the center and the individual optical fibers a and j on both sides next to each other,
As shown in the lower part of FIG. 5, they were arranged so that the average line L would be obtained by combining the adjacent ones.

The light emitted from the optical fiber 22 in which the individual optical fibers a to j are arranged in this way is incident on the diffuser plate 23.

Then, the light emitted from the diffuser plate 23 becomes uniform as if it has passed through the filter, and is emitted to the light deflecting means 3. The diffusing plate 23 can be omitted by using a fine optical fiber.

 FIG. 6 is a configuration diagram showing details of the light deflecting means 3.

In FIG. 6, the light deflecting means 3 is composed of an optical scanning polygon mirror 31, a motor 32 and a motor controller 33.

The light (a) incident from the condensing horizontal light diffusing means 2 is incident on the optical scanning polygon mirror 31, and the reflected light (b) is transmitted through the LCD panel and the projection lens 5, and is projected onto the projection screen 6 of the LCD panel. Magnify and project the image.

The optical scanning polygon mirror 31 scans the projection screen 6 once from top to bottom in one vertical period by the rotation of the connected motor 32.

The motor 32 is controlled by a motor controller 33 that performs control based on the input video synchronization signal.

FIG. 7 is an explanatory diagram showing a state of optical scanning on the projection screen 6.

 Optical scanning is performed in the direction of the arrow.

As described above, the liquid crystal projector according to the present invention condenses light emitted from the light source in the horizontal line direction,
By diffusing this, the brightness is made uniform, and the uniformed light can be transmitted through the LCD panel and a bright image can be enlarged and projected on the screen.

Further, it is possible to obtain a bright image by eliminating the diffuser plate by eliminating the diffuser plate by making the optical fiber of the converging horizontal diffuser means fine.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a liquid crystal projector according to the present invention, FIG. 2 is a configuration perspective view of a converging horizontal light diffusing unit, and FIG.
Fig. 4 is an explanatory diagram of its operation, Fig. 4 is an explanatory diagram showing the brightness distribution of the light condensed by the cylinder lens, and Fig. 5 is the arrangement state of the individual optical fibers at the end face of the optical fiber and the brightness distribution of the light. 6 is a configuration diagram showing the details of the light deflecting means, and FIG. 7 is an explanatory diagram of optical scanning of the projection screen. 1 ... Light source 2 ... Condensing horizontal light diffusing means 3 ... Light deflecting means 9 ... Synchronizing means

Claims (2)

(57) [Claims] 1. A liquid crystal projector for enlarging and projecting an image of an LCD panel on a screen by light from a light source, wherein the light from the light source is condensed on a horizontal line of the LCD panel to be uniformly scattered. Means, a synchronizing means for synchronizing the light emitted from the condensing horizontal light diffusing means with the input video signal, and a deflecting means for vertically deflecting the synchronized light to irradiate the LCD panel. LCD projector to do. 2. The condensing horizontal light diffusing means is characterized in that the light from the light source is incident on the linear end face of the optical fiber and the arrangement order of the emission ports is changed from the arrangement order of the incident light to make the emitted light uniform. The liquid crystal projector according to claim 1.