JPH0452634A - Liquid crystal video projector - Google Patents

Abstract

PURPOSE:To offer this projector which can vary the screen size freely after convergence composition by providing a dichroic mirror which is so arranged that optically modulated light is color-mixed and made incident on a projection lens with variable focal length. CONSTITUTION:Light which is emitted by a lamp 7 and color-separated by a 1st dichroic mirror 8-a is made incident on polarization beam splitters 5 of blue, green, and red and separated into vertical and horizontal components. The parallel components are reflected toward a 1st liquid crystal panel 1 to enter liquid crystal cells cell 3, where the polarizing direction is rotated as the light is propagated; and the light is made incident on total reflecting mirrors 4 and reflected totally. The totally reflected light components are transmitted through the liquid crystal cells and made incident on and transmitted through splitters 5. The vertical components, on the other hand, are transmitted through the splitters 5 and made incident on 2nd liquid crystal panels 2, where the same operation as above-mentioned is performed, so that the components are made incident on and reflected by the splitters 5. The light components which are optically modulated and exit from the splitters 5 are color-mixed by the 2nd dichroic mirror 8-b which is so arranged that the light is made incident on the projection lens 6 with variable focal length, so that the composite light is projected by the projection lens.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid crystal video projector used as an image display device or the like.

2. Description of the Related Art In recent years, display devices using liquid crystals have made remarkable progress, and in particular, liquid crystal video projectors that enlarge and display images are becoming popular.

Hereinafter, a conventional liquid crystal video projector as described above will be explained with reference to the drawings.

FIGS. 3 and 4 show the structure of a conventional liquid crystal video projector.

1 in FIG. 3 is a first liquid crystal panel that displays images. 2 is a second liquid crystal panel. Reference numeral 3 denotes a liquid crystal cell constituting the first liquid crystal panel 1 and the second liquid crystal panel 2. 4
is a total reflection mirror that constitutes the first liquid crystal panel 1 and the second liquid crystal panel 2 together with the liquid crystal cell 3. 5 is a polarizing beam splitter that separates natural light into vertical and parallel components. 6 is a projection lens, 7 is a lamp, and 8 shown in FIG. 4 is a dichroic mirror that separates natural light into colors.

The operation of the liquid crystal video projector constructed as described above will be explained below with reference to FIGS. 3 and 4.

In the third session, polarizing beam splitter 5 was used from lamp 7.
The incident natural light is separated into a parallel component and a perpendicular component by the polarizing beam splitter 5. The separated parallel components are reflected toward the first liquid crystal panel 1 and are reflected to the liquid crystal cell 3.
incident on . Due to the optical rotation of the liquid crystal cell 3, the polarization direction of the incident parallel component rotates as the light propagates, and the incident light component enters the total reflection mirror 4 as a light component with a 45° phase shift from the incident light component, where it is totally reflected. . The totally reflected light component passes through the liquid crystal cell 3, enters the polarizing beam splitter 5 as a component with a phase shift of 90 degrees from the parallel component separated by the polarizing beam splitter 5, and is projected by the projection lens 6. be done.

On the other hand, the vertical component separated by the polarizing beam splitter 5 passes through the polarizing beam splitter 5, and the vertical component is separated by the polarizing beam splitter 5.
The light enters the liquid crystal display lens 2. A light component incident on the liquid crystal panel 2 by the second liquid crystal panel 2 having the same function as the first liquid crystal panel 1 is reflected as a light component with a phase shift of 90°, and enters the polarizing beam splitter 5. The light component reflected by the polarizing beam splitter 5 is projected by a projection lens 6.

In FIG. 4, a dichroic mirror 8 for color-separating natural light is placed between the lamp 7 and the polarizing beam splitter 5 configured as shown in FIG. The light is incident on the printer 5, reflected by the first liquid crystal panel 1 and the second liquid crystal panel 2, and is enlarged and projected onto a screen (not shown) by the projection lens 6.

Problems that the invention aims to solve However, in the above configuration, natural light is blue.

The problem is that the screen size cannot be changed because the colors are separated into green and red, each is enlarged and projected onto a screen, and each color is convergently synthesized on the screen.

The present invention provides a liquid crystal video projector in which the screen size can be freely changed after convergence synthesis and stereoscopic viewing can be performed.

Means for Solving the Problems In order to solve the above problems, the liquid crystal video projector of the present invention includes a first dichroic mirror that separates incident light into colors, and at least one reflective liquid crystal panel that optically modulates a video signal. a polarizing beam splitter that separates the incident light into a vertical component and a parallel component, and a second dichroic that is arranged so as to combine the colors of the modulated light and make it enter a projection lens whose focal length can be varied. It is characterized by being equipped with a mirror.

Function The above configuration separates natural light into blue, green, and red.
After enlarging and projecting each color onto the screen and converging the image information of each color on the screen, the screen size can be freely changed and the reflective liquid crystal included in the polarizing beam splitter can be adjusted to match the spectral distribution of the lamp. By providing one or two panels for blue, green, and red, the brightness ratio of blue, green, and red on the screen can be adjusted. Furthermore, by providing two reflective liquid crystal panels in the polarizing beam splitter, different image information can be input into the vertical and parallel components of the projected light, making stereoscopic viewing variable.

Embodiment A liquid crystal video projector according to an embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show the structure of a liquid crystal video projector according to an embodiment of the present invention.

In FIGS. 1 and 2, reference numeral 1 denotes a first liquid crystal panel that displays images. 2 is a second liquid crystal panel.

3 is the first liquid crystal panel 1. This is a liquid crystal cell that constitutes the second liquid crystal panel 2. 4 includes a first liquid crystal panel 1 along with a liquid crystal cell 3. This is a total reflection mirror that constitutes the second liquid crystal panel 2. 5 is a polarizing beam splitter that separates natural light into a vertical component and a parallel component.

6 is a projection lens whose focal length can be varied. 7 is a lamp. 8-a is a first dichroic mirror that separates natural light into colors. 8-b is a second lens arranged to color-combine the modulated light and make it enter the projection lens 6;
It's a Guikreutsch mirror. Reference numeral 9 denotes a cold mirror that transmits the infrared light component of the light component emitted from the lamp 7 and reflects the other light components. In FIG. 1, the central polarizing beam splitter 5 has two polarizing beam splitters perpendicular to each other.
LCD panel 1. A second liquid crystal panel 2 is arranged,
The other two polarizing beam splitters 5 have one liquid crystal panel 2 disposed on only one surface.

On the other hand, in FIG. 2, liquid crystal panels 1.2 are arranged on two sides of each of three polarizing beam splitters 5.

The operation of the liquid crystal video projector constructed as described above will be explained below with reference to FIGS. 1 and 2. In FIGS. 1 and 2, the light emitted from the lamp 7 is reflected by the cold mirror 9 except for the infrared light component, and is directed toward the first dichroic mirror 8-a. The light separated by color by the first dichroic mirror 8-a enters the polarizing beam splitter 5, respectively, for blue and green light. Natural light incident on the polarizing beam splitter 5 is separated into a vertical component and a parallel component. The separated parallel component is reflected toward the first liquid crystal panel 1 and enters the liquid crystal cell 3. Due to the optical rotation of the liquid crystal cell 3, the polarization direction of the incident parallel component rotates according to the propagation of the light, and the polarization direction of the incident parallel component rotates with the incident light component.
The light enters the total reflection mirror 4 as a light component with a phase shift of 5°, and is totally reflected. The totally reflected light component passes through the liquid crystal cell 3, and enters and passes through the polarizing beam splitter 5 as a light component whose phase is shifted by 90 degrees from the parallel component separated by the polarizing beam splitter 5.

On the other hand, the vertical component separated by the polarizing beam splitter 5 passes through the polarizing beam splitter 5, and the vertical component is separated by the polarizing beam splitter 5.
The light enters the liquid crystal panel 2. The light component incident on the second liquid crystal panel 2 is reflected by the second liquid crystal panel 2 having the same function as the first liquid crystal panel 1 as a light component with a phase shift of 90°, and is incident on the polarizing beam splitter 5. , reflected.

However, each of the blue, green, and red reflective liquid crystal panels may include only the first liquid crystal panel 1, only the second liquid crystal panel 2, or both. Light modulated and polarized beam splitter-5
The emitted light component is transmitted through a projection lens 6 whose focal length can be changed.
The colors are synthesized by the second dichroic mirror 8-b arranged so as to make the light incident on the light beam, and the light is projected by the projection lens 6. In Fig. 1, the same video information is entered in both the first and second liquid crystal panels, and in Fig. 2, the first and second liquid crystal panels contain the same image information.
Different video information is input into the liquid crystal panel and the second liquid crystal panel. Therefore, in FIG. 2, stereoscopic vision can be obtained.

As described above, according to this embodiment, after the video information of each color of blue, green, and red is converged and synthesized on the screen, the screen size can be freely changed, and the screen size can be adjusted according to the spectral distribution of the lamp 7. Effects of the Invention As described above, according to the present invention, a dichroic mirror for color-separating incident light and at least one for optically modulating a video signal are provided.
It is equipped with a polarizing beam splitter that is equipped with two reflective liquid crystal panels and separates the incident light into vertical and parallel components, and combines the colors of the modulated light and makes it enter a projection lens that can change the focal length. Equipped with a Gwikro ink mirror, the screen size can be freely changed after the video information of each color of blue, green, and red is converged and synthesized on the screen, and the screen size can be adjusted according to the spectral distribution of the lamp. The brightness ratio of blue, green, and red can be adjusted, and a liquid crystal video projector that can provide stereoscopic viewing can be obtained.

[Brief explanation of drawings]

FIGS. 1 and 2 are block diagrams of a liquid crystal video projector according to an embodiment of the present invention, FIG. 3 is a block diagram of a conventional liquid crystal video projector, and FIG. 4 is a color separation of the configuration shown in FIG. 3. 1 is a perspective view of the structure of a liquid crystal video projector equipped with an A function. 1... First liquid crystal panel, 2... Second liquid crystal panel, 3
... Liquid crystal cell, 4... Total reflection mirror, 5 Polarizing beam splitter - 16... Projection lens, 7... Lamp,
8-a...first dichroic mirror, 8-b...
Name of the 2nd Guikreutzkmirr agent: Patent attorney Shigetaka Awano Haka 1/-IA
f 511j: eBawinter 2, custom? LCD panel 3 Projects the LCD panel 1st LCD screen? Fittings panel 6 Dim body: i Shins 7 -7 Ship-OL Kuzu 1 Kushibafuru

Claims (2)

[Claims] (1) A polarizing beam splitter that includes a first dichroic mirror that separates incident light into colors and at least one reflective liquid crystal panel that optically modulates a video signal, and that separates incident light into a vertical component and a parallel component; A liquid crystal video projector comprising a second dichroic mirror disposed so as to color-combine the modulated light and make it enter a projection lens whose focal length can be varied. (2) A first dichroic mirror that separates the incident light into colors, first and second reflective liquid crystal panels that optically modulate the video signal, and a first dichroic mirror that separates the incident light into a vertical component and a parallel component. A polarizing beam splitter that makes the vertical component enter the first reflective liquid crystal panel and a second reflective liquid crystal panel, and a polarizing beam splitter that combines the colors of the light modulated light and makes it enter a projection lens whose focal length can be varied. The second placed
LCD video projector with dichroic mirror.