KR970006534Y1 - LCD Projector Using Liquid Crystal Panel - Google Patents

Abstract

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Description

LCD Projector Using Liquid Crystal Panel

1 to 4 are views for explaining a conventional LCD projector,

1 is a perspective view schematically showing the configuration of a conventional LCD projector.

2 is a block diagram of a conventional liquid crystal panel optical system.

3 is a plan view of FIG.

4 is a side view of FIG.

5 to 7 are views for explaining the LCD projector according to the present invention,

5 is a perspective view schematically showing the configuration of the LCD projector according to the present invention.

6 is a plan view of FIG.

7 is a side view of FIG.

Explanation of symbols on the main parts of the drawings

10: optical separation synthesis means 11: red mirror surface

12: Blue mirror surface 20, 20-1, 20-2, 20-3: R.G.B liquid crystal panel optical system

20a: liquid crystal panel 30, 30-1, 30-2, 30-3: R.G.B mirror optical system

40: lamp 50: projection lens

60: shielding plate 70, 70 ': polarizing filter

The present invention relates to an LCD (LCD) liquid crystal panel (LCD) projector using a liquid crystal panel (panel), in particular to reduce the use of the polarizing filter to increase the light efficiency and to separate the liquid crystal panel and the polarizing filter The present invention relates to an LCD projector using a liquid crystal panel that effectively solves a cooling problem and achieves a compact and highly efficient liquid crystal projector system.

Conventionally, a patent for a system of an LCD projector as shown in FIG. 1 has been proposed as a technique for constructing a compact system (Japanese Patent Laid-Open No. 63-144387).

This system attempts to overcome the difficulty of adjusting the optical parts and the bulky problem by using one optical separation synthesis means that simultaneously performs color separation / synthesis of red, green, and blue light emitted from a white light source. The operation process of is as follows.

First, the light emitted from the lamp is incident on the optical separation synthesizing means and separated into the RGB three primary colors by the color separation action of the optical separation synthesizing means, and then enters the RGB liquid crystal panel optical system through each mirror optical system, and then linearly The color-modulated light is again incident on the optical separation synthesizing means, synthesized by the color synthesizing action of the optical separation synthesizing means, and then projected onto the screen by the projection lens, thereby obtaining a large screen. On the other hand, the optical system as described above should polarize the light to drive the twisted nematic liquid crystal cell of the liquid crystal panel optical system, and uses a polarizing filter to polarize the light, as shown in Figure 2 liquid crystal panel optical system A total of six open filters are used before and after the liquid crystal panel. Due to this, the use efficiency of light is extremely low and, furthermore, the reduced light is deteriorated, making it difficult to cause cooling problems and deteriorating performance as well as prolonged use.

Therefore, the present invention aims to provide a compact and highly efficient liquid crystal projector system by reducing the use of the polarizing filter to increase the light efficiency and effectively solve the cooling problem by separating and arranging the liquid crystal panel and the polarizing filters.

1 to 3 are cross-sectional views showing the configuration of a conventional LCD projector, as shown therein, optical separation and synthesizing means 10 for simultaneously performing color separation / synthesis of red, green and blue light, and the optical separation and synthesizing means thereof. RGB liquid crystal panel optical systems 20-1, 20-2 and 20-3 disposed on three surfaces of (10) to modulate the separated colors, and RGB liquid crystal panel optical systems for injecting light into the liquid crystal panel optical system. 30-1, 30-2, 30-3, a lamp 40 for emitting light, a projection lens 50 for imaging modulated light on a screen (not shown), and the projection lens ( 50) and a shielding plate 60 for blocking the lamp 40.

In addition, the optical separation synthesis means 10 may use a dichroic mirror or a dichroic prism, and the dichroic mirror or dichroic prism reflects red light, and a red mirror transmitting green and blue light. The surface 11 is composed of a blue mirror surface 12 that reflects blue light and transmits red and green light, and the two mirrors 11 and 12 cross each other at 90 °.

The RGB liquid crystal panel optical system 20-1, 20-2, and 20-3 includes a liquid crystal panel 20a for modulating incident light as shown in FIG. 2, and the liquid crystal panel 20a of the liquid crystal panel 20a. It consists of two polarizing filters 20b and 20c which are arranged before and after and polarize light. A total of six such polarizing filters are used in a conventional apparatus.

In the conventional LCD projector configured as described above, as shown in FIG. 4, the light emitted from the lamp 40 is incident to the optical separation synthesizing means 10 and separated into three primary colors of RGB, respectively, to the mirror optical system 30. When the light separation process is performed, first, red (R) light is reflected on the red mirror surface 11 of the optical separation synthesis means 10 and is incident on the red mirror optical system 30-1, and blue (b) The light is reflected by the blue mirror surface 12 and is incident on the blue mirror optical system 30-3, and the green (G) light passes through both the red mirror surface 11 and the blue mirror surface 12 and the green mirror optical system 30 It is incident to -2) and color separation is performed.

Meanwhile, light incident on each of the mirror optical systems 30-1, 30-2, and 30-3 is incident on each of the RG B liquid crystal panel optical systems 20-1, 20-2, and 20-3. After being modulated, it is synthesized while passing through the optical separation and synthesizing means 10 in the above-described path, and imaged on a screen (not shown) by the projection lens 50 to obtain an enlarged image.

As described above, the light of the RG B three primary colors separated by the optical separation synthesizing means 10 is RG B liquid crystal panel optical system by the respective mirror optical systems 30-1, 30-2 and 30-3. 20-1) (20-2) (20-3) is incident on a conventional LCD projector, which uses a polarizing filter that polarizes light to drive a twisted nematic liquid crystal cell. Conventional LCD projectors before and after the liquid crystal panel (20a) of the RG B liquid crystal panel optical system (20-1) (20-2) (20-3) to the polarization filter (20b, 20c) to obtain this polarized light Arranged to get polarized light, total 6 polarization filters are used.

In general, the light is reduced by about 50% by passing through one polarization filter. Since the conventional LCD projector uses a total of six polarization filters, the loss of light is large, and the lost light is thermally deteriorated. The cooling problem is difficult, and this causes a performance deterioration and a defect that causes a great problem for long time use.

Therefore, the present invention improves the efficiency of use of light by reducing the use of the polarization filter in order to solve the above-mentioned defects as described above, and effectively solves the cooling problem by separating the polarization filter from the liquid crystal panel. When described in detail by the accompanying drawings as follows.

5 and 6 are cross-sectional views showing the configuration of the LCD projector according to the present invention, and the optical separation and synthesizing means 10 for simultaneously performing color separation / synthesis of red, green, and blue light, as shown in FIG. Light is incident on the RGB liquid crystal panel optical system 20-1, 20-2, 20-3 which modulates color, and the respective liquid crystal panel optical systems 20-1, 20-2, 20-3. In the optical system comprising an RGB mirror optical system 30-1, 30-2, 30-3, a lamp 40 for emitting light, and a projection lens 50 for imaging modulated light on a screen. In addition, the polarization filter 70 for polarizing light between the lamp 40 and the optical separation synthesis means 10 is disposed perpendicular to the optical axis, and the other polarization filter 70 'is formed by the optical separation synthesis means ( 10) between the projection lens 50 and the use of two polarization filters 70, 70 '.

In the LCD projector of the present invention configured as described above, as shown in FIG. 7, the light emitted from the lamp 40 is formed by the polarization filter 70 disposed between the lamp 40 and the optical separation and synthesizing means 10. Linearly polarized light is incident on the optical separation and synthesis means 10. Of these incident lights, red light is reflected on the red mirror surface 11 of the optical separation synthesis means 10 and is incident on the red mirror optical system 30-1, and blue light is reflected on the blue mirror surface 12 to reflect the blue mirror. Incidentally, the green light is incident on the optical system 30-3 and passes through the red mirror surface 11 and the blue mirror surface 12 to enter the green mirror optical system 30-2. Light incident on each of the mirror optical systems 30-1, 30-2, and 30-3 is reflected to enter the respective liquid crystal panel optical systems 20-1, 20-2, and 20-3. The modulated and modulated light is incident on the optical separation synthesizing means 10 by the above-described path, synthesized, and then polarized light 70 'disposed between the optical separation synthesizing means 10 and the projection lens 50. ) Is projected on the screen (not shown) by the projection lens 50.

In the drawings, the same parts as in the conventional construction are denoted by the same reference numerals.

As described above, the LCD projector according to the present invention maximizes the use efficiency of light by reducing the use of the polarizing filter that polarizes the light to two, thereby improving the performance, and the position of the polarizing filter is also determined by the liquid crystal panel. The cooling problem can be efficiently solved by installing it separately from the device. Therefore, a compact and highly efficient liquid crystal projector system can be realized.

Claims (1)

(Separation) an optical separation synthesis means (10) for simultaneously performing color separation / synthesis of red, green, and blue light, and an RG B liquid crystal panel optical system (20-1) (20-2) (20) for modulating the separated color signal 3 and RG B mirror optical systems 30-1, 30-2 and 30-3 for injecting light into the respective liquid crystal panel optical systems 20-1, 20-2 and 20-3. And a lamp 40 for emitting light, a projection lens 50 for imaging modulated light on the screen, and a light separation from the lamp 40, the optical separation synthesis means 10, and the projection lens 50. An LCD projector using a liquid crystal panel for the purpose of configuring a polarizing filter (70, 70 ') arranged to be perpendicular to the optical axis between the synthesizing means (10) to polarize light.