Projection type liquid crystal displaying device

• US 4,861,142 A
• Filed: 05/12/1987
• Issued: 08/29/1989
• Est. Priority Date: 05/12/1986
• Status: Expired due to Term

• Current Assignee: Seiko Precision Incorporated (Seiko Group Corp.)
• Original Assignee: Seikosha Co., Ltd.
• Inventors: Takahashi, Shingo, Takahashi, Tomoaki, Tanaka, Sakae, Yamaoka, Tadahiko
• Primary Examiner(s): Miller, Stanley D.
• Assistant Examiner(s): Mai, Huy Kim
• Application Number:
  US07/049,718
• Time in Patent Office: 840 Days
• Field of Search: 350/338, 350/345, 350/337, 350/342, 350/408, 353/34, 353/37
• US Class Current: 349/8
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

Light emitted from a single light source is split into beams of bidirectional parallel light which are orthogonal to each other. Beams of the parallel light in each direction are reflected by a reflection optical system in such a direction that they become orthogonal to each other. A dichroic mirror is disposed at a point of intersection thereof and liquid crystal panels are provided between each individual reflection optical system and the dichroic mirror resulting in a low cost device which can be structurally miniaturized and which requires less process steps in fabrication.

Claims

1. A projection type liquid crystal displaying device comprising:

a light source;

condenser lenses for splitting light emitted from said light source into two orthogonal groups of beams of substantially parallel light;

two optical reflection means, each in the path of one of the beams of light, for effecting the beams of the light of the two groups to reflect at a right angle to an area in which the beams of light of the two groups cross each other;

a dichroic mirror disposed in said area for synthesizing beams of the light from the two optical reflection means including means for transmitting the light coming from one of said optical reflection means and for reflecting the light from the other of said optical reflection means;

a liquid crystal panel comprising green picture elements disposed between said dichroic mirror and one of said optical reflection means;

a liquid crystal panel comprising red and blue picture elements disposed between said dichroic mirror and the other of said optical reflection optical means; and

projection means for projecting beams of the light from said dichroic mirror.

2. A projection type liquid crystal displaying device comprising:

a light source;

first condenser lenses for splitting the light emitted from said light source into two orthogonal groups of beams of substantially parallel light;

two optical reflection means, each in the path of one of the beams of light, for effecting the beams of light of the two groups to reflect at a right angle to an area in which the beams of the light of the two groups cross each other;

a dichroic mirror disposed in said area for synthesizing beams of light from said optical reflection means including means for transmitting the light coming from one of said optical reflection means and for reflecting the light from the other of said optical reflection means;

a liquid crystal panel comprising green picture elements disposed between said dichroic mirror and one of said optical reflection means;

a liquid crystal panel comprising red and blue picture elements disposed between said dichroic mirror and the other of said optical reflection means;

second condenser lenses for converging the light transmitted through each of said liquid crystal panels at a given angle; and

projection means for projecting beams of the light from said dichroic mirror.

3. The projection type liquid crystal displaying device as set forth in claim 2, wherein the given angle ranges from 0°

to 5°

.