Reflective-type liquid crystal projection system

• US 6,652,103 B2
• Filed: 12/10/2001
• Issued: 11/25/2003
• Est. Priority Date: 12/10/2001
• Status: Active Grant

• Current Assignee: CPT Technology (Group) Co., Ltd.
• Original Assignee: Chunghwa Picture Tubes Limited
• Inventors: Chiang, Yai-Hui
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US10/006,230
• Publication Number:
  US 20030107710A1
• Time in Patent Office: 715 Days
• Field of Search: 353/20, 353/31, 353/33, 353/34, 353/37, 353/38, 353/84, 349/5, 349/8, 349/9
• US Class Current: 353/31
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10

Abstract

A reflective-type liquid crystal projection system consists of a dichroic prism that diffracts the light beam generated by a light source module into two colored light beams of different wavelengths; and three polarizing light flux splitter prisms that are symmetrically disposed around the said dichroic prism as well as two related converging lens groups enabling three RGB color images shown on three reflective-type liquid crystal display panels to be merged into a single image and then projected onto a television screen for viewing.

Claims

1. A reflective-type liquid crystal projection system with a single dichroic mirror, comprising:

a light source generating a beam of light;

a mirror for reflecting said beam of light from said light source;

a dichroic mirror for receiving said beam of light from said mirror and splitting said beam into two beams of colored light, wherein a first beam of colored light is reflected and a second beam of colored light is transmitted;

a first polarizing light flux splitter prism for receiving said first beam of colored light;

a color selector filtering lens between said dichroic mirror and said first polarizing light flux splitter prism;

a first reflective-type liquid crystal display panel for receiving said first beam of colored light from said first polarizing light flux splitter prism to form a first image and reflect said first image back to said first polarizing light flux splitter prism;

a second polarizing light flux splitter prism for receiving said second beam of colored light and for splitting the second beam into a third beam of colored light and a fourth beam of colored light;

a second reflective-type liquid crystal display panel for receiving said third beam of colored light from said second polarizing light flux splitter prism to form a second image and reflect said second image back to said second polarizing light flux splitter prism;

a third reflective-type liquid crystal display panel for receiving said fourth beam of colored light from said second polarizing light flux splitter prism to form a third image and reflect the third image back to said second polarizing light flux splitter prism;

a third polarizing light flux splitter prism for receiving said first image, said second image, and said third image to merge a single image from said first polarizing light flux splitter prism and said second polarizing light flux splitter prism; and

a lens module receiving said single image for viewing.

2. The reflective-type liquid crystal projection system according to claim 1, wherein said mirror redirects said beam of light from said light source by 90 degrees.

3. The reflective-type liquid crystal projection system according to claim 2, further comprising a filter lens group between said light source and said mirror.

4. The reflective-type liquid crystal projection system according to claim 3, further comprising a first convergent lens between said filter lens group and said dichroic mirror.

5. The reflective-type liquid crystal projection system according to claim 4, further comprising a color selector filtering lens between said dichroic mirror and said first polarizing light flux splitter prism.

6. The reflective-type liquid crystal projection system according to claim 1, further comprising a first retarder between said first polarizing light flux splitter prism and said third polarizing light flux splitter prism, and a second retarder between said first polarizing light flux splitter prism and said dichroic mirror.

7. The reflective-type liquid crystal projection system according to claim 4, further comprising a color selector filtering lens between said dichroic mirror and said second polarizing light flux splitter prism.

8. The reflective-type liquid crystal projection system according to claim 4, further comprising a color selector lens between said second polarizing light flux splitter prism and said third polarizing light flux splitter prism.