Projection type color liquid crystal optical apparatus

• US 5,754,260 A
• Filed: 02/27/1997
• Issued: 05/19/1998
• Est. Priority Date: 10/09/1992
• Status: Expired due to Term

• Current Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Original Assignee: AG Technology Co., Ltd.
• Inventors: Ooi, Yoshiharu, Serizawa, Shigeyuki, Wakabayashi, Tsuneo, Sonda, Yoshiyuki, Hirai, Yoshinori, Kunigita, Masaya
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Duong, Tai V.
• Application Number:
  US08/810,984
• Time in Patent Office: 446 Days
• Field of Search: 349/5, 349/7, 349/8, 349/10, 349/61, 349/62, 349/67, 349/86, 349/114, 349/139, 349/143, 349/201, 353/31, 353/34, 353/33, 353/37, 353/102, 353/122, 348/751, 348/756, 348/757, 348/742
• US Class Current: 349/10
• 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
• CPC Class Codes: H04N 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20

Abstract

A light source optical system for projection 1, dichroic mirrors 21, 22 disposed to have a predetermined included angle β, a reflection type liquid crystal optical element blocks 31-33 each including a closely contacted converging lens and having a reflection surface and a projection optical system 4 are provided, wherein the normal line of a dichroic mirror surface and the optical axis of incident light form an included angle α; the normal line of the reflection surface and the optical axis of incident light form an included angle γ; light emitted from a light source is color-separated so as to become color lights; the color lights are rendered to be parallel light beams, and are modulated and reflected by means of the reflection type liquid crystal optical elements; the reflected light beams are color-synthesized; and the color-synthesized light is projected through a projection lens. A projection type color liquid crystal optical apparatus having a compact shape and a high brightness is obtainable.

Claims

1. A projection type liquid crystal optical apparatus comprising:

(a) a light source system comprising a light source that emits a light, a reflection mirror and a first aperture device;

(b) a light modulation system configured to modulate a light which is emitted from an opening of said first aperture device, comprising,

(b₁) a liquid crystal optical element having a front substrate with a transparent front electrode wherein minute concaves and convexes are formed on a surface of the front electrode or on an interface of the front substrate, a back substrate with reflective pixel electrodes, a liquid crystal and solidified matrix composite layer disposed between said front substrate and said back substrate, and

(b₂) condenser lens having a convex surface and a plane surface facing said liquid crystal optical element; and

(c) a light projection optical system comprising projection lenses and a second aperture device having an aperture, wherein a modulated light in said light modulation system is passed through the aperture of said second aperture device.

2. A projection type liquid crystal optical apparatus according to claim 1, further comprising a color separating and synthesizing system comprising two color separating and synthesizing layers being arranged in a horizontal plane with an included angle of 40°

to 70°

with respect to each other;

wherein

said light emitted from said light source system having an incident angle of a₁, a₂ in a range of 20°

to 35°

with respect to each of said color separating and synthesizing layers, and

three liquid crystal optical elements in said light modulation system being arranged for three color lights respectively separated by said color separating and synthesizing layers.

3. A projection type liquid crystal optical apparatus according to claim 1, wherein said first aperture device is configured to have a changeable aperture opening size and said second aperture device is configured to have a changeable aperture opening size.

4. A projection type liquid crystal optical apparatus according to claim 2, wherein said first aperture device is configured to have a changeable aperture opening size and said second aperture device is configured to have a changeable aperture opening size.

5. A projection type liquid crystal optical apparatus according to claim 1, wherein said condenser lens having a convex front surface and a plane back surface is attached to a front surface of said liquid crystal optical element.

6. A projection type liquid crystal optical apparatus according to claim 2, said condenser lens having a convex from surface and a plane back surface is attached to a front surface of said liquid crystal optical element.

7. A projection type liquid crystal optical apparatus according to claim 3, said condenser lens having a convex front surface and a plane back surface is attached to a front surface of said liquid crystal optical element.

8. A projection type liquid crystal optical apparatus according to claim 4, said condenser lens having a convex front surface and a plane back surface is attached to a front surface of said liquid crystal optical element.

9. A projection type liquid crystal optical apparatus according to claim 1, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

10. A projection type liquid crystal optical apparatus according to claim 2, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

11. A projection type liquid crystal optical apparatus according to claim 3, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

12. A projection type liquid crystal optical apparatus according to claim 4, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

13. A projection type liquid crystal optical apparatus according to claim 5, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

14. A projection type liquid crystal optical apparatus according to claim 6, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

15. A projection type liquid crystal optical apparatus according to claim 7, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

16. A projection type liquid crystal optical apparatus according to claim 8, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

17. A projection type liquid crystal optical apparatus according to claim 9, wherein said light emitted from said light source system has a collection angle less than or equal to 10°

.

18. A projection type liquid crystal optical apparatus according to claim 2, wherein said color separating and synthesizing layers comprise a dichroic mirror.

19. A projection type liquid crystal optical apparatus according to claim 1, wherein an opening shape of said aperture of said first aperture device is similar to an opening shape of said aperture of said second aperture device.

20. A projection type liquid crystal optical apparatus according to claim 2, wherein an opening shape of said aperture of said first aperture device is similar to an opening shape of said aperture of said second aperture device.