Projector

• US 8,619,202 B2
• Filed: 12/15/2011
• Issued: 12/31/2013
• Est. Priority Date: 01/14/2011
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Haruyama, Akihide
• Primary Examiner(s): Glick, Edward
• Assistant Examiner(s): Nguyen, Sang V
• Application Number:
  US13/326,594
• Publication Number:
  US 20120182486A1
• Time in Patent Office: 747 Days
• Field of Search: 349/107, 349/5, 349/109, 349/78, 349/81, 349/83, 349/84, 349/7, 349/86
• US Class Current: 349/5
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• 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 9/317 Convergence or focusing systems electronic adjustment of convergence H04N9/3185; convergence or focusing arrangements for cathode ray tubes H04N9/28; means for automatic focusing of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/53

Abstract

A projector includes: a lighting device that emits light of a plurality of different colors; a plurality of liquid crystal light valves that modulate the light of a plurality of colors; a color synthesizing optical system that synthesizes the color light modulated by the plurality of liquid crystal light valves; and a projection optical system that projects the light synthesized by the color synthesizing optical system to a projection target face. A cell thickness of one liquid crystal light valve modulating light of one color of the plurality of liquid crystal light valves is smaller than a cell thickness of the other liquid crystal light valves modulating the light of other colors, and an alignment state of liquid crystal at the time of applying the maximum gradation voltage is substantially the same in one liquid crystal light value and the other liquid crystal light valve.

Claims

1. A projector comprising:

a lighting device that emits light that includes a first color and a second color;

a first liquid crystal light valve that modulates the first color;

a second liquid crystal light valve that modulates the second color; and

a color synthesizing optical system that superimposes the first color and the second color modulated by the first liquid crystal light valve and the second liquid crystal light valve, respectively,

wherein a cell thickness of the first liquid crystal light valve is smaller than a cell thickness of the second liquid crystal light valve, and an alignment state of liquid crystal at the time of applying a maximum gradation voltage is substantially the same in the first liquid crystal light valve and the second liquid crystal light valve.

4. The projector according to claim 1,

wherein the first liquid crystal light valve has a first insulating film that is formed between a liquid crystal layer of the first liquid crystal light valve and a pixel electrode of the first liquid crystal light valve,

the second liquid crystal light valve has a second insulating film that is formed between a liquid crystal layer of the second liquid crystal light valve and a pixel electrode of the second liquid crystal light valve, and

a film thickness of the first insulating film is smaller than a film thickness of the second insulating film.

6. The projector according to claim 1, wherein the first color is a blue color and the second color is a green color.

7. The projector according to claim 1, wherein the liquid crystal light valve is a reflex-type liquid crystal light valve.

9. The projector according to claim 1,

wherein the first liquid crystal light valve has a first insulating film that is formed between a liquid crystal layer of the first liquid crystal light valve and a common electrode of the first liquid crystal light valve,

the second liquid crystal light valve has a second insulating film that is formed between a liquid crystal layer of the second liquid crystal light valve and a common electrode of the second liquid crystal light valve, and

a film thickness of the first insulating film is smaller than a film thickness of the second insulating film.

2. A projector comprising:

a lighting device that emits light that includes a first color and a second color;

a first liquid crystal light valve that modulates the first color;

a second liquid crystal light valve that modulates the second color; and

a color synthesizing optical system that superimposes the first color and the second color modulated by the first liquid crystal light valve and the second liquid crystal light valve, respectively,

wherein refractive index anisotropy of liquid crystal of the first liquid crystal light valve is smaller than refractive index anisotropy of liquid crystal of the second liquid crystal light valve, and an alignment state of liquid crystal at the time of applying a maximum gradation voltage is substantially the same in the first liquid crystal light valve and the second liquid crystal light valve, and

a liquid crystal material of the first liquid crystal light valve is different than a liquid crystal material of the second liquid crystal light valve.

8. The projector according to claim 2, wherein the first color is a blue color and the second color is a green color.

3. A projector comprising:

a lighting device that emits that includes a first color and a second color;

a first liquid crystal light valve that modulates the first color;

a second liquid crystal light valve that modulates the second color; and

a color synthesizing optical system that superimposes the first color and the second color modulated by the first liquid crystal light valve and the second liquid crystal light valve, respectively,

wherein a pre-tilt angle of liquid crystal molecules of the first liquid crystal light valve is smaller than a pre-tilt angle of liquid crystal molecules of the second liquid crystal light valve, and an alignment state of liquid crystal at the time of applying a maximum gradation voltage is substantially the same in the first liquid crystal light valve and the second liquid crystal light valve.

5. A projector comprising:

a lighting device that emits light that includes a first color and a second color;

a first liquid crystal light valve that modulates the first color;

a second liquid crystal light valve that modulates the second color; and

a color synthesizing optical system that superimposes the first color and the second color modulated by the first liquid crystal light valve and the second liquid crystal light valve, respectively,

wherein the first liquid crystal light valve has a first insulating film that is formed between a liquid crystal layer of the first liquid crystal light valve and a pixel electrode of the first liquid crystal light valve,

the second liquid crystal light valve has a second insulating film that is formed between a liquid crystal layer of the second liquid crystal light valve and a pixel electrode of the second liquid crystal light valve,

a film thickness of the first insulating film is smaller than a film thickness of the second insulating film, and

an alignment state of liquid crystal at the time of applying a maximum gradation voltage is substantially the same in the first liquid crystal light valve and the second liquid crystal light valve.