Projection display device

• US 6,056,407 A
• Filed: 08/12/1998
• Issued: 05/02/2000
• Est. Priority Date: 12/18/1996
• Status: Expired

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Fujimori, Motoyuki, Kitabayashi, Masashi, Iinuma, Kazuyuki, Shinohara, Kazuto
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US09/117,857
• Time in Patent Office: 629 Days
• Field of Search: 353/31, 353/33, 353/34, 353/81, 353/119, 353/120, 353/122, 349/58, 349/60
• US Class Current: 353/119
• CPC Class Codes: G02B 27/1046 for use with transmissive spatial light modulators
• CPC Class Codes: G02B 27/1073 characterized by manufacturing or alignment methods
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G03B 21/006 using LCD's
• CPC Class Codes: G03B 21/145 Housing details, e.g. position adjustments thereof
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• 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
• 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 liquid crystal panel unit is provided on the light incident face of a prism combining body. The unit has a light valve frame plate for holding a liquid crystal panel and a fixing frame plate fixed onto the light incident face with an adhesive layer. The light valve frame plate is screwed onto the fixing frame plate with a medial frame therebetween. By using wedge members, by adjusting the position of the light valve frame plate on the light incident face, it is possible to precisely position and fix the liquid crystal panel which is held there so that it is possible to control the shifted amount of the pixel alignment and precisely adjust the focus. Thus, it is possible to easily improve the accuracy. Furthermore, the fixing frame plate and the light valve frame plate are composed of materials having linear expansion coefficients ranging from 1/4 to four times that of the prism combining body and from 1/5 to five times that of the fixing frame plate, respectively.

Claims

1. A projection display device, that includes a plurality of light valves that modulate a plurality of color lights in response to image information, and an optical combining device including a prism body that combines the modulated color lights, a projection system that enlarges and projects an image, said projection display device comprising:

a fixing frame plate fixed onto a light incident face of said prism body, a light valve frame plate that holds said light valve, a fixing member that fixes the light valve frame plate onto said fixing frame plate, and a positioning member that fixes said light valve relative to the light incident face of said prism body;

said fixing frame plate comprising a material having a linear expansion coefficient ranging from one quarter to four times a linear expansion coefficient of said prism body; and

said light valve frame plate comprising a material having a linear expansion coefficient ranging from one-fifth to five times a linear expansion coefficient of said fixing frame plate.

2. The projection display device of claim 1,

linear expansion coefficients E1, E2, and E3, of said prism body, said fixing frame plate, and said light valve frame plate, respectively, satisfying the relationship E1<

E2<

E3.

3. The projection display device of claim 1,

said fixing frame plate comprising a material having a linear expansion coefficient ranging from one half to two times the linear expansion coefficient of said prism body.

4. The projection display device of claim 1,

said light valve frame plate comprising a material having a linear expansion coefficient ranging from one half to two times a linear expansion coefficient of said fixing frame plate.

5. The projection display device of claim 1,

said fixing frame plate comprising a metal or a composite material comprising a metal.

6. The projection display device of claim 1,

said light valve frame plate comprising a resin or a composite material comprising a resin.

7. The projection display device of claim 1,

said projection display device further comprising a medial frame plate provided between said fixing frame plate and said light valve frame plate, said medial frame plate being fixed to said fixing frame plate by said fixing member and being bonded to said light valve frame plate after being positioned by said positioning member.

8. The projection display device of claim 7,

further comprising, a temporary fixing member between said medial frame plate and said light valve frame plate to temporarily fix said medial frame plate and said light valve frame plate.

9. The projection display device of claim 1,

said positioning member comprising a plurality of wedge members which are fixed with an adhesive.

10. The projection display device of claim 9,

said adhesive being a light-curable adhesive.

11. The projection display device of claim 1,

said light valve frame plate comprising a first frame plate and a second frame plate, said light valve being held between said first frame plate and said second frame plate.

12. The projection display device of claim 1,

said light valve being a liquid crystal light valve.

13. A light valve unit for positioning a light valve relative to the light incident face of a prism body, the light valve unit comprising:

a fixing frame plate for being fixed to a portion of said prism body with an adhesive;

a light valve frame plate for holding said light valve;

a fixing member that fixes said light valve frame plate on said fixing frame plate; and

a positioning member that fixes said light valve relative to said prism body;

said fixing frame plate comprising a material having a linear expansion coefficient ranging from one quarter to four times a linear expansion coefficient of said portion of said prism body.

14. The light valve unit of claim 13, said light valve frame plate comprising a material having a linear expansion coefficient ranging from one-fifth to five times that of a linear expansion coefficient of said fixing frame plate.

15. The light valve unit of claim 14, linear expansion coefficients E1, E2 and E3, of said portion of said prism body, said fixing frame plate and said light valve frame plate, respectively, satisfying the relationship of E3≧

E2≧

E1.

16. The light valve unit of claim 13, further comprising a medial frame plate between said fixing frame plate and said light valve frame plate, said medial frame plate fixed to said fixing frame plate by said fixing means and bonded to said light valve frame plate.

17. The light valve unit of claim 16, further comprising a temporary fixing member between said medial frame plate and said light valve frame plate, the temporary fixing member temporarily fixing said medial frame plate and said light valve frame plate.

18. The light valve unit of claim 13, said light valve frame plate comprising a first frame plate and a second frame plate holding said light valve between them.