Optical modulation device and projection display device utilizing the optical modulation device

• US 6,359,721 B1
• Filed: 08/31/1999
• Issued: 03/19/2002
• Est. Priority Date: 09/09/1998
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Fujimori, Motoyuki
• Primary Examiner(s): MAI, HUY KIM
• Application Number:
  US09/386,372
• Time in Patent Office: 931 Days
• Field of Search: 359/237, 359/248, 359/245, 359/246, 359/249, 359/259, 349/5, 349/8, 349/9, 349/161, 349/FOR.124, 349/FOR.125
• US Class Current: 359/246
• CPC Class Codes: G02F 1/133385 with cooling means, e.g. fans
• 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 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3144 Cooling systems cooling of liquid crystal cells in general G02F1/133382; cooling of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/16

Abstract

An optical modulation device which can facilitate a reduction in size of a device and prevent overheating of the optical modulation device, and a projection display device utilizing the optical modulation device are provided. In the optical modulation device, sapphire glasses are affixed to the light-incident side and the light-emitting side surfaces of liquid crystal panels which respectively modulates light of three colors of red, green, and blue emitted from a light source according to image information. Therefore, heat generated on optical modulation devices can be discharged, so that overheating of the optical modulation devices can be prevented, and a reduction in size can be achieved. In addition, since the sapphire glass is difficult to scratch, it becomes easy-to-handle, thereby facilitating the management of the optical modulation devices.

Claims

1. An optical modulation device comprising:

an electro-optical device having a light-incident side and a light-emitting side that modulates light emitted from a light source according to image information;

a sapphire glass affixed to at least one surface of the light-incident side and the light-emitting side of said electro-optical device; and

a projection lens having a focal depth, said sapphire glass thickness being larger than the focal depth of said projection lens.

2. The optical modulation device according to claim 1, said sapphire glass being affixed to a surface of the light-incident side of said electro-optical device.

3. The optical modulation device according to claim 1, further comprising:

a frame that holds said electro-optical device; and

a metal film provided on a contact portion between the frame and said sapphire glass.

4. The optical modulation device according to claim 3, said frame comprising two frames that hold said electro-optical device from a side of a light-incident surface and a side of a light-emitting surface, and at least one of said frames being formed of a material including magnesium as a principal material.

5. The optical modulation device according to claim 3, further comprising heat-dissipating fins provided on said frame.

6. The optical modulation device according to claim 5, said fins being provided along a flow of cooling air for cooling said electro-optical device and a vicinity of said electro-optical device.

7. The optical modulation device according to claim 3, further comprising a graphite sheet provided on said frame that transmits heat from said frame to another part.

8. The optical modulation device according to claim 7, said graphite sheet is being in contact with a metallic part.

9. The optical modulation device according to claim 1, further comprising polarizers arranged on the light-incident side and the light-emitting side of said electro-optical device, at least one of the polarizers being arranged at a position apart from one of said electro-optical device and said sapphire glass.

10. A projection display device comprising:

three optical modulation devices that respectively modulate red light, green light, and blue light according to image information, each of said optical modulation devices having an electro-optical device which includes a light-incident side and a light-emitting side;

a sapphire glass affixed to at least one surface of the light-incident side and the light-emitting side of said electro-optical device in said optical modulation device for modulating at least the blue light; and

a projection lens having a focal depth, said sapphire glass having a thickness larger than the focal depth of said projection lens.

11. The projection display device according to claim 10, said sapphire glass being affixed to a surface of the light-incident side of said electro-optical device.

12. The projection display device according to claim 10, said optical modulation devices comprising a frame that holds said electro-optical device, and a metal film provided on a contact portion between the frame and said sapphire glass.

13. The projection display device according to claim 12, said frame comprising two frames that hold said electro-optical device from a side of a light-incident surface and a side of a light-emitting surface, at least one of said frames being formed of a material including magnesium as a principal material.

14. The projection display device according to claim 12, further comprising heat-dissipating fins provided on said frame.

15. The projection display device according to claim 14, said fins being provided along a flow of cooling air for cooling said electro-optical device and a vicinity of said electro-optical device.

16. The projection display device according to claim 12, further comprising a graphite sheet provided on said frame that transmits heat from said frame to another part.

17. The projection display device according to claim 16, said graphite sheet being in contact with a metallic part.

18. The projection display device according to claim 10, further comprising polarizers arranged on the light-incident side and the light-emitting side of said electro-optical device, at least one of the polarizers being arranged at a position apart from one of said electro-optical device and said sapphire glass.

19. An optical modulation device, comprising:

an electro-optical device that modulates light emitted from a light source according to image information, said electro-optical device having a pair of substrates, at least one of said substrates being made of sapphire glass having a thickness; and

a projection lens having a focal depth, said sapphire glass having a thickness larger than the focal depth of said projection lens.

20. The optical modulation device according to claim 19, further comprising:

a frame that holds said electro-optical device; and

a metal film provided on a contact portion between the frame and said sapphire glass.

21. The optical modulation device according to claim 20, said frame comprising two frames that hold said electro-optical device from a side of a light-incident surface and a side of a light-emitting surface, and at least one of said frames being formed of a material including magnesium as a principal material.

22. The optical modulation device according to claim 20, further comprising heat-dissipating fins provided on said frame.

23. The optical modulation device according to claim 22, said fins being provided along a flow of cooling air for cooling said electro-optical device and a vicinity of said electro-optical device.

24. The optical modulation device according to claim 20, further comprising a graphite sheet provided on said frame that transmits heat from said frame to another part.

25. The optical modulation device according to claim 24, said graphite sheet is being in contact with a metallic part.

26. The optical modulation device according to claim 19, further comprising polarizers arranged on the light-incident side and the light-emitting side of said electro-optical device, at least one of the polarizers being arranged at a position apart from one of said electro-optical device and said sapphire glass.

27. The optical modulation device according to claim 19, further comprising a projector lens having a focal depth and at least one of the substrates being made of sapphire glass having a thickness larger than the focal depth of said projection lens.

28. A projection display device, comprising:

three optical modulation devices that respectively modulate red light, green light, and blue light according to image information, each of said optical modulation devices having an electro-optical device, and said electro-optical device having a pair of substrates, at least one of said substrates of said electro-optical device in said optical modulation device that modulates at least the blue light being made of sapphire glass;

and a projection lens having a focal depth, said sapphire glass having a thickness larger than the focal depth of said projection lens.

29. The projection display device according to claim 28, said optical modulation devices comprising a frame that holds said electro-optical device, and a metal film provided on a contact portion between the frame and said sapphire glass.

30. The projection display device according to claim 29, said frame comprising two frames that hold said electro-optical device from a side of a light-incident surface and a side of a light-emitting surface, at least one of said frames being formed of a material including magnesium as a principal material.

31. The projection display device according to claim 29, further comprising heat-dissipating fins provided on said frame.

32. The projection display device according to claim 31, said fins being provided along a flow of cooling air for cooling said electro-optical device and a vicinity of said electro-optical device.

33. The projection display device according to claim 29, further comprising a graphite sheet provided on said frame that transmits heat from said frame to another part.

34. The projection display device according to claim 33, said graphite sheet being in contact with a metallic part.

35. The projection display device according to claim 28, further comprising polarizers arranged on the light-incident side and the light-emitting side of said electro-optical device, at least one of the polarizers being arranged at a position apart from one of said electro-optical device and said sapphire glass.