Illumination system and projector

• US 6,478,431 B1
• Filed: 11/02/2000
• Issued: 11/12/2002
• Est. Priority Date: 11/11/1999
• Status: Expired due to Fees

• Current Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Original Assignee: Minolta Corporation Limited (Konica Minolta Inc.)
• Inventors: Nagata, Hideki, Sawai, Yasumasa, Sawamura, Shigeru
• Primary Examiner(s): PERKEY, WILLIAM B
• Application Number:
  US09/705,044
• Time in Patent Office: 740 Days
• Field of Search: 353/81, 353/84, 353/98, 353/99, 348/743
• US Class Current: 353/81
• CPC Class Codes: G02B 26/008 in the form of devices for effecting sequential colour changes, e.g. colour wheels
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time

Abstract

An illumination system has a light source for emitting illumination light, a color wheel, a first deflecting member, and a second deflecting member. The color wheel transmits or reflects the illumination light while rotating about a rotation axis in such a way that illumination light exiting from the color wheel has colors that are switched sequentially with time. The first deflecting member deflects the illumination light in such a way that the illumination light enters the color wheel. The second deflecting member deflects the illumination light having exited from the color wheel. The illumination light entering the first deflecting member and the illumination light exiting from the second deflecting member are both substantially perpendicular to the rotation axis of the color wheel.

Claims

1. An illumination system comprising:

a light source for emitting illumination light;

a color wheel that reflects the illumination light while rotating about a rotation axis in such a way that illumination light exiting from the color wheel has colors that are switched sequentially with time;

a first deflecting member for deflecting the illumination light in such a way that the illumination light enters the color wheel; and

a second deflecting member for deflecting the illumination light having exited from the color wheel,

wherein the illumination light entering the first deflecting member and the illumination light exiting from the second deflecting member are both substantially perpendicular to the rotation axis of the color wheel.

2. An illumination system as claimed in claim 1,

wherein the color wheel is of a reflection type.

3. An illumination system as claimed in claim 1,

wherein at least one of the first and second deflecting members is a flat mirror.

4. An illumination system as claimed in claim 1,

wherein at least one of the first and second deflecting members is a prism having a mirror-reflection surface.

5. An illumination system as claimed in claim 1,

wherein at least one of the first and second deflecting members is a prism having a total-reflection surface.

6. An illumination system as claimed in claim 1,

wherein the first and the second deflecting members are TIR prisms.

7. An illumination system as claimed in claim 1,

wherein an integrator rod is disposed in an optical path.

8. An illumination system as claimed in claim 1,

wherein the light source is a combination of a lamp and a paraboloid mirror serving as a reflector.

9. An illumination system as claimed in claim 8,

wherein the reflector further includes a flat mirror.

10. An illumination system as claimed in claim 1,

wherein the light source is a combination of a lamp and an ellipsoid mirror serving as a reflector.

11. An illumination system as claimed in claim 10,

wherein the reflector further includes a spherical mirror.

12. An illumination system comprising:

a light source for emitting illumination light;

a color wheel that transmits the illumination light while rotating about a rotation axis in such a way that illumination light exiting from the color wheel has colors that are switched sequentially with time;

a first deflecting member for deflecting the illumination light in such a way that the illumination light enters the color wheel, and

a second deflecting member for deflecting the illumination light having exited from the color wheel,

wherein the illumination light deflected by the first deflecting member is substantially equivalent to the illumination light received by the color wheel;

wherein the illumination light entering the first deflecting member and the illumination light exiting from the second deflecting member are both substantially perpendicular to the rotation axis of the color wheel; and

wherein the color wheel is of a transmission type.

13. An illumination system as claimed in claim 12,

wherein at least one of the first and second deflecting members is a flat mirror.

14. An illumination system as claimed in claim 12,

wherein at least one of the first and second deflecting members is a prism having a mirror-reflection surface.

15. An illumination system as claimed in claim 12,

wherein at least one of the first and second deflecting members is a prism having a total-reflection surface.

16. An illumination system as claimed in claim 12,

wherein the first and the second deflecting members are TIR prisms.

17. An illumination system as claimed in claim 12,

wherein an integrator rod is disposed in an optical path.

18. An illumination system as claimed in claim 12,

wherein the light source is a combination of a lamp and a paraboloid mirror serving as a reflector.

19. An illumination system as claimed in claim 18,

wherein the reflector further includes a flat mirror.

20. An illumination system as claimed in claim 12,

wherein the light source is a combination of a lamp and an ellipsoid mirror serving as a reflector.

21. An illumination system as claimed in claim 20,

wherein the reflector further includes a spherical mirror.

22. A projector comprising:

a light source for emitting illumination light;

a color wheel that transmits or reflects the illumination light while rotating about a rotation axis in such a way that illumination light exiting from the color wheel has colors that are switched sequentially with time;

a first deflecting member for deflecting the illumination light in such a way that the illumination light enters the color wheel;

a second deflecting member for deflecting the illumination light having exited from the color wheel,

a spatial light modulation device that is illuminated with the illumination light exiting from the color wheel and that modulates illumination light so as to emit the modulated illumination light as an image light; and

a projection optical system for projecting the image light modulated by the spatial light modulation device onto a projection surface located at a predetermined distance,

wherein the rotation axis of the color wheel and an optical axis of the projection optical system are substantially perpendicular to each other; and

wherein the illumination light entering the first deflecting member and the illumination light exiting from the second deflecting member are both substantially perpendicular to the rotation axis of the color wheel.

23. A projector as claimed in claim 22,

wherein the spatial light modulation device is a reflection-type liquid crystal display device.

24. A projector as claimed in claim 22,

wherein the spatial light modulation device is a Digital Micromirror Device™

.

25. A projector as claimed in claim 22,

wherein the rotation axis of the color wheel and an optical axis of the projection optical system are substantially perpendicular to each other.

26. A projector comprising:

a light source for emitting illumination light;

a color wheel that reflects the illumination light while rotating about a rotation axis in such a way that illumination light exiting from the color wheel has colors that are switched sequentially with time;

a first deflecting member for deflecting the illumination light in such a way that the illumination light enters the color wheel,

a second deflecting member for deflecting the illumination light reflected from the color wheel,

a spatial light modulation device that is illuminated with the illumination light exiting from the color wheel and that modulates illumination light so as to emit the modulated illumination light as an image light; and

a projection optical system for projecting the image light modulated by the spatial light modulation device onto a projection surface located at a predetermined distance,

wherein the illumination light entering the first deflecting member and the illumination light exiting from the second deflecting member are both substantially perpendicular to the rotation axis of the color wheel.

27. A projector comprising:

a light source for emitting illumination light;

a color wheel that transmits the illumination light while rotating about a rotation axis in such a way that illumination light exiting from the color wheel has colors that are switched sequentially with time;

a first deflecting member for deflecting the illumination light in such a way that the illumination light enters the color wheel;

a second deflecting member for deflecting the illumination light having exited from the color wheel,

a spatial light modulation device that is illuminated with the illumination light exiting from the color wheel and that modulates illumination light so as to emit the modulated illumination light as an image light; and

a projection optical system for projecting the image light modulated by the spatial light modulation device onto a projection surface located at a predetermined distance,

wherein the illumination light deflected by the first deflecting member is substantially equivalent to the illumination light received by the color wheel;

wherein the illumination light entering the first deflecting member and the illumination light exiting from the second deflecting member are both substantially perpendicular to the rotation axis of the color wheel; and

wherein the color wheel is of a transmission type.