Projection display device

• US 20100271598A1
• Filed: 04/12/2010
• Published: 10/28/2010
• Est. Priority Date: 04/23/2009
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Murayama, Kazuaki, Miyazaki, Kanto
• Granted Patent: US 8,770,763 B2
• Time in Patent Office: Days
• US Class Current: 353/38
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G02B 27/1033 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/1053 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light

Abstract

A projection display device which displays an image by projecting the image on a screen includes a laser light source for emitting coherent light, a display device for forming an image to be displayed on a screen in an area illuminated by a luminous flux from the laser light source, a first diffusion plate for diffusing a luminous flux, and a second diffusion plate for diffusing a luminous flux. The first diffusion plate is provided in at least one of a conjugate position of the laser light source or the vicinity of the conjugate position in the optical path of the optical system including the laser light source through the screen. The second diffusion plate is provided in at least one of a conjugate position of the display device and the vicinity of the conjugate position.

Claims

1. A projection display device which displays an image by projecting the image on a screen, comprising:

at least one light source outputting coherent light;

a display device forming an image to be displayed on the screen in an area illuminated by a luminous flux from the light source;

a first diffusion unit diffusing the luminous flux; and

a second diffusion unit diffusing the luminous flux, wherein;

the first diffusion unit is provided in at least one of a light source conjugate position and the vicinity of the position in an optical path of an optical system including the light source through the screen; and

the second diffusion unit is provided in at least one of a display device conjugate position and the vicinity of the position in the optical path of the optical system.

2. The device according to claim 1, wherein:

an optical system including the light source through the screen comprises;

an optical system for illumination propagating the luminous flux emitted from the light source into a predetermined optical path and leading the luminous flux toward the screen; and

an optical system for projection scaling up and projecting the image formed in the illuminated area of the display device;

the display device forms an image to be displayed on the screen in the area illuminated by the luminous flux lead by the optical system for illumination;

the first diffusion unit is provided in at least one of the light source conjugate position and the vicinity of the conjugate position in the optical path of the optical system for illumination; and

the second diffusion unit is provided in at least one of the display device conjugate position and the vicinity of the conjugate position in the optical path of the optical system for illumination.

3. The device according to claim 2, further comprising

a luminous flux intensity leveling unit leveling intensity of a luminous flux, wherein:

the luminous flux intensity leveling unit is provided in the optical system for illumination, a luminous flux incident surface of the luminous flux intensity leveling unit has a conjugate relationship with the light source, a luminous flux emission surface of the luminous flux intensity leveling unit has a conjugate relationship with the display device;

the first diffusion unit is provided in the position of the luminous flux incident surface or the vicinity of the position; and

the second diffusion unit is provided in the position of the luminous flux emission surface or the vicinity of the position.

5. The device according to claim 1, wherein

at least one of the first diffusion unit and the second diffusion unit is an optical diffusion device capable of arbitrarily forming a diffusion angle and a luminous intensity distribution form acquired when a luminous flux is transmitted.

7. The device according to claim 5, wherein

the diffusion angle of the optical diffusion device is 10°

through 40°

.

9. The device according to claim 3, wherein

the luminous flux intensity leveling unit, the first diffusion unit and the second diffusion unit are configured in a unitary construction.

11. The device according to claim 3, wherein

the luminous flux intensity leveling unit is a rod integrator.

13. The device according to claim 1, wherein

the display device reflects a luminous flux and forms an image.

15. The device according to claim 1, wherein

the display device transmits a luminous flux and forms an image.

4. A projection display device which displays an image by projecting the image on a screen, comprising:

at least one light source outputting coherent light;

an optical system for illumination propagating the luminous flux emitted from the light source into a predetermined optical path and leading the luminous flux toward the screen;

a display device forming the image to be displayed on the screen in an area illuminated by a luminous flux led by the optical system for illumination;

an optical system for projection scaling up and projecting the image formed in the illuminated area of the display device;

a first diffusion unit diffusing a luminous flux;

a second diffusion unit diffusing a luminous flux; and

a luminous flux intensity leveling unit leveling intensity of the luminous flux, wherein;

the luminous flux intensity leveling unit is provided in the optical system for illumination;

the first diffusion unit is provided in a position of a luminous flux incident surface of the luminous flux intensity leveling unit or vicinity of the luminous flux incident surface; and

the second diffusion unit is provided in a position of a luminous flux emission surface of the luminous flux intensity leveling unit or vicinity of the luminous flux emission surface.

6. The device according to claim 4, wherein

at least one of the first diffusion unit and the second diffusion unit is an optical diffusion device capable of arbitrarily forming a diffusion angle and a luminous intensity distribution form acquired when a luminous flux is transmitted.

8. The device according to claim 6, wherein

the diffusion angle of the optical diffusion device is 10°

through 40°

.

10. The device according to claim 4, wherein

the luminous flux intensity leveling unit, the first diffusion unit and the second diffusion unit are configured in a unitary construction.

12. The device according to claim 4, wherein

the luminous flux intensity leveling unit is a rod integrator.

14. The device according to claim 4, wherein

the display device reflects a luminous flux and forms an image.

16. The device according to claim 4, wherein

the display device transmits a luminous flux and forms an image.