Lighting apparatus and projection type display, and driving method therefor

• US 20090002313A1
• Filed: 07/21/2008
• Published: 01/01/2009
• Est. Priority Date: 10/09/2001
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Uchiyama, Shoichi, Iisaka, Hidehito
• Granted Patent: US 8,684,541 B2
• Time in Patent Office: Days
• US Class Current: 345/109
• CPC Class Codes: F21V 11/18 movable, e.g. flaps, slides
• CPC Class Codes: F21V 14/08 by movement of the screens or filters
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: H04N 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20

Abstract

A lighting apparatus used for a projection type display is provided, which can change the incident ray volume to an optical modulation device without changing the optical output intensity of the lamp, and can exhibit excellent effects in expressive power of an image and adaptability to the use environment. The lighting apparatus of the present invention comprises; a light source, two fly-eye lenses constituting a uniform lighting device, and a shading plate arranged between these fly-eye lenses and constituting a dimming device for adjusting the amount of light of the outgoing light from the light source. The angle of inclination of the shading plate is controlled based on an image signal supplied to the optical modulation device, thereby enabling adjustment of the amount of light.

Claims

1. A lighting apparatus used for lighting an optical modulation device in a projection type display, comprising:

a light source,

a uniform lighting device which equalizes the illuminance distribution of light shone from the light source, and

a shading plate for adjusting the amount of light emitted to the optical modulation device, the shading plate constructed such that at least a portion of light emitted from the light source is cut off,

the shaded area of the outgoing beam being adjusted by a movement of the shading plate,

the amount of light emitted to the optical modulation device being adjusted by controlling the shading plate based on the information from outside, and

the shading plate being constructed to be movable in a direction parallel with the principal plane thereof, and the amount of light being adjusted by the shift amount of the shading plate.

2. The lighting apparatus according to claim 1, the shading plate being arranged between the fly-eye lens and the convolution lens.

3. The lighting apparatus according to claim 1, the shading plate being arranged in the vicinity of the focal point of each lens constituting the fly-eye lens.

4. The lighting apparatus according to claim 1, the shading plate being arranged on the outgoing side of the convolution lens.

5. The lighting apparatus according to claim 1, the shading plate performing shading in linear symmetry with respect to each of the beams of light emitted from the fly-eye lenses.

6. The lighting apparatus according to claim 1, the shading plate performing shading centrosymmetrically with respect to each of the beams of light emitted from the fly-eye lenses.

7. The lighting apparatus according to claim 1, the shading plate performing shading in linear symmetry with respect to the center of a group of beams emitted from the fly-eye lenses.

8. The lighting apparatus according to claim 1, the shading plate performing shading centrosymmetrically with respect to the center of a group of beams emitted from the fly-eye lenses.

9. The lighting apparatus according to claim 6, further comprising:

another shading plate,

the two shading plates being arranged between adjacent beams of light emitted from the fly-eye lens, each of the shading plates has a slit opening provided perpendicularly to an optical axis of the light emitted from the light source, and

the two shading plates being movable in a direction parallel with the respective principal planes and in an opposite direction to each other.

10. The lighting apparatus according to claim 8, further comprising:

at least three shading plates,

the at least three shading plates being provided perpendicularly to an optical axis of the light emitted from the light source, one of the at least three shading plates being fixed in position, and

the remaining shading plates located at a position of linear symmetry with respect to the center of the group of beams emitted from the fly-eye lens being movable in an opposite direction to each other.

11. The lighting apparatus according to claim 1, the shading plate being arranged between the fly-eye lens and the light source.

14. The lighting apparatus according to claim 1, at least the surface on the side irradiated by the light, of the shading plate, having optical absorptivity.

15. The lighting apparatus according to claim 1, at least the surface on the side irradiated by the light, of the shading plate, having optical reflectivity.

12. The lighting apparatus according to claim 12, further comprising at least one shading plate, the shading plates being arranged along a plane perpendicular to an optical axis of the light emitted from the light source.

13. The lighting apparatus according to claim 13, the size of each of the plurality of shading plates or the pitch of the plurality of shading plates being different depending on the location.

16. The lighting apparatus according to claim 16, a light absorbing material for absorbing the reflected light being provided at a position where the reflected light from the shading plate reaches.

17. A projection type display, comprising:

a light source,

a uniform lighting device which equalizes the illuminance distribution of light shone from the light source, and

a shading plate for adjusting the amount of light emitted to the optical modulation device, the shading plate constructed such that at least a portion of light emitted from the light source is cut off,

an optical modulation device for modulating beams emitted from the light source, and

a projection device for projecting the beams modulated by the optical modulation device,

the shaded area of the outgoing beam being adjusted by a movement of the shading plate,

the amount of light emitted to the optical modulation device being adjusted by controlling the shading plate based on the information from outside, and

the shading plate being constructed to be movable in a direction parallel with the principal plane thereof, and the amount of light being adjusted by the shift amount of the shading plate.

18. A projection type display according to claim 18, further comprising:

a control signal determination device for determining a control signal which controls the shading plate based on an image signal;

a dimming control device for controlling the shading plate based on the control signal;

a dimming control device for controlling the shading plate based on the control signal; and

an image signal extension device for extending the image signal based on the control signal.

19. A driving method for a projection type display according to claim 18, a control signal for controlling the shading plate being determined based on an image signal, and the shading plate being controlled based on the control signal, to thereby adjust the amount of light which illuminates the optical modulation device, and to extend the image signal based on the control signal, and the extended image signal being supplied to the optical modulation device to thereby generate an image.