Lighting apparatus and projection type display, and driving method therefor

• US 20050270268A1
• Filed: 08/01/2005
• Published: 12/08/2005
• 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 7,417,618 B2
• Time in Patent Office: Days
• US Class Current: 345/108
• 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 said light source, and a dimming device for adjusting the amount of light emitted from said light source, which is arranged on an optical axis of the light emitted from said light source, wherein said dimming device comprises a shading plate constructed such that at least a portion of light emitted from said light source is cut off, and the shaded area of the outgoing beam by a movement of the shading plate is adjusted, and wherein the amount of light emitted from said uniform lighting device is adjusted by controlling said dimming device based on the information from outside.

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

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

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

5. The lighting apparatus according to claim 1, wherein said shading plate is constructed so as to be movable in a direction parallel with the principal plane thereof, and the amount of light is adjusted by the shift amount of said shading plate.

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

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

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

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

10. The lighting apparatus according to claim 6, further comprising another shading plate, wherein said two shading plates are arranged between adjacent beams of light emitted from said fly-eye lens, each of the shading plates has a slit opening provided perpendicularly to said optical axis, and said two shading plates are movable in a direction parallel with the respective principal planes and in an opposite direction to each other.

11. The lighting apparatus according to claim 8, further comprising at least two shading plates, wherein said at least three shading plates are provided perpendicularly to said optical axis, one of said at least three shading plates is 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 said fly-eye lens are movable in an opposite direction to each other.

12. The lighting apparatus according to claim 1, wherein said shading plate is arranged between said fly-eye lens and said light source.

13. The lighting apparatus according to claim 12, further comprising at least one shading plate, wherein said shading plates are arranged along a plane perpendicular to said optical axis.

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

15. The lighting apparatus according to claim 1, wherein at least the surface on the side irradiated by the light, of said shading plate, has optical absorptivity.

16. The lighting apparatus according to claim 1, wherein at least the surface on the side irradiated by the light, of said shading plate, has optical reflectivity.

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

18. A projection type display having a lighting device, an optical modulation device for modulating beams emitted from said lighting device, and a projection device for projecting the beams modulated by said optical modulation device, which comprises a lighting apparatus according to claim 1, as said lighting device.

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

a control signal determination device for determining a control signal which controls said dimming device based on an image signal;

a dimming control device for controlling said dimming device based on said control signal; and

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

20. A driving method for a projection type display according to claim 18, wherein a control signal for controlling said dimming device is determined based on an image signal, and said dimming device is controlled based on said control signal, to thereby adjust the amount of light which illuminates said optical modulation device, and to extend said image signal based on said control signal, and this extended image signal is supplied to said optical modulation device to thereby generate an image.