Illumination apparatus and video projection display system

• US 7,303,291 B2
• Filed: 03/25/2005
• Issued: 12/04/2007
• Est. Priority Date: 03/31/2004
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Ikeda, Takashi, Arai, Kazuhiro
• Primary Examiner(s): KOVAL, MELISSA J
• Application Number:
  US11/088,722
• Publication Number:
  US 20050219847A1
• Time in Patent Office: 984 Days
• Field of Search: 353/20, 353/33, 353/34, 353/94, 353/97, 353/102, 353/31, 353/69, 353/70, 353/81, 353/99, 349/8, 349/9, 362/231, 362/331, 362/227, 362/551, 359/642, 359/649
• US Class Current: 353/102
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/1033 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• 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

An illumination apparatus includes: a group of light source segments; a group of condenser lenses arrayed as opposed to the group of light source segments, and a group of rectangular lens elements arrayed as opposed to the group of condenser lenses for converging a light ray transmitted through the opposing condenser lens; and an illumination optical system for guiding the rays to an illumination plane. The lens elements have a shape of a rectangle and are arrayed in a rectangular effective area in such a way that a longitudinal axis of each lens elements intersects an axis passing a side of the effective area at 45°.

Claims

1. An illumination apparatus comprising:

a light source including a group of light source segments arranged in an array;

a lens array including a group of condenser lenses arrayed as opposed to the group of light source segments, and a group of lens elements arrayed as opposed to the group of condenser lenses, each of the lens elements converging a light ray that has been generated in the opposing light source segment and has been transmitted through the opposing condenser lens; and

an illumination optical system which guides the rays that have been transmitted through the lens elements in such a manner that the rays fall an illumination plane at a predetermined angle of incidence,

wherein the lens elements are arrayed in a rectangular effective area with a clearance from each other, the effective area being defined by the illumination optical system as an area capable of arranging the lens elements and having a shape of a rectangle whose one side extends along an X-axis, and each of the lens elements having a shape of a rectangle whose longitudinal axis intersects the X-axis at 45°

, and an aspect ratio of each of the lens elements is less than 2, and the lens elements are arrayed along two sides of the effective area orthogonal to each other with a pitch of √

2·

V where V represents a length of a shorter side of each of the lens elements.

2. The illumination apparatus according to claim 1, wherein the light source segments are arrayed with the same pitch as the lens elements.

3. The illumination apparatus according to claim 1, wherein the condenser lenses are arrayed with the same pitch as the lens elements.

4. The illumination apparatus according to claim 1, wherein the group of lens elements is an integrally molded product.

5. The illumination apparatus according to claim 1, wherein each of the condenser lenses is constituted of plural lens elements opposing to each other so that the group of condenser lenses has a plurality of layers each formed of a lens element array, and at least one of the layers is an integrally molded product.

6. The illumination apparatus according to claim 1,

wherein the light source includes

a first light source, a second light source, and a third light source which generate light rays of three colors having different wavelengths from each other, respectively;

and

wherein the illumination optical system includes

a color synthesizing unit which is arranged on an optical path from the first, the second, and the third light sources up to the illumination plane to synthesize the rays of three colors.

7. The illumination apparatus according to claim 6, wherein the three colors are red, green, and blue.

8. The illumination apparatus according to claim 6, further comprising a light source controller which successively tums on the first, the second, and the third light sources by timesharing.

9. The illumination apparatus according to claim 1, wherein the light source segment includes a light emitting diode.

10. The illumination apparatus according to claim 1, wherein the light source segment includes a laser light source.

11. A video projection display system comprising:

the illumination apparatus of claim 1;

a light valve which is arranged on the illumination plane of the illumination apparatus; and

a projection optical system which projects an outgoing ray from the light valve.

12. The video projection display system according to claim 11, wherein the light valve includes a micro deflection mirror optical device.

13. The video projection display system according to claim 12, wherein the light valve includes a digital micro mirror device.

14. An illumination apparatus comprising:

a light source including a group of light source segments arranged in an array;

a lens array including a group of condenser lenses arrayed as opposed to the group of light source segments, and a group of lens elements arrayed as opposed to the group of condenser lenses, each of the lens elements converging a light ray that has been generated in the opposing light source segment and has been transmitted through the opposing condenser lens; and

an illumination optical system which guides the rays that have been transmitted through the lens elements in such a manner that the rays fall an illumination plane at a predetermined angle of incidence,

wherein the lens elements are arrayed in a rectangular effective area with a clearance from each other, the effective area being defined by the illumination optical system as an area capable of arranging the lens elements and having a shape of a rectangle whose one side extends along an X-axis, and each of the lens elements having a shape of a rectangle whose longitudinal axis intersects the X-axis at 45°

, and an aspect ratio of each of the lens elements is more than 2, and the lens elements are arrayed along two sides of the effective area orthogonal to each other with a pitch of (1/√

2)·

H where H represents a length of a longer side of each of the lens elements.

15. The illumination apparatus according to claim 14, wherein the light source segments are arrayed with the same pitch as the lens elements.

16. The illumination apparatus according to claim 14, wherein the condenser lenses are arrayed with the same pitch as the lens elements.

17. The illumination apparatus according to claim 14, wherein the group of lens elements is an integrally molded product.

18. The illumination apparatus according to claim 14, wherein each of the condenser lenses is constituted of plural lens elements opposing to each other so that the group of condenser lenses has plurality of layers each formed of a lens element array, and at least one of the layers is an integrally molded product.

19. The illumination apparatus according to claim 14,

wherein the light source includes

a first light source, a second light source, and a third light source which generate light rays of three colors having different wavelengths from each other, respectively;

and

wherein the illumination optical system includes

a color synthesizing unit which is arranged on an optical path from the first, the second, and the third light sources up to the illumination plane to synthesize the rays of three colors.

20. The illumination apparatus according to claim 19, wherein the three colors are red, greed, and blue.

21. The illumination apparatus according to claim 19, further comprising a light source controller which successively turns on the first, the second, and the third light sources by timesharing.

22. The illumination apparatus according to claim 14, wherein the light source segment includes a light emitting diode.

23. The illumination apparatus according to claim 14, wherein the light source segment includes a laser light source.

24. A video projection display system comprising:

the illumination apparatus of claim 14;

a light valve which is arranged on the illumination plane of the illumination apparatus; and

a projection optical system which projects an outgoing ray from the light valve.

25. The video projection display system according to claim 24, wherein the light valve includes a micro deflection mirror optical device.

26. The video projection display system according to claim 25, wherein the light valve includes a digital micro mirror device.

27. An illumination apparatus comprising:

a light source including a group of light source segments arranged in an array;

a lens array including a group of condenser lenses arrayed as opposed to the group of light source segments, and a group of lens elements arrayed as opposed to the group of condenser lenses, each of the lens elements converging a light ray that has been generated in the opposing light source segment and has been transmitted through the opposing condenser lens; and

an illumination optical system which guides the rays that have been transmitted through the lens elements in such a manner that the rays fall an illumination plane at a predetermined angle of incidence,

wherein the lens elements are arrayed in a rectangular effective area, the effective area being defined by the illumination optical system as an area capable of arranging the lens elements and having a shape of a rectangle whose one side extends along an X-axis, and each of the lens elements having a shape of a rectangle whose longitudinal axis interests the X-axis at 45°

, and

wherein an aspect ratio of each of the lens elements is 2, and the lens elements are arrayed along two sides of the effective area orthogonal to each other with a pitch of √

2·

V where V represents a length of a shorter side of each of the lens elements.

28. The illumination apparatus according to claim 27, wherein the light source segments are arrayed with the same pitch as the lens elements.

29. The illumination apparatus according to claim 27, wherein the condenser lenses are arrayed with the same pitch as the lens elements.

30. The illumination apparatus according to claim 27, wherein the group of lens elements is an integrally molded product.

31. A video projection display system comprising:

the illumination apparatus of claim 27;

a light valve which is arranged on the illumination plane of the illumination apparatus; and

a projection optical system which projects an outgoing ray from the light valve.