Illumination apparatus and image projection apparatus using the illumination apparatus

• US 7,185,985 B2
• Filed: 09/09/2003
• Issued: 03/06/2007
• Est. Priority Date: 09/12/2002
• Status: Expired due to Fees

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: Hanano, Kazunari
• Primary Examiner(s): KOVAL, MELISSA J
• Application Number:
  US10/657,978
• Publication Number:
  US 20040062044A1
• Time in Patent Office: 1,274 Days
• Field of Search: 353/20, 353/30, 353/31, 353/102, 353/34, 362/558
• US Class Current: 353/30
• CPC Class Codes: G02B 27/0927 Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/2066 Reflectors in illumination beam in projection beam G03B21/28
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• 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 comprises a small-plane light source having diffusion radiation characteristics, a columnar light leading member, having an incident end surface, an outgoing radiation end surface and a reflection surface, configured to reflect on the reflection surface at least a part of a light ray from the small-plane light source collected from the incident end surface, thereby leading the light to the outgoing radiation end surface, and an angle position converting member configured to convert an outgoing light angle intensity of the outgoing light from the outgoing radiation end surface of the columnar light leading member into a position intensity in a predetermined irradiation area.

Claims

1. An illumination apparatus comprising:

a small-plane light source having diffusion radiation characteristics;

a columnar light leading member, having an incident end surface, an outgoing radiation end surface and a reflection surface, configured to reflect on the reflection surface at least a part of a light ray from the small-plane light source collected from the incident end surface, thereby leading the light to the outgoing radiation end surface; and

an angle position converting member configured to convert an outgoing light angle intensity of the outgoing light from the outgoing radiation end surface of the columnar light leading member into a position intensity in a predetermined irradiation area, wherein a distance between the angle position converting member and the predetermined irradiation area is substantially equal to a focal distance of the angle position converting member.

2. The apparatus according to claim 1, wherein

the angle position converting member includes a pupil forming member configured to form a pupil by using the outgoing radiation end surface of the columnar light leading member as a virtual light source, and

a position of the irradiation area is set in the vicinity of a position of a pupil formed by the pupil forming member.

3. The apparatus according to claim 2, wherein

the pupil forming member includes an illumination lens configured to condense the light from the outgoing radiation end surface of the columnar light leading member, and

the predetermined irradiation area is set in the vicinity of a focal position of the illumination lens.

4. The apparatus according to claim 2, wherein an outgoing light beam angle of the columnar light leading member is configured to substantially match with an incident side numerical aperture when forming a pupil with a predetermined size by the pupil forming member.

5. The apparatus according to claim 1, wherein the columnar light leading member has a tapered shape such that an area of the outgoing radiation end surface is larger than an area of the incident end surface.

6. The apparatus according to claim 5, wherein the columnar light leading member has an anisotropy in a ratio of a size of the incident end surface and a size of the outgoing radiation end surface, and

one of a ratio of lengths measured in a horizontal direction and a ratio of lengths measured in a vertical direction of the outgoing radiation end surface relative to the incident end surface of the columnar light leading member is larger than the other, and

the outgoing radiation end surface of the columnar light leading member is positioned at a focal point such that an extent of the illuminated area differs in the horizontal and vertical directions such that the direction of a larger extent of light in the illuminated area is similar to the direction of the smaller size ratio in the columnar light leading member.

7. The apparatus according to claim 5, wherein the incident end surface and the outgoing radiation end surface of the columnar light leading member have shapes similar to each other.

8. The apparatus according to claim 1, wherein the columnar light leading member includes a rod constituted by an optical plane made of a transparent material.

9. The apparatus according to claim 1, wherein the columnar light leading member includes a mirror pipe having a hollow structure whose inner surface is constituted by a reflecting mirror.

10. The apparatus according to claim 1, wherein the columnar light leading member has an anisotropy in a ratio of a size of the incident end surface and a size of the outgoing radiation end surface, and

one of a ratio of lengths measured in a horizontal direction and a ratio of lengths measured in a vertical direction of the outgoing radiation end surface relative to the incident end surface of the columnar light leading member is larger than the other, and

the outgoing radiation end surface of the columnar light leading member is positioned at a focal point such that an extent of the illuminated area differs in the horizontal and vertical directions such that the direction of a larger extent of light in the illuminated area is similar to the direction of the smaller size ratio in the columnar light leading member.

11. The apparatus according to claim 1, wherein the incident end surface and the outgoing radiation end surface of the columnar light leading member have shapes similar to each other.

12. The apparatus according to claim 1 wherein the incident end surface and outgoing radiation end surface are planar surfaces.

13. An image projection apparatus comprising:

an illumination apparatus comprising;

a small-plane light source having diffusion radiation characteristics;

a columnar light leading member, having an incident end surface, an outgoing radiation end surface and a reflection surface, configured to reflect on the reflection surface at least a part of a light ray from the small-plane light source collected from the incident end surface, thereby leading the light to the outgoing radiation end surface; and

an angle position converting member configured to convert an outgoing light angle intensity of the outgoing light from the outgoing radiation end surface of the columnar light leading member into a position intensity in a predetermined irradiation area;

a light modulation element, having a pixel structure, configured to modulate a light ray for each pixel in accordance with an image signal; and

a projection lens configured to enlarge and project the light modulation element, wherein

the light modulation element is arranged in the illumination area in the illumination apparatus and the distance between the outgoing radiation end surface and the angle position converting member and the distance between the angle position converting member and the light modulation element are substantially equal.

14. The apparatus according to claim 13, wherein

the angle position converting member includes a pupil forming member configured to form a pupil by using the outgoing radiation end surface of the columnar light leading member as a virtual light source, and

a position of the irradiation area is set in the vicinity of a position of a pupil formed by the pupil forming member.

15. The apparatus according to claim 14, wherein

the pupil forming member includes an illumination lens configured to condense the light from the outgoing radiation end surface of the columnar light leading member, and

the predetermined irradiation area is set in the vicinity of a focal position of the illumination lens.

16. The apparatus according to claim 14, wherein an outgoing light beam angle of the columnar light leading member is configured to substantially match an incident side numerical aperture when forming a pupil with a predetermined size by the pupil forming member.

17. The apparatus according to claim 13, wherein the columnar light leading member has a tapered shape such that an area of the outgoing radiation end surface is larger than an area of the incident end surface.

18. The apparatus according to claim 17, wherein the columnar light leading member has an anisotropy in a ratio of a size of the incident end surface and a size of the outgoing radiation end surface, and

one of a ratio of lengths measured in a horizontal direction and a ratio of lengths measured in a vertical direction of the outgoing radiation end surface relative to the incident end surface of the columnar light leading member is larger than the other, and

the outgoing radiation end surface of the columnar light leading member is positioned at a focal point such that an extent of the illuminated area differs in the horizontal and vertical directions such that the direction of a larger extent of light in the illuminated area is similar to the direction of the smaller size ratio in the columnar light leading member.

19. The apparatus according to claim 17, wherein the incident end surface and the outgoing radiation end surface of the columnar light leading member have shapes similar to each other.

20. The apparatus according to claim 13, wherein the columnar light leading member includes a rod constituted by an optical plane made of a transparent material.

21. The apparatus according to claim 13, wherein the columnar light leading member includes a mirror pipe having a hollow structure whose inner surface is constituted by a reflecting mirror.

22. The apparatus according to claim 13, wherein the columnar light leading member has an anisotropy in a ratio of a size of the incident end surface and a size of the outgoing radiation end surface, and

one of a ratio of lengths measured in a horizontal direction and a ratio of lengths measured in a vertical direction of the outgoing radiation end surface relative to the incident end surface of the columnar light leading member is larger than the other, and

the outgoing radiation end surface of the columnar light leading member is positioned at a focal point such that an extent of the illuminated area differs in the horizontal and vertical directions such that the direction of a larger extent of light in the illuminated area is similar to the direction of the smaller size ratio in the columnar light leading member.

23. The apparatus according to claim 13, wherein the incident end surface and the outgoing radiation end surface of the columnar light leading member have shapes similar to each other.

24. The apparatus according the claim 13, wherein said distance is a focal length distance.

25. The apparatus according to claim 13, wherein the incident end surface and outgoing radiation end surface are planar surfaces.

26. An illumination apparatus comprising:

a small-plane light source having diffusion radiation characteristics;

columnar light leading means, having an incident end surface, an outgoing radiation end surface and a reflection surface, for reflecting on the reflection surface at least a part of a light ray from the small-plane light source collected from the incident end surface, thereby leading the light to the outgoing radiation end surface; and

angle position converting means for converting an outgoing light angle intensity of the outgoing light from the outgoing radiation end surface of the columnar light leading means into a position intensity in a predetermined irradiation area and the distance between the outgoing radiation end surface and the angle position converting means and the distance between the angle position converting means and the light modulation element are substantially equal.

27. An image projection apparatus comprising:

an illumination apparatus comprising;

a small-plane light source having diffusion radiation characteristics;

columnar light leading means, having an incident end surface, an outgoing radiation end surface and a reflection surface, for reflecting on the reflection surface at least a part of a light ray from the small-plane light source collected from the incident end surface, thereby leading the light to the outgoing radiation end surface; and

angle position converting means for converting an outgoing light angle intensity of the outgoing light from the outgoing radiation end surface of the columnar light leading means into a position intensity in a predetermined irradiation area;

a light modulation element, having a pixel structure, for modulating a light ray for each pixel in accordance with an image signal; and

a projection lens for enlarging and projecting the light modulation element, wherein

the light modulation element is arranged in the illumination area in the illumination apparatus and the distance between the outgoing radiation end surface and the angle position converting means and the distance between the angle position converting means and the light modulation element are substantially equal.