Stereographic projection system

• US 20030214631A1
• Filed: 03/24/2003
• Published: 11/20/2003
• Est. Priority Date: 12/27/2001
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: InFocus Corporation (Lap-Shun Hui, MBA)
• Inventors: Olsen, Kjell Einar, Andersen, Odd Ragnar, Svardal, Benny Stale
• Granted Patent: US 6,793,341 B2
• Time in Patent Office: Days
• US Class Current: 353/8
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G03B 35/18 by simultaneous viewing
• CPC Class Codes: H04N 13/302 for viewing without the aid of special glasses, i.e. using autostereoscopic displays
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time

Abstract

A projection system configured to project a stereographic image onto a viewing surface is provided, the stereographic image including a left-eye image and a right-eye image. The projection system includes a light source configured to produce a beam of light, a beam splitter configured to split the beam of light into a right image beam and a left image beam, an image engine configured to produce the stereographic image, and a projection lens configured to project the left-eye image and the right-eye image onto the viewing surface. The image engine includes a left optical path configured to produce the left-eye image from the left image beam, the left optical path including an upstream left polarizer, a left image-producing element and a downstream left polarizer, and a right optical path configured to produce the right-eye image from the right image beam, the right optical path including an upstream right polarizer, a right image-producing element and a downstream right polarizer.

Claims

1. A projection system configured to project a stereographic image onto a viewing surface, the stereographic image including a left-eye image and a right-eye image, the projection system including:

a light source configured to produce a beam of light;

a beam splitter configured to split the beam of light into a right image beam and a left image beam;

an image engine configured to produce the stereographic image, the image engine including a left optical path configured to produce the left-eye image from the left image beam, the left optical path including an upstream left polarizer, a left image-producing element and a downstream left polarizer, and a right optical path configured to produce the right-eye image from the right image beam, the right optical path including an upstream right polarizer, a right image-producing element and a downstream right polarizer; and

a projection lens configured to project the left-eye image and the right-eye image onto the viewing surface.

2. The projection system of claim 1, wherein the beam splitter is a polarizing beam splitter and is integral with the upstream left polarizer and the upstream right polarizer.

3. The projection system of claim 2, wherein the left image-producing element is configured to optically rotate selected portions of the left image beam to form the left-eye image, and wherein the right image-producing element is configured to optically rotate selected portions of the right image beam to form the right-eye image.

4. The projection system of claim 3, wherein the polarizing beam splitter is configured to recombine the left image beam and the right image beam optically downstream of the left image-producing element and the right image-producing element.

5. The projection system of claim 1, wherein the downstream left polarizer and the downstream right polarizer are integral.

6. The projection system of claim 1, wherein the upstream left polarizer, the upstream right polarizer, the downstream left polarizer and the downstream right polarizer are integral with the beam splitter.

7. The projection system of claim 1, wherein the left image-producing element is configured to selectively optically rotate portions of the left image beam to form the left-eye image, and wherein the right image-producing element is configured to selectively optically rotate portions of the right image beam to form the right-eye image.

8. The projection system of claim 7, wherein the left image-producing element and right image-producing element are liquid crystal elements.

9. The projection system of claim 8, wherein the liquid crystal elements are liquid crystal on silicon elements.

10. The projection system of claim 1, wherein the left-eye image and the right-eye image are projected simultaneously onto the viewing surface.

11. The projection system of claim 1, wherein the left-eye image and the right-eye image are projected in an alternating manner onto the viewing surface.

12. The projection system of claim 11, further comprising a clean-up polarizer configured to output a polarized beam of light.

13. The projection system of claim 11, further comprising a variable retarder positioned optically between the clean-up polarizer and the beam splitter, the variable retarder being configured to change polarization of the polarized beam of light in an alternating manner.

14. The projection system of claim 13, wherein the beam splitter is configured to direct incident light from the variable retarder along the left optical path and the right optical path in an alternating manner.

15. A desktop projection system configured to project a stereographic image onto a viewing surface, the stereographic image including a left-eye image and a right-eye image configured to be perceived as a single three-dimensional image by a viewer, the projection system comprising:

a body;

a light source disposed within the body, the light source being configured to produce a beam of light;

a beam splitter disposed within the body, the beam splitter being configured to split the beam of light into a left image beam and a right image beam;

a left image-producing disposed within the body, the left image-producing element being configured to produce the left-eye image when illuminated by the left image beam;

a right image-producing element disposed within the body, the right image-producing element being configured to produce the right-eye image when illuminated by the right image beam; and

a projection lens configured to project the left image beam and right image beam onto the viewing surface.

16. The projection system of claim 15, wherein at least one of the left image-producing element and the right image-producing element is a liquid crystal element.

17. The projection system of claim 16, wherein the liquid crystal element is a liquid crystal on silicon element.

18. The projection system of claim 15, wherein the beam splitter is a polarizing beam splitter.

19. The projection system of claim 15, wherein the beam splitter is configured to recombine the left image beam and the right image beam optically downstream of the left image-producing element and right image-producing element, and to direct the left image beam and the right image beam toward the projection lens.

20. A projection system configured to project a stereographic image onto a viewing surface, the stereographic image being configured to be perceived as a single three-dimensional image by a viewer and including a left-eye image and a right-eye image, the projection system comprising:

a light source configured to produce a beam of light;

a projection lens configured to project the stereographic image onto the viewing surface;

a polarizing beam splitter disposed optically between the light source and projection lens, the polarizing beam splitter being configured to split the beam of light into a polarized left image beam and a polarized right image beam;

a left image-producing element disposed optically between the polarizing beam splitter and the projection lens, the left image-producing element being configured to produce the left eye image and to direct the left image beam back toward the polarizing beam splitter; and

a right image-producing element disposed optically between the polarizing beam splitter and the projection lens, the right image-producing element being configured to produce the left-eye image and to direct the right image beam back toward the polarizing beam splitter.

21. The projection system of claim 20, wherein the polarizing beam splitter is configured to recombine the left image beam and right image beam for projection.

22. The projection system of claim 20, wherein the left image beam is directed onto the left image-producing element and the right image beam is directed onto the right image-producing element simultaneously.

23. The projection system of claim 20, wherein the left image beam is directed onto the left image-producing element and the right image beam is directed onto the right image-producing element in an alternating manner.

24. The projection system of claim 23, further comprising a clean-up polarizer configured to output a polarized beam of light.

25. The projection system of claim 24, further comprising a variable retarder optically positioned between the light source and the polarizing beam splitter, wherein the variable retarder is configured to change the polarity of the polarized beam splitter in an alternating manner.

26. A projection system configured to project a stereographic image onto a viewing surface, the stereographic image being configured to be perceived as a single three-dimensional image by a viewer and including a left-eye image and a right-eye image, the projection system comprising:

a light source configured to produce a beam of light;

an image engine configured to produce the left-eye image and the right-eye image in an alternating manner when illuminated by the beam of light;

a polarizer configured to polarize the beam of light, thereby imparting a polarity to the beam of light; and

a variable retarder configured to change the polarity of the beam of light in an alternating manner, the variable retarder having a first state and a second state and configured to be synchronized to the image source to be in the first state when the image source produces the left-eye image and to be in the second state when the image source produces the right-eye image.

27. The projection system of claim 26, wherein the variable retarder is positioned optically upstream of the image source.

28. The projection system of claim 27, wherein the image engine includes a left image-producing element configured to produce the left-eye image, and a right image-producing element configured to produce the right-eye image.

29. The projection system of claim 28, wherein the left image-producing element and the right image-producing element are liquid crystal on silicon elements.

30. The image projection system of claim 28, further comprising a polarizing beam splitter configured to split the beam of light into a left image beam and a right image beam, to direct the left image beam toward the left image-producing element and the right image beam toward the right image-producing element, and to recombine the left image beam and right image beam for projection.

31. The projection system of claim 26, wherein the variable retarder is positioned optically downstream of the image source.

32. The projection system of claim 31, wherein the image engine includes a single image-producing element configured to produce the left-eye image and the right-eye image in an alternating manner.

33. The projection system of claim 32, wherein the image-producing element is a digital micromirror device.

34. The projection system of claim 26, wherein the variable retarder is a liquid crystal shutter.

35. The projection system of claim 26, further comprising a projection lens, wherein the polarizer and the variable retarder are configured to be removably mounted to the projection system downstream of the projection lens.

36. A stereographic adaptor configured to be attachable to a projection system to impart stereographic projection capabilities to a non-stereographic projection system, the projection system including a light source configured to produce a beam of light and an image source configured to produce a left-eye image and a right-eye image in an alternating fashion when illuminated by the beam of light, the stereographic adaptor comprising:

a frame;

a polarizer disposed within the frame, the polarizer being configured to impart a polarity to the beam of light after the beam of light leaves the projection system; and

a variable retarder positioned within the frame optically downstream of the polarizer, the variable retarder being configured to optically rotate the polarity of the beam of light in an alternating fashion, synchronized with the image source.