Stereographic projection system

• US 6,547,396 B1
• Filed: 12/27/2001
• Issued: 04/15/2003
• Est. Priority Date: 12/27/2001
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: InFocus Corporation (Lap-Shun Hui, MBA)
• Inventors: Andersen, Odd Ragnar, Svardal, Benny Stale, Olsen, Kjell Einar
• Primary Examiner(s): Adams, Russell
• Assistant Examiner(s): Koval, Melissa J
• Application Number:
  US10/040,869
• Time in Patent Office: 474 Days
• Field of Search: 353/7, 353/8, 353/10, 353/20, 353/31, 353/34, 353/37, 353/82, 353/84, 353/98, 353/99, 353/102, 359/462, 359/464, 348/42, 348/51, 348/54, 348/55, 348/57, 348/58
• 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 for projecting 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 for producing a beam, a beam splitter for splitting the beam of light into a right image beam and a left image beam, an image engine for producing the stereographic image, and a projection lens. The image engine includes a left optical path for producing 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 polarizing beam splitter configured to split the beam of light into a right image beam and a left image beam of different polarities;

an image engine configured to produce the stereographic image, the image engine including 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, wherein the polarizing beam splitter is configured to direct the left image beam toward the left image-producing element and the right image beam toward the right image-producing element, and wherein the polarizing beam splitter is configured to recombine the left image beam and the right image beam after the production of the left-eye image and right-eye image; 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 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.

3. The projection system of claim 2, wherein the polarizing beam splitter is configured to direct the left image beam and right image beam toward the projection lens after recombining the left image beam and the right image beam.

4. 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.

5. The projection system of claim 4, wherein the left image-producing element and right image-producing element are liquid crystal elements.

6. The projection system of claim 5, wherein the liquid crystal elements are liquid crystal on silicon elements.

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

8. 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.

9. The projection system of claim 8, further comprising a clean-up polarizer positioned optically upstream of the polarizing beam splitter, wherein the clean-up polarizer is configured to output a polarized beam of light.

10. The projection system of claim 9, 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.

11. The projection system of claim 10, 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.

12. 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 element disposed within the body, the left image-producing element being configured to produce the left-eye image when illuminated by the left image beam and to reflect the left image beam back toward the beam splitter;

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 to reflect the right image beam back toward the beam splitter; and

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

13. The projection system of claim 12, wherein the liquid crystal element is a liquid crystal on silicon element.

14. The projection system of claim 12, wherein the beam splitter is a polarizing beam splitter.

15. The projection system of claim 12, 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.

16. 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.

17. The projection system of claim 16, wherein the polarizing beam splitter is configured to recombine the left image beam and right image beam for projection.

18. The projection system of claim 16, 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.

19. The projection system of claim 16, 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.

20. The projection system of claim 19, further comprising a clean-up polarizer configured to output a polarized beam of light.

21. The projection system of claim 20, 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.

22. 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.

23. The projection system of claim 22, wherein the variable retarder is positioned optically upstream of the image source.

24. The projection system of claim 23, 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.

25. The projection system of claim 24, wherein the left image-producing element and the right image-producing element are liquid crystal on silicon elements.

26. The image projection system of claim 24, further comprising a polarizing beam splitter positioned optically downstream of the variable retarder, wherein the polarizing beam splitter is 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, to recombine the left image beam and right image beam, and to direct the recombined left image beam and right image beam toward the projection lens.

27. The projection system of claim 22, wherein the variable retarder is positioned optically downstream of the image source.

28. The projection system of claim 27, 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.

29. The projection system of claim 28, wherein the image-producing element is a digital micromirror device.

30. The projection system of claim 22, wherein the variable retarder is a liquid crystal shutter.

31. The projection system of claim 22, 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.

32. 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 from the entire beam of light 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.