Claims
- 1. A reverse telephoto projection zoom lens, said projection zoom lens having an objective end and an opposite modulator end, said reverse telephoto projection zoom lens comprising:
- a fixed rear lens group at said modulator end of said projection zoom lens for receiving light from said modulator end, said fixed rear lens group having a fixed aperture stop within said fixed rear lens group;
- a moving compensation group for receiving light from said fixed rear lens group; and
- a moving zoom group for receiving light from said moving compensation group.
- 2. The lens of claim 1 having a field of view of at least 23 degrees.
- 3. The lens of claim 1 having a field of view between 23.4 degrees and 33.1 degrees.
- 4. The lens of claim 1 having an object format diameter of at least 1 inch.
- 5. The lens of claim 1 having a throw ratio between 1.47:1 and 2.19:1.
- 6. The lens of claim 1 having a magnification of at least 67X.
- 7. The lens of claim 1 having a magnification between 67X and 100X.
- 8. The lens of claim 1 having a fixed back focal distance of at least 1.34 inches.
- 9. The lens of claim 1 having an effective focal length of at least 0.81 inches.
- 10. The lens of claim 1 having an effective focal length between 0.81 and 1.19 inches.
- 11. The lens of claim 1 having a back focal distance to effective focal length ratio of at least 1.13:1.
- 12. The lens of claim 1 having a back focal distance to effective focal length ratio between 1.13:1 and 1.66:1.
- 13. An image display system for projecting an image, said image display system comprising:
- a light source for generating a beam of light;
- a controller for generating electrical control signals;
- a reflective spatial light modulator for receiving said electrical control signals and for selectively modulating said beam of light in response to said electrical control signals;
- illumination optics for directing said beam of light onto said spatial light modulator; and
- a reverse telephoto projection zoom lens for focusing said selectively modulated beam of light, said reverse telephoto projection zoom lens comprising:
- a fixed rear lens group at said modulator end of said projection zoom lens for receiving light from said modulator end, said fixed rear lens group having a fixed aperture stop within said fixed rear lens group;
- a moving compensation group for receiving light from said fixed rear lens group; and
- a moving zoom group for receiving light from said moving compensation group.
- 14. The image display system of claim 13, said reverse telephoto projection zoom lens having a field of view between 23.4 degrees and 33.1 degrees.
- 15. The image display system of claim 13, said reverse telephoto projection zoom lens having an object format diameter of at least 1 inch.
- 16. The image display system of claim 13, said reverse telephoto projection zoom lens having a throw ratio between 1.47:1 and 2.19:1.
- 17. The image display system of claim 13, said reverse telephoto projection zoom lens having a magnification between 67X and 100.
- 18. The image display system of claim 13, said reverse telephoto projection zoom lens having a fixed back focal distance of at least 1.34 inches.
- 19. The image display system of claim 13, said reverse telephoto projection zoom lens having an effective focal length between 0.81 and 1.19 inches.
- 20. The image display system of claim 13, said reverse telephoto projection zoom lens having a back focal distance to effective focal length ratio between 1.13:1 and 1.66:1.
Parent Case Info
This application claims priority under 35 USC 119(e)(1) of provisional application No. 60/034,976 filed Dec. 31, 1996.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3819256 |
Bellows et al. |
Jun 1974 |
|
5619381 |
Anderson |
Apr 1997 |
|