Ultra-wide angle liquid crystal projector system

• US 5,500,747 A
• Filed: 08/23/1994
• Issued: 03/19/1996
• Est. Priority Date: 08/24/1993
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd., Sega Enterprises LTD.
• Original Assignee: Hitachi, Ltd., Sega Enterprises LTD.
• Inventors: Yoshizaki, Isao, Ogura, Naoyuki, Mori, Shigeru, Muranaka, Masayuki, Wada, Kiyoshi, Tanide, Hideo
• Primary Examiner(s): Gross, Anita Pellman
• Assistant Examiner(s): Abraham, Fetsum
• Application Number:
  US08/294,509
• Time in Patent Office: 574 Days
• Field of Search: 359/40, 359/41, 359/451, 353/79, 353/94, 353/122
• US Class Current: 349/5
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells

Abstract

An ultra-wide angle liquid crystal projector system comprising a light source, a liquid crystal panel, a curved screen, and a projection lens for projecting in accordance with light emitted by the light source an image formed on the liquid crystal panel onto the curved screen. The projection lens has a curvature of field substantially conforming to the shape of the curved screen and an angle of projection of at least 120 degrees. The projection lens is disposed with respect to the curved screen so that a distance from an exit surface of the projection lens to the curved screen is less than 3 meters.

Claims

1. An ultra-wide angle liquid crystal projector system comprising a light source, a liquid crystal panel, a curved screen, and a projection lens for projecting in accordance with light emitted by the light source an image formed on the liquid crystal panel onto the curved screen, the projection lens having a curvature of field substantially conforming to the shape of the curved screen and having an angle of projection of at least 120 degrees, the projection lens being disposed with respect to the curved screen so that a distance along an optical axis from an exit surface of the projection lens to the curved screen is less than 3 meters.

2. An ultra-wide angle liquid crystal projector system according to claim 1, wherein the distance from the exit surface of the projection lens to the curved screen is in the range of 0.3 to 2 meters.

3. An ultra-wide angle liquid crystal projector system according to claim 2, wherein the distance from the exit surface of the projection lens to the curved screen is in the range of 0.6 to 1.5 meters.

4. An ultra-wide angle liquid crystal projector system according to claim 1, wherein the projection lens has a back focal length in the direction of the liquid crystal panel in the range of 0.1 to 2.2 meters.

5. An ultra-wide angle liquid crystal projector system according to claim 4, wherein the back focal length of the projection lens is in the range of 0.2 to 1.2 meters.

6. An ultra-wide angle liquid crystal projector system according to claim 1, wherein the light source and the liquid crystal panel are disposed in a projector body separate from and coupled to the projection lens, at least the projector body being disposed rearwardly of a viewer.

7. An ultra-wide angle liquid crystal projector system according to claim 6, wherein the projector body includes a reflecting mirror for the light source, a condensing lens disposed between the light source and the liquid crystal panel, and a cooling device.

8. An ultra-wide angle liquid crystal projector system according to claim 1, wherein an optical axis of light projected from the projection lens is disposed at an angle greater than 20 degrees with respect to a perpendicular line extending from the center of the screen.

9. An ultra-wide angle liquid crystal projector system according to claim 1, wherein the projection lens is a fish-eye lens.

10. An ultra-wide angle liquid crystal projector system according to claim 1, wherein the curved screen is a dome-like screen.

11. An ultra-wide angle liquid crystal projector system according to claim 10, wherein the curved screen is substantially semispherical.

12. An ultra-wide angle liquid crystal projector system according to claim 1, further comprising additional projection means for projecting additional information onto the curved screen.

13. An ultra-wide angle liquid crystal projector system according to claim 1, wherein the curved screen is provided with at least one dot-like light source thereon, the at least one dot-like light source being selectively energized.

14. An ultra-wide angle liquid crystal projector system comprising a light source, a liquid crystal panel having an image formed thereon, a curved screen and a projection lens for projecting an image formed on the liquid crystal panel by the light source onto the curved screen, the projection lens having a curvature of field substantially conforming to the shape of the curved screen and an angle of projection of at least 120 degrees, the projection lens having a back focal length in the direction of the liquid crystal panel in the range of 0.1 to 2.2 meters, and the projection lens being disposed with respect to the screen so that a distance from an exit surface of the projection lens to the curved screen is less than 3 meters.

15. An ultra-wide angle liquid crystal projector system comprising a light source, a liquid crystal panel having an image formed thereon, a curved screen and a projection lens for projecting an image formed on the liquid crystal panel by the light source onto the curved screen, the projection lens having a curvature of field substantially conforming to the shape of the curved screen and an angle of projection of at least 120 degrees, the projection lens having a back focal length in the direction of the liquid crystal panel in the range of 0.1 to 2.2 meters, and the distance from the exit surface of the projection lens to the curved screen being in a range of 0.3 to 2 meters.