(12) United States Patent
(io) Patent No.: (45) Date of Patent:
US 7,101,048 B2 Sep. 5, 2006
(54) FLAT-PANEL PROJECTION DISPLAY
(75) Inventor: Adrian Robert Leigh Travis, South Devon (GB)
(73) Assignee: Cambridge Flat Protection Displays Limited, (GB)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 47 days.
(21) Appl. No.: 10/490,246
(22) PCT Filed: Sep. 25, 2001
(86) PCT No.: PCT/GB01/04269
§ 371 (c)(1),
(2), (4) Date: Mar. 19, 2004
(87) PCT Pub. No.: WO03/027754 PCT Pub. Date: Apr. 3, 2003
(65) Prior Publication Data
US 2004/0246391 Al Dec. 9, 2004
(56) References Cited
U.S. PATENT DOCUMENTS
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FOREIGN PATENT DOCUMENTS
DE 19636459 A 3/1998
Amitai, Y., "Visor-display design based on planar holographic optics," Applied Optics, Mar. 10, 1995, pp. 1352-1356, vol. 34, No. 8, Optical Society of America.
Primary Examiner—Melissa Jan Koval
(74) Attorney, Agent, or Firm—Young & Basile, PC.
A flat-panel projection display comprises a slab waveguide having a preferably embossed diffraction grating on one face, a lens for directing light into an edge of the waveguide, and in the focal plane of the lens a liquid-crystal modulator for modulating the intensity of the light as a function of lateral position and elevational direction of travel. The light is ejected from the slab waveguide by the grating at angles corresponding to the input angles, giving a virtual display. The light from the modulator can be expanded in one dimension by passing through a magnifying waveguide, followed by scattering in the plane by a screen and projection by a lens at the other end of the waveguide. Head-up and 3-D displays can be constructed using this principle.
24 Claims, 8 Drawing Sheets