Eugene W Cross

US Patent:

53030834, Apr 12, 1994

Filed:

Aug 26, 1992

Appl. No.:

7/935622

Inventors:

Randall D. Blanchard - Vista CA
Eugene W. Cross - Escondido CA
Ronald D. Shirley - Vista CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G02B 532
G02B 2728
G02F 11335

US Classification:

359495

Abstract:

Liquid crystal light valve projection systems can use substantially all of the reading light from a high intensity reading light source by converting all single polarization state. Light reflected from a polarization beam splitter (44) that cannot be used because it is of wrong polarization state is recovered with improved efficiency, color balance and collimation by means of a polarization recovery prism (50) employing a reflective surface (56) interposed between two quarter-wave retarders (58,60). The light of wrong polarization from the polarizing beam splitter (44) is passed through a first quarter-wave retarder (58), which circularly polarizes the beam. The beam is then reflected from a mirrored surface (56) to reverse the direction of the circular polarization. The reflected beam of reversed circular polarization is then converted to a beam of light of the desired polarization by passage through a second quarter-wave retarder (60) and is transmitted in a path parallel to the path of the original beam together with light transmitted directly from the polarization beam splitter (44).

US Patent:

49431552, Jul 24, 1990

Filed:

Oct 11, 1989

Appl. No.:

7/419985

Inventors:

Eugene W. Cross - Escondido CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G03B 2100
G02B 504
G02F 113

US Classification:

353 33

Abstract:

An embedded polarizing beamsplitter employed in a liquid crystal light valve color projector introduces lateral chromatic aberration of complex distribution that degrades contrast and resolution of the projected image. Color correction is provided to substantially eliminate any noticeable lateral chromatic aberration by replacing the output window of the prism with an optical wedge made of the same material as the embedded prism plate of the beamsplitter.

US Patent:

48909017, Jan 2, 1990

Filed:

Dec 22, 1987

Appl. No.:

7/137486

Inventors:

Eugene W. Cross - Escondido CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G02B 504
G02B 718
G02F 113

US Classification:

350168

Abstract:

An embedded polarizing beamsplitter employed in a liquid crystal light valve color projector introduces lateral chromatic aberration of complex distribution that degrades contrast and resolution of the projected image. Color correction is provided to substantially eliminate any noticeable lateral chromatic aberration by replacing the output window of the prism with an optical wedge made of the same material as the embedded prism plate of the beamsplitter.