Patent · US Expired

Liquid crystal image projector system

US4195915A · kind A · utility

81Cited by
1References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 5, 1978
Grant dateApr 1, 1980
Priority date
Expiry dateMay 5, 1998

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F1/13439
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

There is disclosed a liquid crystal image projector which is suitable for use as an image source in an aircraft head-up display system. In this application, the projector provides extremely bright and high contrast symbology for the aircraft pilot. More generally, the projector has application wherever a television-type raster and/or calligraphic symbology display is needed. The increase in brightness and contrast ratio is achieved by using a reflector to concentrate light from a light source onto the liquid crystal display cell from whence it is reflected through an optical aperture stop in the reflector to the projecting lens and thence to a viewing surface.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.