Research/Patents/US 4997263
US 4997263

AMBIENT LIGHT ILLUMINATED LIQUID CRYSTAL DISPLAY SYSTEM

Assignee

ALLIED-SIGNAL INC.

Filed

Jun 12, 1989

Granted

Mar 5, 1991

Location

MATAWAN NJ US

Abstract

A liquid crystal display system utilizes an optical arrangement which is aligned so that ambient light from the direction of an obersver's view is channeled behind the liquid crystal display to provide back illumination therefor. An illuminator is arranged to provide supplementary illumination for the liquid crystal display as may be required. A photodetector determines when ambient light is inadequate for required display brightness and operates through appropriate control circuitry to turn the illuminator on or off as the case may be and to control the contrast of the liquid crystal display.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Sep 28, 1989

Rescinded

Sep 20, 1990

Duration

11 months

Inventor

  • 1RICHARD L. COHEN

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Back to patent indexSource: USPTO 35 USC §181 secrecy order records