The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 10, 1982
Filed:
Dec. 14, 1979
William P Bleha, Jr, Carlsbad, CA (US);
Hughes Aircraft Company, Culver City, CA (US);
Abstract
Method of and apparatus for operating an electro-optical system for producing high quality images from a liquid crystal light valve. A polarized projection beam is directed to the reflective surface of a liquid crystal light valve for polarization modulation by means of an input image. The beam is polarization analyzed to thereby generate an output image which typically suffers from color and brightness defects caused by economically unavoidable tolerance variations in the electro-optical system. A second beam of light is generated having a light of a selected color different from the projection beam, is spatially varied in intensity by a spatially graded filter, and super-imposed on the output image so as to eliminate the color and brightness defects as well as enhance color contrast and brightness of the image. The color of the second beam is selected so as to mask background color variations and improve color contrast on the output image while the graded intensity filter is selected to additively compensate for background brightness variation of the output image.