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:
Feb. 02, 1999
Filed:
Dec. 12, 1996
Gregory P Crawford, Providence, RI (US);
Thomas G Fiske, Campbell, CA (US);
Louis D Silverstein, Scottsdale, AZ (US);
Xerox Corporation, Stamford, CT (US);
Abstract
A transmissive, backlit color twisted-nematic or super-twisted-nematic liquid crystal display employing a front fiber-optic faceplate or optical equivalent as a front retaining element of a liquid crystal cell that increases viewing angle between the display and a viewer while minimizing or eliminating undesirable variations in luminance, contrast ratio and chromaticity is described. The fiber-optic faceplate or optical equivalent includes cylindrical optical features and interstitial cladding material of greater optical index than the cylindrical optical features. The interstitial cladding material may include an opaque mask blocking layer to prevent the interstitial apertures from diffracting off-axis light into an observer's viewing cone. In particular the liquid crystal display includes dual negative retarders, and a light shaping element such as a brightness enhancing film on the illumination source that increase the effective viewing angle between the display and a viewer while minimizing undesirable variations in display chromaticity, luminance, and contrast ratio. The front fiber-optic faceplate or optical equivalent works in conjunction with the dual negative retarders and the light shaping element to provide an improved contrast ratio with a perfectly symmetric viewing angle and to eliminate grey scale inversions.