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. 16, 1994
Filed:
Oct. 01, 1992
Charles A Rudisill, Apex, NC (US);
Daniel J Whittle, Apex, NC (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
A transflective liquid crystal display (LCD) uses the reflective and refractive characteristics of an edge-lit flat light pipe as a backlight panel behind the liquid crystal layer. The front and/or back surfaces of the edge-lit backlight panel are textured to enhance reflectivity of ambient light and transmission of edge light. The front surface of the panel is textured with pits that have walls at an angle to enhance reflectivity over a range of viewing angles. Further, the back surface of the panel is textured with pits having wall angles, and a pattern to enhance the uniform reflection of edge light toward and through the front surface of the backlight panel. The indentations may be conical, triangular or random. The pit wall angles lie within a preferred range of angles to optimize the amount of light within the useable viewing angle for the LCD. Alternative embodiments include backlight panel where only the front surface has indentations and the back surface is flat and mirrored, or where only the back surface of the panel has indentations and the front surface is flat.