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:
Apr. 14, 1998
Filed:
Apr. 03, 1997
Gang Xu, Northville, MI (US);
John A VanderPloeg, Highland, MI (US);
OIS Optical Imaging Systems, Inc., Northville, MI (US);
Abstract
A normally white twisted nematic liquid crystal display is provided for outputting improved viewing characteristics which are defined by high contrast ratios and reduced inversion. The display includes both positive and negative retardation films, the negative films being defined by n.sub.x =n.sub.y >n.sub.z where the 'z' direction is substantially perpendicular to the film plane and the 'x' and 'y' directions are substantially parallel to the film plane. According to certain embodiments, a pair of positive and a pair of negative retardation films are provided such that the two positive retarders sandwich both the liquid crystal layer and the negative retarders therebetween. By providing the positive and negative retarders with specific retardation values and/or ratios, improved viewing characteristics are provided.