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:
Nov. 10, 1992
Filed:
Feb. 25, 1992
Masao Obata, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
With the aim of mitigating a decrease in flux of light and improving the light utilization efficiency, an optical conductor used in a liquid crystal lighting apparatus is constructed of a plurality of refractive layers N.sub.1, N.sub.2, . . . , N.sub.i of different refractive indices which are gradually lowered from light incident end surfaces to a center portion of the optical conductor. Light coming from the light incident end surfaces is refracted at interfaces of the refractive layers N.sub.1, N.sub.2, . . . , N.sub.i so as to reach a light outgoing surface at an incident angle .theta..sub.i which is smaller than a critical angle .theta..sub.w, thereby preventing all the beams from undergoing total reflection at the light outgoing surface and shortening the optical length in the optical conductor.