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:
Jul. 30, 2002
Filed:
Apr. 25, 2001
Ikuo Onishi, Tsukuba, JP;
Katsuya Fujisawa, Tsukuba, JP;
Isao Hamashima, Tsukuba, JP;
Shinji Hiramatsu, Tsukuba, JP;
Yoichi Hashimoto, Hiroshima, JP;
Kuraray Co., Ltd., Kurashiki, JP;
Abstract
A planar light source device includes a light source , a reflector shade , a light guide member having at least one side face positioned adjacent the light source for receiving light from the light source and reflected by the reflector shade, and a light output plate positioned adjacent the light guide member with a first surface positioned adjacent a light exit surface of the light guide member . The first surface is formed with a multiplicity of projections having respective tips held in tight contact with the light exit surface of the light guide member , at least a portion of each of the projections having a curved facet. Of a function descriptive of a sectional shape of each of the projections that is parallel to a direction of travel of light and also a direction normal to the light output plate , the maximum value of the absolute value of a linear differential of a portion representative of a facet counter to the light source is chosen to be within the range of to