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. 15, 2000
Filed:
Nov. 07, 1997
Tsuyoshi Ishikawa, Tokyo, JP;
Hiromi Sasako, Tokyo, JP;
Enplas Corporation, Kawaguchi, JP;
Yasuhiro Koike, Yokohama, JP;
Abstract
In a surface light source device of side light type applied to a liquid crystal display device, etc., more specifically a surface light source device of side light type having a directivity emitting characteristic, a bright-and-dark-band contrast which is generated in a vicinity of an incidence surface is prevented. In a surface light source device of side light type, light diffusible areas composed on main-and-supplementary diffusible areas are formed on a slanted surface and an emitting surface of a light guide plate having a directivity emitting characteristic. A silver sheet is fixed to a projected portion of a prism sheet along an upper edge, and an illumination light which arrives at the upper edge from a fluorescent lamp is blocked so that the strong brightening of the upper edge is prevented. An illumination light form a lower edge is blocked by a reflector or a frame and reflected diffusively. The light diffusible area may be formed on one of the slanted surface and the emitting surface. Moreover, the light diffusible area may be formed on an additional element such as a reflection sheet.