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:
Mar. 19, 2002
Filed:
Sep. 22, 1999
Manabu Takata, Tenri, JP;
Takayoshi Tanabe, Tenri, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A surface illuminant device includes a surface illuminant having a light distribution characteristic with no directivity relative to specific directions, and a prism sheet having a plurality of prisms each having a predetermined apical angle. The prism sheet is placed on the light emission side of the surface illuminant. One side of the prism sheet on which a plurality of prisms are placed is opposite to the light emission side of the surface illuminant. Accordingly, light can be emitted in a plurality of specific directions in concentrative manner to enhance luminance in that plurality of directions. Further, the surface illuminant device includes an optical sheet which condenses the incident light. In the luminance distribution (light distribution characteristic) thus obtained, the luminance gently decreases in the vicinity of the directions in which light is emitted in concentrative manner.