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:
Jan. 07, 2003
Filed:
Mar. 30, 2001
Mitsubishi Rayon Co., Ltd., Tokyo, JP;
Abstract
A planar light source device contains a light source ( ); a light guide ( ) which has a light incident face ( ) on at least one side end surface thereof which confronts the light source ( ), and a light emitting face ( ) on one of two principal surfaces ( ) thereof; and a light direction varying sheet ( ) which is disposed on the light emitting face ( ) of the light guide ( ), wherein a back surface ( ) of the light guide ( ) opposing to the light emitting face ( ) is formed as a prism surface which comprises a plurality of elongated prisms each having substantially triangular cross section of a vertical angle within a range of 60 to 80° or 125 to 150° so as to extend in parallel to each other and in perpendicular to the light incident face ( ), and a major part of the light emitting face ( ) is formed as an uneven surface having an average slant angle of 0.3 to 30°.