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:
May. 11, 2004
Filed:
Feb. 04, 2003
Takuro Sugiura, Fukushima-ken, JP;
Ohizumi Mitsuo, Fukushima-ken, JP;
Tatsumaro Yamashita, Fukushima-ken, JP;
Alps Electric Co., Ltd., Tokyo, JP;
Abstract
One major surface of a light guide plate is formed, in stripe form in a plan view, with a plurality of prism grooves each consisting of a slight slope and a steep slope. The inclination angles of the slight slope and the steep slope are in ranges of 1° to 10° and 41° to 45°, respectively. The width of the steep slope in the one major surface of the light guide plate increases as the position increases from a light incident surface of the light guide plate such that a ratio of the width of the steep slope at a position farthest from the light incident surface to the width of the steep slope at a position closest to the light incident surface is 1.1 to 1.5.