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:
Nov. 09, 2004
Filed:
Dec. 01, 1999
Kazumasa Ohsumi, Hatogaya, JP;
Enplas Corporation, Kawaguchi, JP;
Abstract
A liquid crystal display includes a surface light source device of a side light type for lighting. On lighting a fluorescent lamp, primary light is introduced into a guide plate and propagates within the guide plate. Much of the illumination light enters into any one of a number of ridges on an emission-function face, being followed by inner impingement upon a flank face, which is more remote from an incidence end face, at an entry angle greater than a critical angle &thgr; 1. Much of the light which has undergone such inner impingement is supplied to a liquid crystal display panel almost frontward via a top face. The ridges are inclined at a predetermined inclination angle &agr; with respect to the incidence end face of the guide plate. Inclination angle &agr; preferably falls within a range from 5 degrees to 45 degrees, in particular, from 15 degrees to 30 degrees. Employment of size-reduced ridges is realizable, leading to less conspicuous ridges without reducing emission function. Moire fringes are preventable, too. Each ridge may be provided with all or some of a tapered shape, an inclined flank face and foot portions with a stepwise difference.