Patent ID: 7868970
Filing Date: 2011-01-11
Classification: G02B,G02F

Abstract:
1. A transparent light guide plate, comprising: a rectangular light exit surface that constitutes a front portion; and back surfaces that constitute a back portion and which have a shape symmetrical with respect to a symmetry plane that includes a center of said light exit surface and which is perpendicular to one side of said light exit surface, wherein said back surfaces have such a sectional profile that when a section of said light guide plate is taken through a plane that is parallel to said one side and which is perpendicular to said light exit surface and when a point at which an end face of said light guide plate is connected to one of said back surfaces is designated an origin, a position from said origin in a direction parallel to said one side is written as X, and a position from said origin in a direction perpendicular to said one side is written as Y, said sectional shape of each of said back surfaces is expressed by part of a curve that satisfies the following 10