Patent ID: 9541700
Date: 2017-01-10
CPC Classifications: G02B,G02F

Claim:
1. An edge light type back light for use in a liquid crystal display device in which rays of light are dispersed and lead to a front face side, the edge light type back light comprising: a rectangular optical waveguide plate; a lamp disposed along an edge of a longer side of the optical waveguide plate and that emits said rays of light; a light diffusion sheet formed into a rectangular shape, provided with the lamp along an edge of a longer side thereof, and overlaid on a surface of the optical waveguide plate; and a prism sheet overlaid on a surface of the light diffusion sheet; and the light diffusion sheet comprising: wherein the transparent resin is polyethylene terephthalate; wherein a retardation value of the substrate film is greater than 680 nm; wherein the optical layer comprises multiple particles of a light diffusing agent, and a binder therefor; wherein an amount of the light diffusing agent, included per 100 parts of substrate polymer in the polymer composition coating, is 10 parts or greater and 200 parts or less as determined on a basis of solid content; and wherein the multiple particles of the light diffusing agent are spherical beads.