Patent ID: 7530725
Filing Date: 2009-05-12
Classification: G02B

Abstract:
1. A backlight module comprising: a light guide plate comprising: a plurality of side surfaces including two main side surfaces adjoining to each other; an incident surface disposed at one main side surface; an emitting surface disposed at the other main side surface; a bottom surface opposite to the emitting surface; and a plurality of depressions formed on the emitting surface, each depression having a refractive surface and a reflective surface adjoining the refractive surface, wherein the reflective surface faces the incident surface, and the refractive surface faces away from the incident surface, an acute angle defined by the emitting surface with respect to the refractive surface is larger than an acute angle defined by the emitting surface with respect to the reflective surface; a light source disposed adjacent to the incident surface; and a prism sheet having a prism surface facing the emitting surface, the prism surface having a plurality of prisms protruding out from the prism surface, each prism being a shape of triangular projection having a vertex angle facing the prism surface, the vertex angle being slanting away from the incident surface.