Diffusion plate and backlight module using the same

Abstract

A diffusion plate (20) includes a substrate (26) and a diffusion layer (22) disposed at a surface of the substrate. The substrate defines a plurality of through holes (28). A portion of light beams from an associated light source is reflected and refracted at walls of the substrate surrounding the through holes, and subsequently is diffused by the diffusion layer to display images. Another portion of the light beams propagates directly to the diffusion layer via the through holes, thereby avoiding partial absorption within the substrate. Thus the overall utilization of light beams is increased. A backlight module includes, for example, a light guide plate having a light incident surface and a light emitting surface, a light source disposed adjacent to the light incident surface, and the above-described diffusion plate disposed adjacent to the light emitting surface.

Dependencies are inferred from the claim text.