Patent ID: 7448776
Filing Date: 2008-11-11
Classification: G02B

Abstract:
1. A brightness enhancement film having curved prism units, said brightness enhancement film being arranged to be used in a liquid crystal display, comprising: a substrate including a first surface and a second surface substantially parallel to said first surface, and vertically transmitting light between the first surface and the second surface; and a plurality of curved prism units juxtaposed on the first surface of the substrate, each of the curved prism units having a longitudinal direction and including a ridge, a first meandering surface, and a second meandering surface, said first and second meandering surfaces jointly define the ridge and a trough line being defined between any two adjacent curved prism units as a boundary of the adjacent units, said ridge and said meandering surfaces extending and meandering with respect to the longitudinal direction to provide changes in curvature that are able to refract light in two dimensions, wherein directions of said ridge and said meandering surfaces relative to said longitudinal direction vary along a length of each of said prism units, wherein each of the first meandering surface and the second meandering surface includes a plurality of lateral ridges arranged in staggered manner in the longitudinal direction to provide changes in curvature, with a curvature of each lateral ridge adjacent to either of the ridge or the trough line being smaller than a curvature of each lateral ridge beyond both of the ridge and the trough line.