Patent ID: 7656584

Claim:
A composite lens structure, comprising: a diffusion plate having a first surface; an optical structure formed on the first surface, comprising: a plurality of convex portions arranged in a two dimensional array along a first direction and a second direction, each convex portion comprising a convex low curvature portion and a convex high curvature portion protruding from the convex low curvature portion, the curvature radius of the convex high curvature portion is less than that of the convex low curvature portion; and a plurality of concave portions arranged in a two dimensional array along a first direction and a second direction, each concave portion comprising a concave low curvature portion and a concave high curvature portion depressed from the concave low curvature portion, the curvature radius of the concave high curvature portion is less than that of the concave low curvature portion, wherein each convex portion is adjacent to a plurality of concave portions and each concave portion is adjacent to a plurality of convex portions, and the convex portions, the concave portions and each junction of the convex and concave portions have a curvature different from 0.