Patent ID: 7623293

Claim:
An optical element for receiving an incident light, comprising: a first optical surface; a second optical surface; a first transparent diffusion unit located on the first optical surface, for diffusing the incident light, wherein the first transparent diffusion unit comprises a first semi-lenticular len with a first height; a first transparent collimation unit located on the first optical surface and adjacent to the first transparent diffusion unit, for collimating the incident light, wherein the first transparent collimation unit comprises a first prism with a second height, a second transparent diffusion unit located on the first optical surface and adjacent to the first transparent collimation unit, for diffusing the incident light, wherein the second transparent diffusion unit comprises a second semi-lenticular len with the first height; a second transparent collimation unit located on the first optical surface and adjacent to the second transparent diffusion unit, for collimating the incident light, wherein the second transparent collimation unit comprises a second prism with the second height; wherein the second optical surface is a smooth surface and the first height equals to the second height.