Patent ID: 7806546

Claim:
An optical plate, comprising: a first transparent layer; a second transparent layer; and a light diffusion layer between the first transparent layer and the second transparent layer, the light diffusion layer including a transparent matrix resin and a plurality of diffusion particles dispersed in the transparent matrix resin; wherein the first transparent layer, the light diffusion layer, and the second transparent layer are integrally formed, with the first transparent layer in immediate contact with the light diffusion layer, and the second transparent layer in immediate contact with the light diffusion layer, the first transparent layer defines a plurality of first conical frustum-shaped depressions at an outer surface that is farthest from the light diffusion layer, the second transparent layer defines a plurality of second conical frustum-shaped depressions at an outer surface that is farthest from the light diffusion layer, and the interface between the light diffusion layer and the first transparent layer defines a plurality of micro-recesses having a same shape and arrangement as the plurality of second conical frustum-shaped depressions at the outer surface of the second transparent layer.