Optical plate having three layers and backlight module with same

摘要

An exemplary optical plate ( 20 ) includes a first transparent layer ( 21 ), a second transparent layer ( 23 ) and a light diffusion layer ( 22 ). The light diffusion layer, the first and second transparent layers are integrally formed, with the first transparent layer and the second transparent layer in immediate contact with the light diffusion layer. The light diffusion layer includes a transparent matrix resin ( 221 ) and a plurality of diffusion particles ( 222 ) dispersed in the transparent matrix resin. The first transparent layer includes a plurality of conical frustum protrusions ( 211 ) at an outer surface thereof that is distalmost from the second transparent layer. The second transparent layer includes a plurality of spherical depressions ( 231 ) at an outer surface thereof that is distalmost from the first transparent layer. A direct type backlight module using the optical plate is also provided.