Patent ID: 7391571
Filing Date: 2008-06-24
Classification: G02B,Y10S

Abstract:
1. A diffusion plate used in a direct-type backlight module, comprising: a body having a top surface and a bottom surface, the body having a first refractive index; a plurality of diffusion particles doped in the body for refracting and diffusing the light beams in the body, the diffusion particles having a second refractive index, and the first refractive index being different from the second refractive index; an upper layer attached to the top surface of the body, the upper layer being a transparent material and having a top surface, wherein the upper layer has a second microstructure on the top surface thereof, the second microstructure is constituted by repeated undulation, the upper layer has a fourth refractive index, and the first refractive index is larger than the fourth refractive index; and a lower lever attached to the bottom surface of the body, the lower layer being a transparent material and having a bottom surface, wherein the lower layer has a first microstructure on the bottom surface thereof, and the first microstructure is constituted by repeated undulation, the lower layer has a third refractive index, and the first refractive index is larger than the third refractive index.