摘要 |
A light guide board includes an incidence surface, an emitting surface, and a reflection surface. The incidence surface is frosted and has a roughness-enhanced zone corresponding in location to a light source. The emitting surface forms micro-structures on portions adjacent to the incidence surface and two opposite end surfaces. The portions of the emitting surface forming the micro-structures have magnitude increased roughness as compared to portions that are not provided with micro-structures so that light transmitting through the micro-structures is subject to further diffusion. The reflection surface forms a plurality of prisms extending from the incidence surface with a small (shallow) depth to an opposite surface with a large (deep) depth, with the height of the prisms increasing with the length thereof so that the prism surface of the prisms changes from minimum to maximum, which ensures uniformity of the light emitted from the light guide board.
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