| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent unevenness of luminance from occurring in the vicinity of an LED light source caused by light leakage at a stepped part of a light guide without lowering luminance in a surface light source device aimed at thinning. <P>SOLUTION: The light guide has a light guide plate which is thicker on a light incident surface than that on a light emission surface, and has a stepped part gradually reducing the thickness of the light guide between the light incident surface and the light emission surface. On the light guide plate, a lens sheet is arranged so as the light emission surface of the light guide and a lens layer of the lens sheet to be faced with each other. The lens sheet is provided forming a light diffusion layer on the opposite side of the surface with the lens layer formed. The light diffusion layer has 60° glossiness of ≤30%, and a ratio of an internal haze occupying to the total haze to be ≤50%. <P>COPYRIGHT: (C)2011,JPO&INPIT |
