| 摘要 |
Disclosed is a surface light source having high luminance and optimum luminance distribution, which comprises a light guide plate having a light-emitting surface and one or more light incident surfaces, a light source supplying light to the light incident surfaces, a light diffusion layer formed on the rear surface of the light-emitting surface of the light guide plate, and a reflector plate arranged on the rear surface side. The light diffusion layer is so dispersed that the ratio of the unit area of the rear surface occupied by the light diffusion layer increases as it recedes from the light source. The light diffusion layer has a 10-point average surface roughness of 8-25 μm, and the average distance between recesses and projections of the surface of the light diffusion layer is 20-150 μm. |
