| 摘要 |
PROBLEM TO BE SOLVED: To obtain a desired luminance distribution by forming a light diffusion part in cyclic uneven structure and providing a flat part and at least >=2 projection parts in one cycle. SOLUTION: A light source 1 represented by a cold-cathode-ray tube is provided on the side of the light incidence surface 2 of a light guide body 3. A liquid crystal 5 and a light diffusion plate are provided at a light emitting surface 4 side of the light guide body 3. The light emitted by the light source 1 travels in the light guide 3 and exits from a light projection surface 4, so that this light is observed by an observer. Here, one tube or two tubes may be used as the light source 1. Further, a perpendicular type light source is usable. On the surface of the light diffusion plate 6, a cyclic ruggedness group is formed and >=2 projection parts and a flat part are provided in one cycle of the ruggedness group. In this case, the luminance distribution of projection light is formed by putting luminance distributions obtained by respective pattern one over another. Therefore, an arbitrary luminance distribution can be obtained. |
