| 摘要 |
PROBLEM TO BE SOLVED: To obtain a plane lighting system capable of providing uniform light every nook and corner of a light guide plate. SOLUTION: A prism surface 6 having larger inclined angles toward both side parts from the center of a light guide plate 2 is formed in the backside 4 of the light guide plate 2, a slope 5 is formed to the position opposing to the prism surface 6 on the surface 3, light from a light source 10 is dispersed even in both side directions at first, and the light is reflected in the side direction distant from the light source 10 or in the optional direction of the thickness of the light guide plate 2. |
