| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a surface light source device excellent in productivity capable of enlarging an active area of the light-irradiating face, and irradiating well-regulated white color light with high proportion regardless of the kinds of LEDs arranged as light sources. <P>SOLUTION: Since an indented part 20 formed on a light-incident face 12a of a light guide plate 12 is shaped into a continuous curved surface, light incident on the light guide plate 12 is refracted by the indented part 20, expanded toward a direction along the light-incident face 12a, as well as scattered inside the light guide plate. Further, a light-incident rate of the light entering the light guide plate 12 is prevented from lowering by making a curvature radius R1 of a concave part 20a in the indented part 20 larger than the curvature radius R2 of a convex part 20b. Furthermore, the light entering the light guide plate 12 can be well scattered by providing two or more convex parts 20b of the indented part 20 against a light-irradiating region T of the LED 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
