| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a surface illumination device of which brightness is high, and brightness variations are small. <P>SOLUTION: A light-emitting diode 2 as a light source is made so that a transparent resin layer 14 to seal light-emitting elements has a curved surface 14a, of which the center of the curvature is at the light-emitting center of the light-emitting element, and at the curved surface 14a of this transparent resin layer 14, and it is adhered to a recess 10 formed at the side face of the light guide plate 3 with a transparent resin adhesive layer 11, which has the equal refractive index with that of the transparent resin layer 14. Because the light-emitting face is made to be the curved surface 14a, the total reflection of the light emitted from the light-emitting element (and the light which is emitted sideward from the light-emitting element, and reflected back at the reflector) at the light-emitting face is eliminated, and thereby as the light sealed in the light-emitting diode 2 and absorbed is decreased, and light extraction rate from the light-emitting diode 2 can be improved. By this, brightness can be improved, and brightness variations of the surface illumination device 1 caused by the variations of adhering positions and adhesive coating amount can be made smaller by making the influence smaller caused by adhesion grade of the light-emitting diode 2 and the light guide plate 3. <P>COPYRIGHT: (C)2004,JPO |
