| 摘要 |
<p>An illumination device includes a light source composed of a light emitting element (15) and an intermediate light guide (13), and a light guide plate (12) that receives light from the light source through a light incident face (12a) and that emits the light propagating therein from an emergent surface. A reflecting surface of the light guide plate has a plurality of prism grooves (14) formed in stripes in plan view, each prism groove having a gently inclined face (14a) and a sharply inclined face (14b) inclined more sharply than the gently inclined face. A &thetas;2-coefficient, which is the product of the number of the sharply inclined faces per unit length of the light guide plate, and the length (L) of the sharply inclined faces, is increased away from the light source in the light guide plate. <IMAGE></p> |
