| 摘要 |
<p>A platy light guide (4) which guides light emitted from an LED (2) and has a light incident end surface (41) for receiving light from the LED (2) and a light outputting surface (43) for outputting a guided light, wherein a plurality of lens rows extending along the directivity direction (X direction) of a light guide incident light in a plane along the light outputting surface (43) and arranged in parallel to each other are formed on the rear surface (44). In the vicinity of the LED (2), the shape of the section perpendicular to their extending directions of the plurality of lens rows is such that the existence proportion of an angle component having an absolute value of at least 20° and up to 50° of an inclination angle formed by a tangent and a lens row forming surface in each fine area is at least 10%. A light polarizer (6) disposed adjacent to the light guide light outputting surface (43) is provided on the light entrance surface (61)thereof with a plurality of lens rows (61a) extending in a direction parallel to the light guide light incident end surface (41) and being parallel to each other. Accordingly, a high-quality surface light source device free from brightness unevenness caused by a fewer LEDs used is provided.</p> |
