| 摘要 |
<p>An area light source comprises an LED (2), a plate-like lightguide (4) adapted to guide the light emitted from the LED (2) and having a light entering edge face (41) and a light emerging face (43), and an optical polarizing element (6). Continuously arranged on the light emerging face (43) are lens arrays extending generally perpendicularly to the direction of the directivity of the light entering the lightguide (4) from the LED (2) in the plane along the light emerging face (43) and having an average angle of inclination of 0.5° to 60°. On each surface of the lens arrays, a coarse surface having an average angle of inclination of 0.1° to 8° is formed. Continuously arranged on the back (44) of the lightguide are lens arrays extending generally parallel to the direction of the directivity of the light entering the lightguide (4) from the LED (2) in the plane along the light emitting surface (43) and having an average angle of inclination of 8° to 60°. Formed on a light entering surface (61) of the optical polarizing element (6) are prism arrays (61a) parallel to one another and parallel to the light entering edge face (41) of the lightguide. A light reflecting element (8) is so disposed as to be opposed to the back (44) of the lightguide.</p> |
