| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light guide plate and illuminating device suitably used for a liquid crystal display device, capable of saving power by illuminating only a predetermined region of a panel with information displayed. <P>SOLUTION: The light guide plate 10 is formed so that a thickness of the light guide plate 10 reduces as getting away toward both ends from a boundary. Light L2 incident from a light entering end surface to the light guide plate repeats total reflection by reflecting in a direction for reducing an angle for entering on a reflecting surface S1 in a region of the light guide plate until passing the boundary, and the light is not emitted from a light emitting surface 10C to an external. On the other hand, the light repeats reflection in a direction for increasing an angle for entering on a reflecting surface S2 in a region of the light guide plate after passing the boundary, and the light is emitted beyond a critical angle to the light emitting surface. Therefore, a part of the region of the light guide plate can be illuminated by lighting only a light source at one end, and only the predetermined region of the liquid crystal panel can be illuminated, resulting in power saving. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
