| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light emitting device capable of changing a light emitting area of a light emitting surface as the need arises. <P>SOLUTION: In the light emitting device, light emitted from LEDs 14A close to an incident surface 12a has a short distance for propagating through the air after being emitted from its light emitting surface, and reaches the incident surface 12a almost without having a diffusing action in a longitudinal direction of the incident surface 12a caused by an air layer. Thus, part of the whole light emitting surface 12b of a light guide plate 12 is to emit light as shown in Fig.2(b). Whereas, light emitted from LEDs 14B far from the incident surface 12a has a longer distance for propagating through the air after being emitted from the light emitting surface, and reaches the incident surface 12a by having a large amount of diffusing action in the longitudinal direction of the incident surface 12a caused by the air layer. Consequently, a wider area of the light emitting surface 12b of the light guide plate 12 is to emit light as shown in Fig.2(c). <P>COPYRIGHT: (C)2013,JPO&INPIT |
