| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that when an LED illumination device used for a signboard is used for a large-sized signboard, a light flux of the LED illumination device is insufficient compared to that of an illumination device using a metal halide lamp, sufficient illuminance cannot be obtained to the lower portion of the signboard, the capacity of an LED light source needs to be increased in order to obtain uniform illuminance to the lower portion of the signboard, and as a result, a light source portion has a large size and a heavy weight. <P>SOLUTION: In the external LED-illuminated signboard, a high power LED illumination fixture which is used for a large-sized illuminated signboard and has comparatively reduced weight is provided in the upper portion of the signboard, a low power LED illumination fixture is provided in the lower portion of the signboard, and the surface of the signboard is made to have a uniform luminance by setting a power ratio of the LED illumination fixture in the upper portion and the lower portion of the signboard to 3 times or more. <P>COPYRIGHT: (C)2012,JPO&INPIT |
