| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an illumination device capable of preventing an unstable action when switching lighting and extinguishing of illumination. <P>SOLUTION: An illumination device 10 includes: light sources 15; a lighting circuit 16; an illuminance detecting portion 21 which detects reflection light of an irradiated surface of the light source 15 and converts that to voltage; and a control portion 35 providing an effective range so as to make a detection value detected by the illuminance detecting portion 21 generally match with a target value corresponding to required brightness, and having an automatic dimming function for outputting adjusting, lighting, and extinguishing signals of optical output. When determining that any one or more of the one or more light sources 15 is in a state immediately before extinguishing, the control portion 35 determines that the detection value is in a generally matching state with the target value and expands the effective range. <P>COPYRIGHT: (C)2013,JPO&INPIT |
