| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect a change in light from a light source other than a lamp. SOLUTION: This lighting system is provided with a lamp 1 for throwing the light to an object surface, a lighting circuit 2 for lighting the lamp 1, two brightness sensors 3A and 3B having mutually different spectral sensitivity characteristics and detecting brightness of the object surface by receiving the reflected light from the object surface and a control part 4 for varying light output of the lamp 1 by controlling the lighting circuit 2 by a dimmer signal corresponding to the light output level of the lamp 1. Since the brightness of the object surface is detected by the brightness sensors 3A and 3B having the mutually different spectral sensitivity characteristics, a change in the light output level of the external light can be detected, and the control part 4 can judge whether or not to be able to determine the corresponding relation of the brightness of the irradiating object surface to the light output level.</p> |
