BRIGHTNESS SENSOR AND ILLUMINATING DEVICE WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To simplify a circuit constitution more than a conventional one as suppressing errors in detecting brightness in the case of the presence of an object different in reflectance from environment. SOLUTION: Light receiving elements S1-S4 individually receive reflected light from detecting areas A1-A4 set in a plane to be detected, which is an object of brightness detection, and increase current output according to increases in the quantity of received light. The light receiving elements A1-A4 are serially connected, and both ends of the series circuit of the light receiving elements A1-A4 are passed through an amplifier 10 to be the outputs of a brightness sensor 20.