Around being detected around being detected

摘要

PROBLEM TO BE SOLVED: To prevent a person from feeling dazzled by allowing the eyes of the person to easily adapt themselves by detecting the presence of a person based on the change of thermal amounts made incident from a detection area to a thermal sensor, turning on an illuminating load with a low light output, and gradually increasing a light output until a prescribed value according to the lapse of time. ;SOLUTION: The output of a pyroelectric infrared sensor (pyroelectric sensor) 1 as a thermal sensor for detecting a heat wave from a human body is amplified, and a microcomputer 2 A/D converts the output of the amplifying part 11, and generates a detection signal at the time of judging that a person is present in a detection area based on the output of the pyroelectric sensor 1. Also, surrounding brightness detected by a brightness sensor 3 is compared with a light-off value and a light-on value set by an operating illuminance adjusting part 4 for stepwisely or continuously adjusting a light-off value and a light-on value. Then, when the presence of a person is detected, an illuminating load is turned on with a low light output, and the light output is gradually increased to a prescribed value according to the lapse of time.;COPYRIGHT: (C)1998,JPO