METHOD AND APPARATUS FOR DETECTING MOVING BODY

摘要

PURPOSE:To prevent malfunction due to noises and to make it possible to detect only a specified moving body accurately by inputting infrared rays from the moving body to be detected into a plurality of infrared-ray detectors with time differences by using an optical system. CONSTITUTION:An optical system 1 comprising a Fresnel lens or a reflecting mirror is constituted so as to converge infrared rays from the different areas with respect to two infrared-ray sensors 2a and 2b. Only detected signals in a region corresponding to the average moving speed of a human body and the like are taken out with filters 3a and 3b based on the detected signals 2a and 2b. The effects of temperature gradient and the effect of noises due to a power source are excluded at the same time. In comparators 4a and 4b, the signals through the filters 3a and 3b are compared with a reference voltage. The signals are outputted only when the detected signals are higher than the specified level. A CPU 5 outputs 6 the detected signal of the human body only when two detected signals have the time difference and actuates a crime preventing alarm device and the like. Thus malfunction does not occur by any noise, and only the specified moving body emitting the infrared rays can be detected accurately.