REFLECTION TYPE PHOTOSENSOR

摘要

PURPOSE:To eliminate the reliability of a detection output without lowering the response, by controlling the scanning of a scanning circuit by an output of a detection circuit so as to increase the detection speed of an object while an output is generated when objects are detected beyond a specified number. CONSTITUTION:A drive pulse from a pulse driving circuit 6 is applied sequentially to light emitting elements 1a-1e by switching operation of a scanning circuit 7 and a light receiving element 2 receives reflected light from an object. Then, a scanning circuit 7 courses a scanning so that either the projection area with the light emitting elements 1a-1e or the light receiving area with the light receiving element 2 or both thereof will be altered in sequence electrically or mechanically. A control circuit 12 controls the scanning of the scanning circuit 7 to increase the detection speed of an object by an output of a comparator 9 of a detection circuit. A decision circuit comprising an integrator 10 and a switch circuit 11 produces an output when the outputs of the detection circuit are detected beyond a specified number. Here, when the element 2 receives reflected light, the scanning of scanning circuit is stopped so that the reception of light will be continued and the decision circuit increases the sampling speed of the output of the detection circuit at the stopping of the scanning.