| 摘要 |
PURPOSE:To eliminate false operation when an object enters an area of detection successively, by eliminating the fluctuation of outputs of two light receiving members for a prescribed time from the delivery of an output of a signal processing circuit which discriminates the sequence of the reception of light by the two light receiving members. CONSTITUTION:A modulated light emitted from a projecting member A and reflected by an object is received by two light receiving members B1 and B2. Then, outputs of change detecting circuits B28 and B18 are processed by a signal processing circuit C, thereby the sequence of reception of light by the light receiving members B1 and B2 is discriminated and thus the direction of movement of the object is detected. When the circuit C delivers an output, a timer circuit E11 is made to act to operate an action display E12, while delivering a signal to canceling circuits F1 and F2 so as to short-circuit, by FET, both ends of amplifier circuits B17 and B27 of the light receiving members B1 and B2 just for a time set by the circuit E11. |
