PHOTOELECTRIC SWITCH

PURPOSE:To eliminate a dead band of a close distance and to prevent malfunction by providing a photodetection means to a side of an optical path reaching a position detection means and comparing an output of the photodetection means with a close distance output of the position detection means. CONSTITUTION:A photodetection means 3 is provided at a side of an optical path reaching a position detection means 4 from a photodetection optical system 2, and a light that a reflected light from an object X to be detected at a short distance is not collected onto the means 4 via the optical system 2 is detected. A linear position sensing detector(PSD) is used for the means 3 and placed at nearly a right angle to the means 4, and an output IB at a short distance side of the means 4 and an output IC of the means 3 close there to are compared. As a result, when a voltage signal of the output IC is larger than a voltage signal of the output IB, a signal turning immediately on the output circuit is outputted. Thus, even when an object to be detected exists in a dead band of a short distance, it is detected by the means 3 to eliminate almost the dead band, thereby preventing malfunction.