DISTANCE MEASURING PHOTOELECTRIC SENSOR AND OBJECT DISTANCE MEASURING METHOD

PROBLEM TO BE SOLVED: To provide an improved distance measuring method that uses a pulse average method.SOLUTION: A distance measuring photoelectric sensor (10) for a distance measurement of an object in a monitoring area (20) is proposed that comprises: a light projector (12) for projecting a projection light beam (16); a light receiver (26) for generating a light reception signal from the projection light beam (22) subjected to a diffuse reflection by the object in the monitoring area (20) or reflected thereby; an AD converter (34) for sampling the light reception signal; and an evaluation section (32). The projection light beam (16) has many projection light pulses which are mutually continuous, and the evaluation section (32) adds many light reception pulses to be generated from the projection light pulse and in the sampled light reception signal in a sum signal, determines a light reception time from the sum signal, and thereby measures an object distance, using a method for measuring propagation time of light. The evaluation section (32) is provided with a digital filter for filtering the sum signal to determine the light reception time, and the digital filter is an optimum filter suitable for the light reception pulse.