| 摘要 |
PROBLEM TO BE SOLVED: To provide a photoelectric sensor capable of executing a detection operation and a diagnostic operation for an object at the same time. SOLUTION: An operation switch includes a plurality of sets of light projection elements 11a, 11b and light receiving elements 12a, 12b, and one-portions of projection lights from the respective sets of light projection elements 11a, 11b are photoreceived by the other sets of light receiving elements 12a, 12b by an optical waveguide. A CPU 21 of the operation switch light-projection-drives sequentially the respective sets of light projection elements 11a, 11b, and detects an object to be detected, based on a detection signal X1 output from a detecting comparator 24, in response to light receiving quantities of the light receiving elements 12a, 12b arranged opposedly to the light-projection-driven light projection elements 11a, 11b, in light projection timings in the respective sets. The CPU 21 further judges a failure, based on a determination signal X2 output from a failure determining comparator 25, in response to light receiving quantities of the other sets of light receiving elements 12a, 12b for receiving the one-portions of the projection lights from the respective sets of light-projection-driven light projection elements 11a, 11b, in the light projection timings in the respective sets. COPYRIGHT: (C)2008,JPO&INPIT
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