DETECTION DEVICE, DOOR DEVICE, AND ELEVATOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a detection device which can detect even a thin string-like object.SOLUTION: A detection device 12 includes: a plurality of light projection elements 16; a light receiving element 21; a calculation section 26; and a determination section 27. The calculation section 26 calculates an index value on the basis of a quantity of light from the plurality of light projection elements 16 received by the light receiving element 21. The determination section 27 determines presence of foreign matters existing in a detection range, on the basis of the index value calculated by the calculation section 26. An optical path radiated from the plurality of light projection elements 16 and received by the light receiving element 21, partly overlaps with a neighboring optical path, when the detection range is observed from the front.