| 摘要 |
PURPOSE:To cover a wide range, by photodetecting a light beam which has been projected from one projecting element and has been reflected by an object to be detected, by photodetector group, and comparing a peak value of each output with a threshold value decided in advance. CONSTITUTION:A light beam 2 emitted from a projecting element 1 is converted to a parallel light beam 4 by an optical system 3 and is irradiated to an object to be detected 5. It is irregularly reflected by the surface of the object to be detected 5, its reflected ray is focused by an optical system 9, and is led to a photodetector group 10. An output of the photodetector group 10 is sent to a peak value detecting circuit 11, a peak value is detected, its peak value is compared with a threshold value decided in advance by a discriminating circuit 12, and a signal showing ''exist'' of a detected object is outputted. |
