| 摘要 |
PROBLEM TO BE SOLVED: To provide a multiple optical axis photoelectric sensor for reducing the time required to accurately discriminate whether the sensor is in a light receiving state or a light shading state to thereby improve a response speed. SOLUTION: A projector 2 of the multiple optical axis photoelectric sensor 1 monitors a synchronizing signal D outputted to a synchronizing signal transmission line 4, judges whether or not the synchronizing signal D is normally transmitted to a light receiving unit 3, generates again the synchronizing signal D corresponding to an optical axis of the same stage and outputs the synchronizing signal D to the synchronizing signal transmission line 4 when recognizing that the synchronizing signal D is not normally transmitted to the light receiving unit 3. Since the synchronizing signal D corresponding to the optical axis of the same stage is immediately and normally transmitted to the light receiving unit 3 just after the projector 2 does not normally transmit the synchronizing signal D to the light receiving unit 3, the light receiving unit 3 can quickly and accurately detect the synchronizing signal D. COPYRIGHT: (C)2004,JPO&NCIPI |
