| 摘要 |
PURPOSE:To make the whole of a titled device small-sized, by using it in common as one optical means for light emission and photodetection, installing a light emitting element and a photodetector within a vicinal range of a focus of said one optical means, and combining the spaces required for light emission and photodetection. CONSTITUTION:A convex lens 11 functioning as an optical means which stops down emitted laser light to a suitable divergence angle and also condenses the reflected light reflected from an object, a laser diode 12 functioning as a light emitting element, and a photodetector 13 are provided on a light emittng and photodetecting part 100. An insulator 14 insulates the photodetector 13. A light emitting circuit 15 drives the laser diode 12. A photodetecting circuit 16 amplifies a signal of the photodetector. A display alarm circuit 300 and a signal processing and operating part 200 are connected to a connector 18 for transmitting and receiving a timing signal to the light emitting circuit 15, an output signal from the photodetecting circuit 16, and an electric power supply. |
