| 摘要 |
PURPOSE:To stably operate independently of surrounding noise, by performing the stop position control for a reflecting mirror rotating motor using a photosensor, in an optical switch which selects propagated light from a plurality of optical fibers and makes the light incident to a specified optical fiber. CONSTITUTION:A reflecting mirror fixture 14 to fit a reflecting mirror 9 to a rotating shaft 13 of a motor is provided with a projection 15, and the end surface of the projection 15 is taken as a mirror surface end 16. Reflection type photosensors 17 are disposed opposing to the mirror surface end 16 with an angle of 60 deg. respectively. Each sensor 17 is incorporated with a light emitting diode 18 and a phototransistor 19 for photodetection. When the motor rotates and the end 16 opposes to an arbitrary sensor 17, a light of the diode 18 is reflected at the end 16 to turn on the transistor 19. When a rotary switch 21 is selected and an arbitrary one of the diodes 18 is selected and a prescribed voltage is given to the diode, the selected diode 18 illuminates, and when the reflection end surface 16 in synchronizing rotation with a driving pulse of a pulse generator 20 opposes to said diode 18, the transistor 18 turns on and the motor is stopped. |
