| 摘要 |
PURPOSE:To exercise speed control extremely easily through magnetic coupling so as to obtain a stable stopping position, by controlling the moving speed of an original by using a hysteresis clutch in accordance with the moving position of the original. CONSTITUTION:A clock pulse corresponding to the moving distance of an original is generated by means of an encoder 15-2 fitted to a DC motor. Moreover, when a flag plate 15-7 installed to a mirror table traverses fixed sensors, signals are outputted. One of the sensors is one 15-5 for detecting the home position of an optical system and the other is a sensor 15-6 for detecting the first end of a picture. When the original is advanced, a speed corresponding to the magnification is controlled by a slave CPU and, at the time of backward movement, the backward movement is turned off by means of the sense signal of the sensor 15-6 and braking control is performed in the extent of a prescribed position by using a hysteresis clutch. |
