| 摘要 |
PURPOSE:To speed up the reverse driving of a scanning system, by supplying pulses of higher frequency than the command pulse frequency of a scanning stroke during the reverse driving of the scanning system a specific time after the frequency of command pulses supplied to a motor is set to zero, and then supplying pulses of specific frequency a specific time later. CONSTITUTION:A platen 2 is provided on the top surface of a copying machine casing 1 in a free reciprocating state and driven by the DC motor 8 of a semiconductor driving device 7. The CPU 12 of a computer 11 sends out setting pulses of frequency corresponding to a necessary speed to control the motor 8. The setting pulses for the scanning stroke has a frequency Ns and braking pulses after the completion of scanning has a frequency Nb twice as high as the frequency Ns. The motor 8 is powered off when a return sensor 17 operates in the ending of a return stroke, and pulses of frequency Nb are supplied to the motor 8 by a normal stroke signal time t0 later; and pulses Ns for a scanning stroke are supplied further time t1 later. Consequently, the scanning system is reversed speedily without being applied with large impulsive force. |
