| 摘要 |
PURPOSE:To prevent an uneven image by providing a means for setting a time constant of a servo-motor driving system, and a means for driving a servo-motor by said means. CONSTITUTION:When a variable power key 20 is operated, and for instance, a reduction mode is selected, time constant data is inputted to a speed counter 22b from a time constant setting circuit 21, a frequency from a reference frequency generating circuit 22a is divided, and a pulse signal whose pulse width is narrow is outputted to a START circuit 22c. Also, from the key 20, a START signal is inputted to the circuit 22c and a driver circuit 22g, and an F/R signal is inputted to the circuit 22g. As a result, a servo-motor 2 is driven to rotate in the forward direction, and a signal from an encoder 23 is inputted to the circuit 22c. On the other hand, when the START signal is inputted to the circuit 22c, from a phase comparator 22d through terminals S, Ep, in case when an encoder signal leads a reference signal, and in case when the former signal lags the latter signal, a pulse having a pulse width of a phase difference is generated in the minus side and the plus side, respectively. These pulses are smoothed through a filter, inputted to the circuit 22g, and the motor 2 is driven or stopped. |
