PURPOSE: To enable to securely damp the vibration of a type wheel without being affected by the inertia of the type wheel itself, by providing a delaying means for delaying a driving current impressed on a motor for rotating a type wheel on a printing head.

CONSTITUTION: In a rotation controller, a positional error converter 20 outputs a signal X when the absolute value of an inputted positional error is not larger than a predetermined value, and outputs a signal Y for the pierod of time for which a signal I is inputted when the inputted positional error exceeds the predetermined value. A signal X1 from an OR gate 23 is inputted into an integrating circuit 21, the first time constant circuit is operated, and the second time constant circuit is operated by the signal Y. On the other hand, a timer 22 generates an output signal for a predetermined period of time on being triggered by the trailing edge of a signal from an AND gate 18. At times other than the time of an initializing operation, the value of the driving circuit supplied to the motor 1 increases gradually. Accordingly, vibrations of the type wheel are securely damped immediately after the start of rotation thereof.