PURPOSE: To realize the exact lowering of holder member to printing position by a method wherein the controlling means, in which initial setting control to a motor performed by abutting engaging member against anchoring member through the pivoting of the motor to its reverse rotational direction and the following pivoting of the motor to its normal rotational direction by the predetermined angle is continuously repeated twice, is provided.

CONSTITUTION: The rotational frequency of a DC motor 16 is changed by pulse width modulation control. A control device C determines the ratio of the time, for which driving current is fed to the motor 16, to the predetermined period of time or duty ratio so as to make the rotational speed of the motor equal to the set rotational. speed. The pulse signal of the duty ratio is fed to a driving circuit 81 so as to output the driving current corresponding to the pulse signal to the motor 16. In a ROM 88, driving controlling program for driving the motor 16 in order to carry out printing action and erasing action, driving program for driving respective motors 37-39 interlocking with the printing action and the erasing action, and the like are stored.