| 摘要 |
PURPOSE:To prevent the local excess electrification of a rotary drum and fatal damage caused by the degradation of the property of the rotary drum and a dielectric breakdown by detecting the rotation of the rotary drum and interrupting the output of a corona discharger. CONSTITUTION:When a motor 24 is rotated at constant speed, a rotation detecting circuit 28 outputs a control signal 29 to carry out an action so that a high voltage power source control circuit 31 applies a high voltage to a transfer electrifying unit 20 with a signal 32 from a CPU 35 at prescribed timing set in advance. When the motor 24 is stepped out and its rotation is stopped, the step-out of the motor 24 is judged from a rotation synchronizing signal 27 on the rotation detecting circuit 28, and the output of a high voltage power source circuit is stopped with a control signal 30 regardless of the signal 32. Thus, even if the rotary drum driving motor 24 is stepped out, the deterioration of the rotary drum is prevented. |
