| 摘要 |
PURPOSE:To obtain a copied picture without being affected by the fluctuation of the frequency of a supplied commercial power source by providing a frequency detection means detecting a change in the frequency of said power source and an optical motor drive source scanning an image forming optical system in response to the detected frequency. CONSTITUTION:The titled device is provided with a pulse generator circuit 76 converting the changing amount of the frequency, which a subtraction circuit 73 subtracting the output of a reference numeric generator circuit 75 detects, into a motor drive signal, and a drive circuit 77 which drives an optical motor 18 in terms of a current or a voltage according to a command from the pulse generator circuit 76. The changing amount of the frequency in the power source is detected, and a DC drive motor being an optical motor is controlled in response to the changing amount. In such a way the fluctuation of the power source frequency of the AC drive motor being a main motor drive source is detected, the motor is controlled in response to frequencies that detect the frequency detection means and the optical motor drive source so that said motor can be driven at a prescribed frequency. The copy providing optimum picture quality is attainable without being affected by the fluctuation of the frequency of the power source. |
