| 摘要 |
PURPOSE:To record a fresh image without distortion or strain due to a constant speed even if a power source voltage is varied by supplying power to a synchronous motor by a voltage converter which varies its output voltage in response to the power source voltage. CONSTITUTION:A transformer 37 having a plurality of taps t1-t3 of different output voltages are provided, ON/OFF of control elements 34-36 which are composed of thyristors and triacs are controlled in response to the power source voltage V detected by a power source voltage detector 38, thereby regulating the voltage applied to a synchronous motor MS. When the voltage V is low, the element 34 is turned ON, the when the voltage V is high, the element 36 is turned ON, thereby reducing the variation in the voltage applied to the motor MS. Thus, even if the power source voltage varies, the torque T of the motor MS becomes substantially constant, thereby proving the constant speed rotation of a photosensitive drum. |
