| 摘要 |
PURPOSE:To eliminate the need to replace a motor even when a frequency is varied by rectifying electric power from an AC power source directly without passing it through a transformer, and driving a platen by a DC brushless motor according to the rectified DC voltage. CONSTITUTION:A reference clock is outputted from a microprocessor 154 and supplied to a phase comparator 111. Consequently, a switching circuit 100 is controlled with the signal corresponding to the phase difference between the reference clock from a PLL circuit 110 and a rotation detection signal to apply a specific voltage to a motor driving circuit 71. A motor driving circuit 71, therefore, drives, the DC brushless motor 35 at the speed corresponding to the supplied voltage value. Consequently, even when the frequency is varied, the need to replace the motor is eliminated, the weight per output is reduced, and the size and weight of the motor are reduced; and the space is utilized efficiently, the efficiency of the motor is improved, and the heating value is reduced, thereby forming an excellent image without any cooling device. |
