| 摘要 |
PURPOSE:To synchronize the speed of both motors by controlling the source voltage for a DC brushless motor for driving a photosensitive drum according to the rotating speed of a DC motor for driving an optical system. CONSTITUTION:A DC motor is smaller in size with less generation of heat and does not require switching to meet the frequency of a commercial power source (50Hz or 60Hz) and therefore an optical system is driven by a DC motor 62. A DC brushless motor for driving a photosensitive drum runs at the speed proportional to the source voltage 58 thereof if load is roughly constant. The clock pulse generated by a microprocessor 60 changes over the phase via a driver 61 to run a motor 62. The difference between the clock pulse and the pulse of an encoder 64 synchronized with the rotation of the photosensitive drum is detected with a comparator 63 which controls the voltage 58 for the brushless motor according to the difference from a reference voltage generating circuit 66 thereby running both motors in synchronization. |
