Method and apparatus for eliminating positional deviations of a photosensitive drum driven by a stepping motor which is by half steps

摘要

An apparatus and method for eliminating position deviations of a photosensitive drum which is rotated by a stepping motor driven by full step and half step drive pulses. The apparatus includes a photosensitive drum, a stepping motor which rotates the photosensitive drum; and a controller which controls the stepping motor to be driven with half step drive pulses when the photosensitive drum is being scanned. In the apparatus and method, a scanning starting control is performed by driving the stepping motor by full step drive pulses so that salient poles of the rotor are aligned with salient poles of the stator such that the rotor is in a stable position. The full step drive pulses are switched to half step drive pulses before scanning is started, and the scanning of the photosensitive drum is started on an even numbered half step drive pulse.