Patent ID: 7532842

Claim:
A color printing apparatus, comprising: a plurality of photosensitive drums each corresponding to a color, a plurality of motors corresponding to each photosensitive drum, an image forming unit configured to form an image with the photosensitive drums, a print mode setting unit configured to set a first print mode wherein the image forming unit forms the image with all photosensitive drums and a second print mode wherein the image forming unit forms the image with one of the photosensitive drums, while other photosensitive drums are stopped, a controller configured to control the motors to rotate all of the photosensitive drums, wherein if the first print mode occurs consecutively after the second print mode, then the controller controls the motor to continue to rotate the one of the photosensitive drums and starts to rotate the other photosensitive drums to satisfy a positional relationship which decreases fluctuations of rotating speed for each photosensitive drum.