Patent ID: 7831192

Claim:
An image forming apparatus, comprising: a first and a second sheet feeding sections for accommodating sheets before printing in a stacked manner; a first sheet conveying section including first conveying members and adapted to convey a sheet received from the first sheet feeding section; a second sheet conveying section including second conveying members and adapted to convey a sheet received from the second sheet feeding section; a single first image forming unit for forming a black toner image, and including a first photoconductive drum, a first developing device, and a first cleaning roller as driven members; a plurality of second image forming units for forming color toner images and including second photoconductive drums, second developing devices, and second cleaning rollers as driven members; a controlling unit for controlling operations of the first image forming unit and the second image forming units; a first driving source for driving the first conveying members; and a second driving source for driving the second conveying members, wherein at least one of the first developing device, the first cleaning roller, and the second cleaning rollers is driven by the first driving source, and the rest of the first developing device, the first cleaning roller and the second cleaning rollers that is not driven by the first driving source is driven by the second driving source, rotational directions of the first and second cleaning rollers are opposite to those of the first and second photoconductive drums, and the controlling unit performs a driving control of rotating the first cleaning roller and the second cleaning rollers by the first driving source and the second driving source prior to the rotations of the first photoconductive drum and the second conductive drums when the first image forming unit and the second image forming units are started.