Image forming apparatus with multiple image bearers

An image forming apparatus comprising:

• multiple image bearers having respective shafts;
• multiple image bearer gears mounted on the respective shafts of the multiple image bearers;
• a drive source configured to rotate the multiple image bearers;
• a first output gear configured to output a driving force applied by the drive source, the first output gear being a single gear associated with at least two image bearers of the multiple image bearers;
• a second output gear configured to output a driving force applied by the drive source, the second output gear being a single gear associated with at least one image bearer of the multiple image bearers;
• a drive transmission body;
• multiple relay gears having respective shafts and configured to receive and relay the driving force from one of the first output gear or the second output gear directly or via the drive transmission body to the multiple image bearer gears, the multiple relay gears including a first relay gear and a third relay gear to which the driving force is input from the first output gear, a second relay gear to which the driving force is input from the first relay gear, and a fourth relay gear to which the driving force is input from the second output gear;
• and
• multiple drive gears, the multiple drive gears each having a respective shaft defining a center of rotation thereof and configured to connect to the multiple relay gears and the multiple image bearer gears and to transmit the driving force from the multiple relay gears to the multiple image bearer gears, the shaft of each of the multiple drive gears being arranged such that the center of rotation of each of the multiple drive gears is downstream from a corresponding one of the multiple relay gears in a rotation direction of the corresponding one of the multiple relay gears, relative to a virtual line segment connecting a center of rotation of the corresponding one of the multiple relay gears and a center of rotation of corresponding one of the multiple image bearer gears.