Image Forming Apparatus

An image forming apparatus configured to form an image on a sheet, comprising

• a drive source attached to a body of the image forming apparatus and configured to generate driving force;
• a rotating body arranged on the body of the image forming apparatus and configured to be rotated by the driving force supplied from the drive source;
• a processing unit comprising an operable member and detachably attached to the body of the image forming apparatus, the operable member being driven by the driving force transmitted from the rotating body;
• and
• a joint configured to switch transmission and disconnection of the driving force from the rotating body to the processing unit by moving along an axial direction of the rotating body between a first position, in which the joint is engaged with the processing unit, and a second position, in which the joint is separated from the processing unit,
• wherein the joint is rotatable by the driving force transmitted from the rotating body in a coaxial position with respect to the rotating body and switches transmission and disconnection of the driving force by moving along the axial direction;
• wherein the rotating body comprises an input rotating body, which is subject to the driving force input in the rotating body and rotatable by the driving force, and an output rotating body, which is arranged coaxially with respect to the input rotating body and rotatable integrally with the input roller to output the driving force;
• and the rotating body provides accommodating space, which accommodates at least a part of the joint when the joint is separated from the processing unit.