Patent ID: 8346125

Claim:
A process cartridge detachably mountable on a main casing of an image-forming device, the main casing being provided with a coupling member providing a driving force, the process cartridge comprising: a photosensitive cartridge that has a photosensitive drum; and a developing cartridge that is detachably mountable on the photosensitive cartridge, the developing cartridge comprising: a developing roller configured to supply toner to the photosensitive drum; an input gear that comprises a contact portion that is in contact with the coupling member to receive the driving force and a gear portion, the input gear rotating about a rotational axis defining an axial direction when the contact portion receives the driving force, the gear portion being of a cylindrical shape and having an outer circumferential shape formed with gear teeth; and a transmission gear that is meshingly engaged with the gear teeth of the gear portion to transmit the driving force from the input gear to the developing roller, wherein the gear teeth of the gear portion has a pitch circle defined by being meshingly engaged with the transmission gear, the pitch circle of the gear teeth of the gear portion being arranged to overlap with the contact portion in the axial direction of the input gear.