Patent ID: 8498554

Claim:
An image forming apparatus comprising: a drum unit comprising a photosensitive drum and a drum drive input member, which is rotatable, and which is configured to receive drum driving force for rotating the photosensitive drum; a developing unit comprising a developing roller disposed so as to face the photosensitive drum and a developing drive input member, which is rotatable, and which is configured to receive developing driving force for rotating the developing roller, the developing unit configured to move between a first position in which the developing roller is in contact with the photosensitive drum and a second position in which the developing roller is spaced apart from the photosensitive drum; a drum drive transmission member that is configured to engage with the drum drive input member and configured to transmit the drum driving force to the drum drive input member; and a developing drive transmission member that is configured to engage with the developing drive input member and configured to transmit the developing driving force to the developing drive input member, wherein a rotational center of the drum drive input member is substantially coincident with a rotational center of the drum drive transmission member, and wherein a rotational center of the developing drive input member is substantially coincident with a rotational center of the developing drive transmission member.