Patent ID: 8059986

Claim:
A method of assembling a cartridge attachable to and removable from a body of an image forming apparatus, the cartridge including a developer case having an opening, a rotatable developing roller disposed in the opening and configured to develop a latent image formed on an image bearing member, a bearing disposed on an outer side with respect to the developer case in a longitudinal direction of the developing roller and configured to bear a shaft of the developing roller allowing rotation thereof, a driving force transmitter disposed on the outer side with respect to the bearing in the longitudinal direction and having an engaging portion configured to engage with the shaft of the developing roller so that a force for rotating the developing roller is transmitted to the developing roller, and an end member disposed on the outer side with respect to the bearing in the longitudinal direction, the method comprising: resting the driving force transmitter on the end member, the end member staying on the developer case; inserting the shaft of the developing roller into the bearing so that the shaft of the developing roller is supported by the bearing; and engaging the shaft of the developing roller with the driving force transmitter after moving the shaft of the developing roller toward the outer side with respect to the bearing in the longitudinal direction and releasing the driving force transmitter that has been rested on the end member from the end member.