Patent ID: 8688010

Claim:
A developing cartridge comprising: a frame having a first side plate and a second side plate spaced opposite from the first side plate; a developer carrying member which is rotatably supported between the first side plate and the second side plate, and which is configured to carry developer; a developer supplying member which is rotatably supported between the first side plate and the second side plate, and which is configured to supply developer to the developer carrying member; a driving force input member which is rotatably supported by the first side plate, and to which driving force is input from outside; a primary developing gear which is provided at an end of the developer carrying member at the side of the first side plate, and to which the driving force from the driving force input member is transferred; and a supply gear which is provided at an end of the developer supplying member, and to which the driving force from the driving force input member is transferred, wherein the driving force input member and the supply gear are arranged such that at least parts of projections thereof in a direction of a rotation axis of the developer supplying member on a projection plane orthogonal to the rotation axis overlap, wherein the driving force input member and the supply gear are configured such that the supply gear rotates in a first rotation direction as the driving force input member rotates in a second rotation direction opposite to the first rotation direction, and wherein the developer supplying member is arranged such that the rotation axis of the developer supplying member falls within the projection of the driving force input member on the projection plane in the direction of the rotation axis.