Patent ID: 7613414

Claim:
A developing cartridge that is attachable to and detachable from an image forming apparatus, comprising: a developing roller that includes a developing roller shaft, which rotates at a time of development, a developing roller member provided at a circumference of the developing roller shaft to carry a developer, and a developing roller gear provided to rotate integrally with the developing roller shaft at one side of the developing roller shaft in an axial direction; a driving force transmitting unit that is disposed on the one side of the developing roller shaft in the axial direction and transmits a driving force from a driving rotator provided in the image forming apparatus to the developing roller gear, the driving force transmitting unit including a driven rotator connectable to the driving rotator and a transmission gear that engages with the developing roller gear; and an electrode member that is disposed on an other side of the developing roller shaft in the axial direction and comes into contact with a power supply member to apply a bias supplied by the power supply member to the developing roller shaft, wherein a direction of the driving force applied to the developing roller gear at an engagement portion between the developing roller gear and the transmission gear when the developing roller gear and the transmission gear rotate, and a direction of a force applied to the electrode member at a contact portion between the power supply member and the electrode member when the power supply member presses on the electrode member are substantially equal to a direction orthogonal to the axial direction of the developing roller shaft.