Patent ID: 7693443

Claim:
An image forming apparatus comprising: a casing; and a process cartridge removably installed in the casing, the process cartridge further includes: a process cartridge frame; a plurality of drum units provided in the process cartridge frame, each of the plurality of drum units including a developing cartridge installation portion; and a plurality of developing cartridges, each of which is removably installed in the developing cartridge installation portion, wherein each of the plurality of developing cartridges further includes a developing cartridge frame including a first sidewall and a second sidewall opposite to the first sidewall; a developing roller disposed between the first sidewall and the second sidewall, the developing roller including a developing roller shaft configured to rotate during development and a developing roller member configured to carry a developing agent thereon, the developing roller member being provided around the developing roller shaft; an electrode disposed on the first sidewall adjacent to the developing roller shaft, the electrode being electrically connected to the developing roller member; and a driven coupling disposed on the second sidewall, the driven coupling being connected to a drive coupling provided in the casing, wherein each of the plurality of drum units further includes a first wall; a second wall opposite to the first wall; an image holding member supported between the first wall and the second wall, the developing cartridge installation portion being formed between the first wall and the second wall; and a bias terminal coupled to the first wall, the bias terminal contacting the electrode when the developing cartridge is installed in the developing cartridge installation portion, wherein a position where the electrode contacts the bias terminal when the developing cartridge is installed in the developing cartridge installation portion is inside an outer shape of the driven coupling when viewed in a direction of the developing roller shaft.