Patent ID: 8374525

Claim:
An image forming apparatus comprising: an apparatus body; a tandem photosensitive drum unit which holds a plurality of photosensitive drums to be in parallel with each other, and is movably mounted in the apparatus body along an array direction of the photosensitive drums; a developing cartridge which is provided for each of the photosensitive drums, supports a developing roller for supplying developer to the corresponding photosensitive drum, and is configured to be detachably mounted in the tandem photosensitive drum unit; a translation member which is provided in the apparatus body to be movable linearly in the array direction; a first supporting shaft which is provided on the tandem photosensitive drum unit for each of the developing cartridges; and a pivoting member which is rotatably supported by the first supporting shaft, wherein the pivoting member includes: an abutting portion which is provided on one side with respect to the first supporting shaft to abut the translation member along the linear movement of the translation member; a pressing portion which is provided on the other side with respect to the first supporting shaft, opposes a predetermined portion of the developing cartridge, and is configured to press the predetermined portion in a direction in which the developing roller is separated from the photosensitive drum along the linear movement of the translation member after the translation member abuts the abutting portion; and a spring portion which is configured to apply a biasing force in a direction in which the pressing portion is separated from the predetermined portion.