Patent ID: 8886083

Claim:
An image forming apparatus comprising: a photosensitive drum; a developing unit including a developing agent bearing member configured to supply a developing agent to the photosensitive drum, the developing agent bearing member having an axis extending in an axial direction and defining a first side and a second side opposite to the first side in the axial direction; and a casing configured to support the photosensitive drum and the developing unit, the casing having an opening at a position corresponding to the first side, the developing unit being detachable from and attachable to the casing through the opening, wherein the developing unit is configured to move selectively to one of a proximity position where the developing agent bearing member is in contact with or in proximity to the photosensitive drum, a separated position where the developing agent bearing member is spaced apart from the photosensitive drum while a parallel positional relationship between the developing agent bearing member and the photosensitive drum is maintained, and a pivoted position where the developing agent bearing member is pivotally moved about a portion of the developing agent bearing member at the second side from the separated position in a direction away from the photosensitive drum, the developing unit being configured to be detached from and attached to the casing along the axial direction in a state where the developing unit is at the pivoted position.