Patent ID: 7783229

Claim:
An image forming apparatus comprising: a main body; a photosensitive member; a developing device detachably mountable to the main body, and configured and positioned to engage the photosensitive member, the developing device including a roller; a first support portion positioned at a first surface of the developing device, the first support portion being a roller and the first surface being a lower surface, the roller of the developing device being between the first surface and the photosensitive member; a second support portion positioned at a second surface of the developing device in a first direction of an axis of the roller; and a third support portion positioned at a third surface of the developing device in a second direction of the axis of the roller, wherein the first, second and third support portions are configured and positioned to support the developing device to move back and forth in a direction that the developing device is urged toward the photosensitive member.