Abstract: An image forming apparatus includes an apparatus body having a photosensitive drum for carrying an image, a developing unit, provided within the apparatus body, including a developing agent storage unit for storing a developing agent and a developing roller for supplying the developing agent in the developing agent storage unit to the photosensitive drum, a driving gear, provided detachably to the developing roller of the developing unit, for driving the developing roller when the driving gear is connected to the developing roller, and a rigid shield member, attached removably in the developing unit, for separating the developing agent storage unit from the developing roller in the developing unit and separating the developing roller from the driving gear when the shield member is attached, and for making the developing agent storage unit communicate with the developing roller and connecting the developing roller and the driving gear when the shield member is removed.

Abstract: In an image forming apparatus which tranfers a toner image to a sheet in accordance with image information, a first connector, is fixed to the outside of a developing device which supplies a developing agent to the apparatus. The first connector electrically connects the body and the developing device. A second connector, adapted to be connected to the first connector, is fixed to a mounting portion for holding the developing device in the apparatus. When the developing device is attached to the mounting portion, the first and second connectors are connected to each other. The apparatus also includes a movable handle which would or would not allow a removable lid to fully close.

Abstract: Disclosed is a developing device, which develops an electrostatic latent image by applying a toner thereto. The device is provided with an auto-toner adjuster, which detects the toner content of a developing agent, and resupplies the toner in accordance with the detected value, thereby keeping the toner content constantly at a predetermined value. At the shipment from the factory, the developing device is sealed hermetically, storing the developing agent used in setting the toner content by the toner adjuster.