Patent ID: 8437667

Claim:
An image forming apparatus comprising: a main casing; a developing apparatus that is detachably mountable in the main casing and that comprises: a casing that defines a developing chamber and a developer accommodating chamber, the developer accommodating chamber configured to accommodate developer therein, the developing chamber and the developer accommodating chamber being arranged side by side, the casing being formed with a replenishing port for supplying new developer from a developer replenishing unit into the developing chamber, the developer replenishing unit configured to accommodate the new developer, wherein a total developer storage capacity of the developing chamber and the developer accommodating chamber is greater than a developer storage capacity of the developer replenishing unit; an agitator disposed in the developer accommodating chamber, and configured to rotate in the casing to supply developer from the developer accommodating chamber to the developing chamber; and a supply roller disposed in the developing chamber, the replenishing port being located above the supply roller when the developing apparatus is disposed in an orientation in which the developing apparatus is intended to be placed in the main casing; and a control unit configured to: control the supply roller to rotate when the developing apparatus is mounted in the main casing, the supply roller stirring old developer that has already been located in the developing chamber and the new developer, and transporting the old developer and the new developer from the developing chamber into the developer accommodating chamber; and stop the agitator from rotating while the supply roller is being controlled to rotate.