Patent ID: 8045892

Claim:
A developing unit used in an image forming apparatus having a latent image carrier, the latent image carrier having a surface to carry a latent image thereon, the developing unit comprising: a developer carrier disposed to face the latent image carrier and configured to rotate while carrying two-component developer containing toner and magnetic carrier and to supply the toner to the latent image, carried on the surface of the latent image carrier, in a development area in which the developer carrier faces the latent image carrier; a supply compartment comprising a supply transport member configured to transport the developer in a first direction parallel to an axial direction of the developer carrier and to supply the developer to the developer carrier; a recovery compartment comprising a recovery transport member configured to transport the developer, recovered from the developer carrier after passing through the development area, in a second direction parallel to the axial direction of the developer carrier; a separation member comprising one end portion disposed to face the developer carrier at a facing area, the separation member disposed to separate the supply compartment and the recovery compartment, the supply compartment disposed above the recovery compartment behind the separation member; and a gap provided at the facing area at which the one end portion of the separation member faces the developer carrier, an agitation compartment with an agitation transport member, wherein the agitation compartment receives excess developer of the developer, transported to a downstream end portion of the supply compartment in the first direction in which the supply transport member transports the developer, and recovered developer of the developer, recovered from the developer carrier and transported to a downstream end portion of the recovery compartment in the second direction in which the recovery transport member transports the developer, and supplies agitated developer to the supply compartment by the agitation transport member that, while agitating the excess developer and the recovered developer into the agitated developer, transports the agitated developer in a direction opposite the first direction in which the supply transport member transports the developer; a first separation wall configured to separate the supply compartment and the agitation compartment; and a second separation wall configured to separate the recovery compartment and the agitation compartment, wherein the second direction in which the recovery compartment transports the developer is the same as the first direction in which the supply transport member transports the developer.