Patent ID: 8229317

Claim:
A developing unit comprising: a developer carrier configured to carry a developer, the developer carrier having axial end parts; a housing that rotatably supports the developer carrier and that has a supply port through which the developer can be supplied to the developer carrier; and a side sealing member that is disposed between one of the axial end parts of the developer carrier and a portion of the housing adjacent to the supply port and that is configured to be slidingly contactable with the developer carrier; wherein the side sealing member includes an elastic member having an integral base part closely attached to the portion of the housing and plural integral projections protruding from the base part toward the developer carrier in a protruding direction; and wherein a distal end part of each of the projection has an inclination face inclined so that a part of the inclination face is closer to the supply port as the part of the inclination face is farther from the base part in the protruding direction; wherein the side sealing member has a downstream side portion located downstream in a rotational direction of the developer carrier, and a downstream side sealing portion is provided to the downstream side portion of the side sealing member to feed the developer toward a downstream side in the rotational direction.