Patent ID: 8855524

Claim:
A developing apparatus comprising: a housing having an opening; a developing roller that is arranged so that a part of a circumferential surface of the developing roller is opposed to the opening of the housing, is rotatably supported to the housing and is configured to carry developer on the circumferential surface of the developing roller; a seal member that is fixed to the housing to be opposed to the developing roller in both end portions of the opening in a rotational axis direction of the developing roller and is configured to sliding-contact the circumferential surface of the developing roller; and a layer thickness regulating member configured to contact the circumferential surface of the developing roller via developer and to regulate a thickness of a developer layer on the circumferential surface of the developing roller, wherein the seal member comprises: a base made of an elastic body; a sliding contact portion made of fiber having elasticity and extended from the base, wherein the sliding contact portion is configured to sliding-contact the circumferential surface of the developing roller, wherein the layer thickness regulating member has a first end portion that is supported by the housing, an intermediate portion, and a second end portion, wherein the layer thickness regulating member is bent from the intermediate portion to the second end portion to face the seal member, wherein, in a region between the first end portion and the intermediate portion, the fiber of the sliding contact portion fills spaces between the layer thickness regulating member and the base; and in a region between the intermediate portion and the second end portion, the fiber of the sliding contact portion is positioned (i) between the base and the layer thickness regulating member and (ii) between the layer thickness regulating member and the developing roller wherein the bent portion is bent to have such a radius of curvature that an entire bent portion from the intermediate portion to the second end portion thereof is spaced from the circumferential surface of the developing roller, and wherein an angle θ between a first base line connecting a center of curvature and the intermediate portion and a second base line connecting the center of curvature and the second end portion is within a range of 0°<θ≦90°.