Patent ID: 8478158

Claim:
A developing device comprising: a first frame that has a pair of side walls arranged to be opposite each other and a connection wall connecting the side walls; a second frame that has a beam-like portion forming an opening together with the side walls and the connection wall of the first frame when combined with the first frame; a frame seal that is disposed in a gap which is formed between each of the side walls and the beam-like portion when the first frame and the second frame are combined with each other, and the frame seal is disposed so as to block the gap between each of the side walls and the beam-like portion; a developer carrier that is exposed to an outside through the opening and is configured to carry a developer; a layer thickness regulating blade that is disposed over each of the side walls and the beam-like portion and configured to regulate a thickness of the developer on the developer carrier; and a blade rear seal member that is disposed between the layer thickness regulating blade and the beam-like portion so as to block a gap between the layer thickness regulating blade and the beam-like portion, wherein the frame seal has an elastic layer and an adhesive base material, an end of the frame seal on the blade rear seal member side is bent such that the elastic layer comes into close contact with the blade rear seal member, and the adhesive base material is provided on the side of a bent portion of the end of the frame seal in contact with the first frame or the second frame.