Patent ID: 7116932

Claim:
A developing unit that develops a latent image carried on a latent image carrier of an image forming apparatus, comprising: a developer containing unit that contains developer; a developer carrier that has a moving surface, and carries the developer on the moving surface; a magnetic force generator that attracts the developer onto the moving surface by a magnetic force generated from a plurality of magnets arranged along the moving surface; and a restricting member that restricts a layer thickness of the developer carried on the moving surface, wherein, the magnets include a restricting magnet that is arranged closest to the restricting member and has a restricting magnetic pole, a first surface of the restricting magnet toward the moving surface and a second surface of the restricting magnet toward an upstream adjacent magnet that is arranged so as to be adjacent to an upstream side of the developer carrier in a direction of movement of the moving surface and has an upstream adjacent magnetic pole forming a ridged corner portion, and the ridged corner portion is chamfered.