Patent ID: 7158743

Claim:
A developing apparatus for developing a latent image on a latent image carrying member with a magnetic brush, comprising: a developer carrying member carrying one or more magnetic brushes; a first magnet generating a magnetic field to form a first magnetic brush on the developer carrying member; a casing covering the developer carrying member, said casing having an aperture configured to expose the developer carrying member facing the latent image carrying member, and a second magnet being disposed near the aperture at a downstream side from the first magnet with respect to a direction of movement of the developer carrying member, the second magnet generating a magnetic field to form a second magnetic brush on the developer carrying member; wherein the casing includes a concave structure at a position facing the second magnet, the concave structure being concave toward an extension of the second magnetic brush so as to have a larger gap there between the developer carrying member and the casing than a gap at a tip part of the aperture between the developer carrying member and the latent image carrying member.