Developing apparatus using magnetic developer

摘要

A developing apparatus for electrophotography is disclosed which comprises a toner hopper as a vessel of a magnetic developer, the toner hopper having an opening formed between one side plate of the toner hopper and a developing sleeve to effect delivery and recovery of the magnetic developer, the developing sleeve being rotated from a developing zone for developing a latent image on a latent image-bearing member with the magnetic developer toward the opening and the plate of said toner hopper other than the opening being in abutting contact with the surface of the developing sleeve, a magnet roll comprising a plurality of magnets, which is rotated in the same direction as the rotation direction of the developing sleeve on the inner side of the developing sleeve, and a stopper for regulating the zone of delivery of a layer of the magnetic developer on the surface of the developing sleeve by causing the top end of the stopper to abut on or come close to the surface of the developing sleeve along the direction of the rotation axis of the developing sleeve, wherein the rotational speed of the developing sleeve and the number of rotations of the magnet roll are set so that the thickness of the layer of the magnetic developer is adjusted to a desired value.