CPC G03G 15/0928 (2013.01) [G03G 9/1136 (2013.01); G03G 9/1139 (2013.01); G03G 15/0812 (2013.01); G03G 2215/0609 (2013.01)] | 8 Claims |
1. A developing device, comprising:
a developing container that stores a two-component developer containing a magnetic carrier and a toner;
a developer carrying member that is rotatably supported on the developing container and carries the developer on an outer circumferential surface thereof; and
a regulation member that is arranged to be opposed at a prescribed distance to the developer carrying member,
the developing device developing an electrostatic latent image formed on a surface of an image carrying member into a toner image,
wherein
the developer carrying member includes:
a developing sleeve that is rotatable, carries the developer, and has a surface on which a magnetic brush is formed; and
a magnet that is unrotatably secured in the developing sleeve and has a plurality of magnetic poles arranged at a prescribed distance from each other in a circumferential direction, which include a regulation pole that is arranged at a position opposed to the regulation member and a downstream-side magnetic pole that is arranged on a downstream side of the regulation pole with respect to a rotation direction of the developing sleeve,
the magnet is such that a vertical magnetic force gradient [mT/°] has a local minimum value C within a range of 10°, upstream in the rotation direction of the developing sleeve, of a position at which a vertical magnetic force is 0 [mT] between a downstream-side surface of the regulation member and the downstream-side magnetic pole with respect to the rotation direction of the developing sleeve.
|