| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing device in which a two-component developer is picked off in a preferable state from a developer carrier and a degradation in the developer carrier and the developer is suppressed, and to provide an image forming apparatus using the same. <P>SOLUTION: The developing device includes a development housing 2 that is open opposite to an image carrier 1 carrying an electrostatic latent image and can house a two-component developer (developer) D containing a toner and a magnetic carrier, and a developer carrier 3 disposed opposing to the opening of the development housing 2 and capable of carrying and conveying the developer D, wherein the developer carrier 3 has a rotatable developing sleeve 3a and a magnet body 3b having magnetic poles of opposite polarities alternately arranged and fixed inside the developing sleeve 3a. The magnetic body 3b has such a magnetic force distribution that both of the normal component and the tangential component of the magnetic flux density between adjoining magnetic poles of opposite polarities decrease, and has a pick-off portion P where the developer D on the developing sleeve 3a can be released since the developer overcomes by the effect of gravity G and centrifugal force CF against the holding force by the magnetic force distribution. <P>COPYRIGHT: (C)2008,JPO&INPIT |
