| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing device in an image forming apparatus in which a magnetic brush 10 after a toner thin layer is formed on a developing roller 4 can be reliably separated from a magnetic roller 5 by a stirring member without complicating the configuration of the developing device, and retention of the developer in the gap position between the magnetic roller 5 and the developing roller 4 is avoided for preventing problems such as pitch irregularity, leaking of the developer and decrease in image density. <P>SOLUTION: A vertical developing device is constituted by disposing the stirring member 8a, 8b above the axis of the magnetic roller 5 and disposing the developing roller 4 below the axis. Saturation magnetization of the carrier is controlled to such a level that a magnetic brush 10 formed on the magnetic roller 5 can be collapsed by stirring with the stirring member and that the magnetic brush 10 touches and slides on the developing roller 4 and no retention of the developer is induced in the gap position between the magnetic roller 5 and the developing roller 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
