| 摘要 |
PURPOSE:To improve an image quality by separating a magnetic brush transferred to a developing roller from a magnetic roller, into non-magnetic toner and magnetic particle by a magnetic material control member, and making only the non-magnetic toner adhere to the developing roller. CONSTITUTION:In a position where toner and magnetic particle carried by a magnetic roller 8 contact or stand close to a developing roller 11, the developing roller 11 and a magnetic material control member 15 form a magnetic circuit by a magnetic field of the magnetic roller 8. Accordingly, force attracted onto the developing roller 11 operates on a magnetic brush on the magnetic roller 8, and a part of the magnetic brush is transferred to the developing roller 11 from the magnetic roller 8. Also, by passing through the magnetic material control member 15 provided opposingly on the developing roller 11, the magnetic particle is shackled electrically to the upstream side of the magnetic material control member, dropped downward, and a toner thin layer which is suitable for a development is formed on the developing roller 11. In this way, an image of a good quality having no fog is obtained. |
