| 摘要 |
PURPOSE:To collect a leaked magnetic particle to a developer holding member, and to prevent a bad influence by providing a magnetic particle holding magnetic pole on a prescribed position in the holding member, and setting a distance between the holding member of the magnetic pole position and a photosensitive body to >=1mm. and <=20mm.. CONSTITUTION:In a developer holding member 12, a magnetic particle holding magnetic pole 20 is provided on the downstream side from a position opposed to a photosentive body, and a distance L to the photosensitive body in a position of the magnetic pole 20 is set to >=1mm. and <=20mm.. When a mixture of a magnetic particle and a non-magnetic developer is supplied to the holding member 12 and rotated in the direction as indicated with an arrow (b), a base layer 16 is formed by a magnetic bursh, and a thin layer of a developer is supplied onto the holding member 12, but depending on a condition, sometimes the magnetic particle flows out. In that case, it does not adhere to a photosensitive body 11 since the magnetic pole 20 exists, but is attracted to the member 12 and returned to a vessel 13. Therefore, scattering, etc. of the magnetic particle are prevented, and its bad influence can be prevented effectively. |
