DEVELOPMENT APPARATUS AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a development apparatus and an image forming apparatus that prevent the reduction of density or the occurrence of residual images (ghost images) and can carry out good image forming over a long period, in a development apparatus of the hybrid method using a two-component developer. SOLUTION: The development apparatus has the feature that the surfaces of the toner supporting member and the developer supporting member move in a mutually opposite direction at the part that they are opposite to each other, and the electric field in the closest part of the opposing portion applied in a direction to recover the toner from the toner supporting member to the developer supporting member is in the range from 2.5×106V/m to 5×106V/m, and the share (PD) of the developer in the space of the closest part of the opposing portion satisfies the relationship of the formula (1):0.09≤PD≤650×Dss. COPYRIGHT: (C)2008,JPO&INPIT