Patent ID: 7123862

Claim:
An image forming apparatus comprising: an amorphous silicon photosensitive member; two or more developing means provided in respect to the amorphous silicon photosensitive member; one of the developing means being a magnetic-toner developing means having a magnetic toner, and the remaining developing means being a color developer developing means having a developer containing a non-magnetic color toner; and a cleaning means provided in contact with the surface of the amorphous silicon photosensitive member to clean the surface of the photosensitive member; said magnetic toner having a weight-average particle diameter D 4 of from 4.0 μm to 10.0 μm and a ratio thereof to number-average particle diameter D 1 , D 4 /D 1 , of from 1.0 to 2.0; and where the true density of said magnetic toner is represented by d (g/cm 3 ) and the number of magnetic particles not passing through a mesh with an opening of 34 μm which are contained in m (g) of said magnetic toner is represented by n, the number N (=n/(m/d)) of magnetic particles not passing through a mesh with an opening of 34 μm which are contained in the unit volume of said magnetic toner satisfying the following expression: 3.5<N<105.