| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing device and an image forming apparatus which attain the uniform reproduction of a fine line and a small-size dot, no carrier sticking and a stable developer charge quantity, then an image stable in quality can be obtained over a long period of time. <P>SOLUTION: The developing device has a developer carrier which is disposed opposite to the image carrier, carries a two-component system developer comprising magnetic carrier particles and toner on the surface, forms a development nip between the image carrier and the developer carrier, supplies toner to the image carrier and develops an electrostatic latent image on the image carrier, wherein the magnetic carrier particles have coated films comprising at least binder resin and particles on carrier core material, the particles included in the coated film have a resistivity of 10<SP>12</SP>Ωcm or more and have a coverage for the core material of 70 to 95%, and a control means that drives the developer carrier besides imaging time, based on the ratio of image area for the number of unit output sheets of the image forming apparatus is disposed. <P>COPYRIGHT: (C)2007,JPO&INPIT |
