| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for suppressing a change with time in image quality caused by the fact that a developing electric field is changed with time even if a developing device for bringing a toner into a flare state on the insulative circumferential surface of a toner carrier is used. <P>SOLUTION: The developing device carries the toner on the insulative circumferential surface of the toner carrying roller provided with an inner electrode and an outer electrode and applies voltages different from each other to the inner electrode and the outer electrode to form an electric field (flare electric field) for hopping the toner in the circumferential surface portion of the toner carrying roller facing the inner electrode and the outer electrode outside the circumferential surface of the toner carrying roller. In the developing device, such a voltage that a potential difference between the surface of a toner supply roller supplying the toner to the circumferential surface of the toner carrying roller and the circumferential surface of the toner carrying roller is an electric discharge start voltage or higher is applied to the toner supply roller. <P>COPYRIGHT: (C)2010,JPO&INPIT |
