| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent image failure such as the soiled back of a transfer medium, which is caused by toner with which an electrostatic charge amount control roller is soiled, the electrostatic charge amount control roller being used for controlling an amount of the electrostatic charges of the toner sticking to the surface of the transfer belt. <P>SOLUTION: Toner sticking to the surface of the transfer belt is electrostatically cleared away in such a manner that the toner is controlled in an amount of electrostatic charges by the electrostatic charge amount control roller 23, and then a cleaning bias is applied to a transfer roller 12, thereby reversely transferring the toner from the transfer belt 21 to the surface of the photoreceptor drum 1. When an amount of toner sticking to the surface of the transfer belt 21 is large, the control roller 23 is separated from the transfer belt 21 until the portion of the belt with the large amount of toner thereon passes through the control roller 23. Then, electrostatic charge cleaning is once conducted. Thereafter, when the portion comes to the control roller 23 again, the control roller 23 is brought into contact with the transfer belt 21 in order to control the amount of electrostatic charges. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
