| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent transfer failure resulting from a sudden resistance change that occurs immediately after power is supplied after an ion conductive transfer roller is left for a long period of time. <P>SOLUTION: A current during the application of Vp1 is detected. Then, a value obtained by averaging it with respect to one rotation of the transfer roller is assumed to be a first detection current value Ip1. Subsequently, without a break, the same transfer bias Vp1 is applied to the transfer roller 9 during its one rotation. A value obtained by averaging the current detected then is assumed to be a second detection current value Ip2. When a difference ΔIp(n+1-n) between an nth detection current value Ipn and (n+1)th detection current value Ip(n+1) becomes smaller than a predetermined threshold ΔIp, it is assumed that the resistance value of the transfer roller has become stable, a multiple pre-rotation operation therefore is finished to be ready for the start of an image forming operation. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
