| 摘要 |
<P>PROBLEM TO BE SOLVED: To ensure stable primary transfer free from the effect of a change in a charge quantity of toner. <P>SOLUTION: A primary transfer bias is a constant voltage bias variably controlled based on ATVC control. A reference density pattern is formed on an intermediate transfer belt 11 and its density is detected by an image density sensor Sp. Based on the result of the detection, a control circuit 23 variably controls a charging bias and a development bias. Further, based on the result of the control of the development bias, a target current at primary transfer is controlled. Since the charge quantity of toner is reflected on the control of the target current, stable primary transfer free from the effect of a change in the charge quantity of toner is ensured. The density is detected and, based on the information about the density, the charging bias and the development bias are variably controlled. Based on the control result of the development bias, the target current for the primary transfer is variably controlled. <P>COPYRIGHT: (C)2007,JPO&INPIT |
