| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize a structure in which a residual toner is properly removed by electrostatic cleaning units 12a and 12b, even though environment is different between inside and outside of a development device. <P>SOLUTION: Transfer current to be applied to a backup roller 21 is defined by a detection result of a body environment sensor 41. A first toner charge amount corresponding to the detection result of the body environment sensor 41 and a second toner charge amount corresponding to a detection result of an environment sensor 40 in a development device are compared. When the second toner charge amount is equal to or less than the first toner charge amount, the transfer current is corrected according to the difference so as to decrease. <P>COPYRIGHT: (C)2012,JPO&INPIT |
