| 摘要 |
PROBLEM TO BE SOLVED: To prevent a titanium oxide from flowing through a cleaning device, and further, to prevent the charging up of toner remaining in the vicinity of a cleaning member, after a transfer is performed. SOLUTION: Density data is detected from image data at the time of forming an image, by an image signal processing circuit 14. Cleaning bias power source 9 is controlled by a cleaning bias control means 8, to adjust a cleaning bias applied to a cleaning blade 7, based on the density data. Thus, an abnormal electric discharge and electrification unevenness are prevented, at the time of the electrification, caused by the sticking of the titanium oxide which has flowed through the cleaning device 6 to an electrifying roller 2, and leakage occurring between the toner remaining after the transfer, which is excessively electrified because the electric charge of the toner remaining after the transfer and existing in the boundary part between the cleaning blade 7 and the drum 1 is gradually accumulated by an electric field by the cleaning bias, and the drum 1, is prevented as well. |
