| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suppressing an image density difference resulting from resistance difference, by reducing partial resistance difference in the axial direction of a transfer roller on which toner images are consecutively transferred to recording materials of one and the same size. SOLUTION: When images are formed on a recording material P105 of A3 size after the images are consecutively formed on≥100 sheets of recording material P104 of A4 size, idle transfer is carried out by supplying power to the transfer belt and idly rotating the belt while the maximum voltage of the same polarity as that assigned for image formation is applied to a secondary transfer roller 40. Thus, current is caused to flow so as to concentrate in the area B where a rise in resistance value is delayed since current is less by a degree corresponding to the resistance value of a recording material during the consecutive image formation. Thereby the resistance value is increased to eliminate the resistance difference between the areas A and B. COPYRIGHT: (C)2009,JPO&INPIT |
