| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus completing adjustment of a transfer current value properly and precisely without reducing productivity of the image forming apparatus even when the adjustment is performed frequently. SOLUTION: When image formation is started, a constant voltage to be applied to a primary transfer roller 54Y is set by performing ATVC control in pre-rotation before image formation. Afterward, every time 200 sheets of image forming are accumulated, a current value is measured while applying the constant voltage between normal images, and a current differenceΔIm from a target transfer current Im is determined. From a linear expression of a voltage-current characteristics of a primary transfer part T1 determined in operation of the latest ATVC control, a voltage correction amount compensating the current differenceΔIm is calculated, and a new constant voltage is set by adding/subtracting the voltage correction amount to/from the previous constant voltage. The new constant voltage is applied to the primary transfer roller 54Y from between the next and subsequent images. COPYRIGHT: (C)2010,JPO&INPIT |
