| 摘要 |
PROBLEM TO BE SOLVED: To excellently transfer a toner image and to prevent the interference of discharge between a 3rd transfer means and a transfer material separation means by making the volume resistivity of an intermediate transfer body within a specified range and performing the constant-current control of the 2nd and the 3rd transfer means. SOLUTION: An intermediate transfer belt 14a being the intermediate transfer body is a high-resistance endless belt whose volume resistivity is >=10<12> Ω.cm. A transfer device 14c functioning as the 2nd transfer means for transferring a front surface image on a photoreceptor drum 10 to the front surface of recording paper P and a back surface transfer device 14g functioning as the 3rd transfer means for transferring a back surface image on the belt 14a to the back surface of the paper P are respectively constant-current controlled by using constant-current power sources EA11 and EA12. By making the volume resistivity of the belt 14a high resistance, the flow of a current in a lateral direction through the belt 14a and the paper P is prevented between the transfer devices 14c and 14g, the mutual interference of the respective transfer currents is prevented, a transfer condition is made constant, and the transfer of the toner images to the front and back surfaces is excellently performed. |
