| 摘要 |
PROBLEM TO BE SOLVED: To transfer a toner image well in either case of both-side image formation and surface image formation by changing the value of a transfer current or the value of a transfer voltage for transferring the toner image in the case of the surface image formation and in the case of the both-side image formation. SOLUTION: In the case of image formation, the value of an optimum transfer current in the case of a both-side image formation mode is larger than that in the case of a surface image formation mode. It is because the toner image of a back surface image exists between the back surface of a recording paper P and a toner image receiving body 14a in the case of the both-side image formation mode, so that a transfer electric field is weakened. Consequently, the transfer current value to a transfer device 14c obtained when the toner image of the surface image carried on a photoreceptor drum 10 is transferred to the surface of the paper P is changed between in the case of the both-side image formation mode and in the case of the surface image formation mode. That is, the transfer current value IA2 in the case of the both-side image formation mode is set larger than the transfer current value IA1 in the case of the surface image formation mode. |
