| 摘要 |
PROBLEM TO BE SOLVED: To make printing speed high by discriminating image size and efficiently utilizing a toner image receiving body. SOLUTION: A surface image on a photoreceptor drum 10 is transferred on the upper surface side of recording paper P altogether by a transfer device 14c on which voltage having a reverse polarity to the polarity of toner is impressed. Next, a back surface image on the toner image receiving body 14a is transferred on the lower surface side of the recording paper P altogether by a back surface transfer device 14g on which the voltage having the reverse polarity to the polarity of the toner is impressed. In the case the image size is that plural toner images can be carried on the body 14a at the time of forming plural double-sided images, the plural back surface images are continuously carried on the body 14a, and then operation that forming the surface image on the drum 10 and forming the double-sided image on the recording paper P are continuously performed is repeated. In the case the image size is that the single toner image can be carried on the body 14a, the back surface image is singly carried on the body 14a, and then forming the surface image on the drum 10 and forming the double-sided image on the recording paper P are repeated. |
