| 摘要 |
PURPOSE: To provide an image forming device capable of speeding up a double-sided image formation and improving transferring performance in the case of a low humidity without forming a defective image caused by oil-sticking, etc., resulting from double- sided image formation. CONSTITUTION: This device is provided with a 1st image forming mode in which the toner images of respective colors formed on respective image carriers are successively superposed and directly transferred on one surface of a recording material, and a 2nd image forming mode in which the toner images of the respective colors are transferred altogether on the other surface of the recording material after the toner images of the respective colors formed on the image carriers are successively superposed and transferred on a recording material carrier. The image is formed on the same recording material in the 2nd mode and the 1st mode in this order. In the 2nd mode, the toner images of the respective colors on the recording material carrier are transferred altogether by using transfer charge at the time of transferring the toner image on the image carrier in the 1st mode. Thus, the image is formed on both surfaces by carrying the recording material once, so that the double-sided image formation is speeded up and the defective image caused by the oil-sticking is not formed. |
