Abstract: When forming an image on both sides of set number of sheets of paper, excess paper which remains in an intermediate tray caused by an overlapped feeding of the paper is guided into a bin which has not been in use for the image forming of the above set number of sheet. Further, when some sheets of the paper discharged from the intermediate tray are transferred in an overlapped condition and the paper in the intermediate tray becomes insufficient, the image forming operation corresponding to the insufficient number of sheet of the paper is discontinued, and the sorting operation for the next original starts from a sort bin skipping over some sort bins which should have received the uncopied paper because of overlapped feeding.

Abstract: A device for controlling the charge area of a photoreceptor comprising a detector for detecting the length of a sheet of copying paper, another detector for detecting the length of an image projected area of the photoreceptor, a selecting device for selecting the shorter one between the detected length of the copying paper sheet and that of the image projected area by comparing them with each other, and controls for controlling the charging time of the main charger so as to charge the photoreceptor to an area corresponding to a length selected by the selecting device, whereby the charge area of the photoreceptor is properly controlled so as to correspond to an area necessary to be transferred, even when the length of the image projected area on the photoreceptor differs from that of the copying paper sheet.

Abstract: A magnification selecting device which is capable of continuously varying magnifications by operating either UP or DOWN key and also slowing down the speed of varying mangifications only when these magnifications are in a position close to the predetermined magnification.