The invention provides a double-faced image formation system that prevents transfer
and adhesion of a lubricant to an image retaining conveyer and an intermediate
transfer part. The system is provided with, on a return path for reversing and
conveying a sheet having toner images fixed on one side thereof, a front face electrifying
unit and a rear face electrifying unit. Oil adhered on the rear face of the sheet
in a fixation unit by the rear face electrifying unit is electrified to a negative
polarity, and the oil adhered on the rear face is made impossible to transfer to
an intermediate transfer belt. The oil adhered on the front face of the sheet in
the fixation unit by the front face electrifying unit is electrified to a positive
polarity, and the oil adhered on the front face is made impossible to transfer
to a secondary transfer conveyance belt.
