An image forming device, having a contact-type transfer carrying unit for
improving the separation property of the transfer paper from an image
supporter, such as a photoreceptor, is provided. The belt resistance from
the applying current to the transfer belt and the actually applied voltage
is determined to control to switch the front-end current switching timing
and the current between the transfer papers. If the belt resistance is
lowered, the timing for switching the front-end current is delayed and the
current between the transfer papers is reduced. If the belt resistance is
increased, the timing is advanced and the current is increased. The bias
current is applied in a non-image region on the transfer paper, rather
than the region between papers in conventional art.
