(57) The invention relates to an electrophotographic printer which can make printing first
on the front side of a sheet of paper and then on the back side of the same sheet
with conformity between the front and back sides in the head-bottom arrangement of
the printed images. The printer has a photocounductive drum (20) which can be rotated
both in a normal direction and in the reverse direction, an exposure unit (30) to
produce electrostatic latent images on the drum surface, first developing means for
developing the latent images with a toner when the drum is rotating in the normal
direction, second developing means for developing the latent images with a toner when
the drum is rotating in the reverse direction, a transfer unit (40) for transferring
the developed images to a sheet of paper, and first and second fixing means (50A,50B)
which are oppositely arranged with respect to the transfer unit. For printing on the
front side of the paper sheet, the sheet is passed through the transfer unit (40)
in a first direction toward the first fixing means while the drum is rotating in the
normal direction. For printing on the back side of the sheet, the sheet is further
conveyed by a returning route (60) which turns so as to reverse the sheet and extends
to the transfer unit, and, while the drum is rotating in the reverse direction, the
reversed and returned sheet passes through the transfer unit in the opposite second
direction toward the second fixing means (50B).
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