A plurality of helical groove sections are provided on outer peripheral
surfaces of press rollers provided in a curl elimination mechanism. Each
of the groove sections assumes a shape extending in the circumferential
direction of the respective press rollers; that is, a direction oblique
to a transport direction of paper. Hence, when compared with a case where
the groove sections are aligned in the transport direction of the paper,
the paper is less susceptible to traces of the groove sections. Since the
groove sections are provided on the press rollers, an attempt can be made
to enhance dimensional accuracy of or reduce the weight of the press
rollers.