Image transferring and recording medium conveying device and image forming apparatus including the same

An image transferring and recording medium conveying device for an image forming apparatus of the present invention includes a belt (11) forming a nip (N) for image transfer between it and an image carrier (W) and conveying a recording medium (P) via the nip to thereby transfer a toner image formed on the image carrier to the recording medium. A bias applying device applies a bias for image transfer to the nip. Assume that an image transfer bias Tb is applied during a leading edge interval in which the leading edge portion of the recording medium between the leading edge and a preselected position in the direction of medium conveyance moves away from the nip, and that an image transfer bias Ta is applied to the nip during a remaining interval in which the remaining portion of the recording medium moves away from the nip. Then, a controller switches the image transfer bias Tb within a range lower than the image transfer bias Ta.