In the previous machines, a single motor (the exit/invert motor) drives both the exit roller and the heat pipe. In this machine, however, a new motor has been added for the heat pipe. The exit/invert motor [A] and heat pipe motor (the new motor) [B] are mounted side by side at the rear, upper left corner of the duplex unit. This arrangement improves the paper purge feature that shunts paper from the paper path into the purge tray when a paper jam occurs. These motors are identical.