The present invention is capable of changing the system speed quickly and highly accurately while using a CVT device with an advantage in its quietness to transmit a driving force to rotative parts.Specifically, in the case of using a sheet of thick paper as a recording sheet, the controller changes, for each of the pulleys, the distance between the pulley segments (S204) while starting up the DC motor as the driving source (S202). After that, the controller performs the feedback control on the rotation of the DC motor, based on a detection signal received from the encoder of the load shaft of the driven pulley, to achieve the target rotation speed of the load shaft (S206: NO, S207).