To provide a driving device in which noise is a little even if it is rotated at high speed, a big driving force can be exactly transmitted and a cost is reduced.

A whirl-stop 82 made of metal is mounted on an output shaft 81 of a main motor 38, and a motor output gear 40 which is a helical gear made of a resin is mounted on the whirl-stop 82. Thus, at the time of driving of the main motor 38, a heat generated from the main motor 38 is not directly transmitted to the motor output gear 40 made of the resin, while the whirl-stop 82 made of metal is exactly secured to the output shaft 81 without expansion. Since the motor output gear 40 is the helical gear made of a resin, engagement thereof is stronger than that of a spur gear. Therefore, noise due to gear noise can be reduced and the big driving force can be exactly transmitted, and since the helical gear is made of a resin, big reduction of the cost is attained.