A hypocycloid reducer 70 for reducing rotation of a flat motor 60 to output the speed-reduced rotation to a drum is provided between the drum and the flat motor 60, a rotor shalt member 65 which is rotated with the same rotation number as the flat motor 60 is axially aligned with the drum is provided on the same side as the flat motor 60. An output rotation body 74 for outputting the speed-reduced rotation is axially aligned with the drum and provided on the same side as the drum. Since the rotor shaft member 65 and the output rotation body 74 are axially aligned with the drum, turning force can be transmitted bi-directionally between the rotor shaft member 65 and the output rotation body 74. Therefore, it is possible to eliminate an electromagnetic clutch to reduce the driving apparatus in size and weight, and since wires and control logic of the electromagnetic clutch are not needed for the driving apparatus, the driving apparatus can be reduced in production cost.