A rotation force transmission mechanism (30) includes a torque limiter (50), a breaking member (60) and a clutch member (55). The torque limiter (50) is configured to couple the first rotating member (35) and the driving source (40) to each other so as to able to transmit the rotation force until a torque of a predetermined value is applied, and to decouple from each other if a torque larger than the predetermined value is applied. The braking member (60) is configured to apply a torque exceeding the predetermined value to the first rotating member (35). The clutch member (55) is capable of being switched into a transmission state in which the rotation force can be transmitted to the first rotating member (35) and an interruption state in which the transmission of the rotation force is interrupted, in the second rotation force transmission path (P2).