To provide a driving mechanism capable of fixing a member to be driven with a small, simple structure and high fixing force without employing an electromagnetic clutch and allowing low driving force for moving the member to be driven.

This driving mechanism is provided with a cylindrical outer race 21, an inner race 30 turnably provided in the outer race 21 and installing a member to be driven, and a levers 42 inserted in a gap formed between the outer race 21 and the inner race 30 and rotationally moving along the inner peripheral surface 21A of the outer race 21. In the driving mechanism, rotationally moving the levers 42 by means of a motor rotationally moves the inner race 30 to move the member to be driven. The driving mechanism is provided with rollers 49, 50 cutting into the gap formed between the outer race 21 and the inner race 30.