| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a blade driving device having simple structure and improved shutter speed, and an optical instrument provided with the same. <P>SOLUTION: A rotation angle range of a rotor is limited to an actuation angle range smaller than the full rotation angle range of the rotor capable of rotating by the excitation of a stator. When the rotor is positioned at a first end of the actuation angle range, a blade overlaps an opening. When the rotor is positioned at a second end of the actuation angle range, the blade retracts from the opening. The actuation angle range includes a position where the torque of the rotor is maximum in the full rotation angle range when the rotor is rotated in the first direction in the case where the rotation angle range of the rotor is not limited. An energizing member directly or indirectly energizes the rotor in the second direction in a section from at least a middle position in the actuation angle range to the first end. <P>COPYRIGHT: (C)2013,JPO&INPIT |
