Patent ID: 6903777

Claim:
A lens shutter for digital still cameras comprising: a motor having a stator including an energizing coil, having a permanent magnetic rotor reciprocatingly movable for a predetermined angular range between an initial position and a final position in accordance with a direction of a current supplied to said coil, and having a driving pin integrally provided with said rotor and extending in parallel with a rotary shaft of said rotor; at least one diaphragm blade, said diaphragm blade leaving a circular exposure aperture fully open when said rotor is in the initial position, moving to a predetermined exposure aperture regulating position as following said driving pin when said rotor moves from the initial position, and being returned by said driving pin to a fully opened position of the circular exposure aperture when said rotor returns to the initial position; a first forcing member constructed and arranged to urge said diaphragm blade toward said exposure aperture regulating position; a stopper constructed and arranged to keep said diaphragm blade at the exposure aperture regulating position; at least one shutter blade, said shutter blade leaving said exposure aperture fully open when said rotor is in the initial position, moving together with said driving pin to close said exposure aperture while said rotor moves from the initial position to the final position, and moving together with said driving pin to be returned to the fully open position of said exposure aperture while said rotor returns to the initial position; a second forcing member constructed and arranged to urge said rotor against a movement for the final position at least during a period from a state where said diaphragm blade is caused by said first forcing member to abut on said stopper at the exposure aperture regulating position till a state where said exposure aperture is closed by said shutter blade, and to stop said rotor at a rotational position corresponding to the exposure aperture regulating position when said rotor is in vicinity of the rotational position corresponding to the exposure aperture regulating position with the current to said coil being interrupted; and magnetic holding components respectively disposed at plural places facing a peripheral surface of said rotor, and capable of maintaining the stopped position of said rotor by a magnetic force of said rotor, which acts from said rotor thereto, in a fully opened state and a closed state of said exposure aperture even when the current to the coil is interrupted.