Patent ID: 7868575

Claim:
An aperture driving apparatus comprising: a swing unit and a stationary unit, wherein: said swing unit comprises: an aperture plate that partially blocks a light; a coil that is a part of a voice coil motor for obtaining a driving force for driving said aperture driving plate, and a swing arm that supports said aperture plate and said coil, and has a bearing portion between said aperture plate and said coil, and said stationary unit comprises: a swing shaft that engages said bearing portion and swingably supports said swing arm about a swing axis, and a magnet and a yoke that constitute said voice coil motor together with said coil, said magnet applying said driving force to said coil; an angle sensor that detects the swing angle of said swing arm; an evaluating unit that determines an evaluation value used for determining the swing angle by which said swing arm is to be swung; and a control unit that determines the swing angle by which said swing arm is to be swung according to an output of said angle sensor and said evaluation value, to thereby control the swing angle of said swing arm using a closed-loop control technique, wherein, in the direction of said swing axis, the position of a center of gravity of said swing unit is substantially aligned with a position at which said driving force is applied to said coil, and wherein said magnet is disposed on only one side of said coil in the direction of said swing axis, such that the position at which said driving force is applied to said coil is displaced from the center of said coil toward said one side in the direction of said swing axis.