Patent ID: 8078042

Claim:
A vibration-proof lens unit comprising: a lens holder that holds a vibration-proof lens; a support that supports the lens holder in a manner to be movable within a plane orthogonal to an optical axis of the vibration-proof lens; an engaging section that engages the lens holder with the support such that the lens holder can move (i) in a rotational direction around an axis line parallel to the optical axis of the vibration-proof lens and (ii) in a direction of a rotational radius orthogonal to the axis line; a rotational driving unit that moves the lens holder in the rotational direction; a linear driving unit that moves the lens holder in the direction of the rotational radius, and three support points that are arranged to surround the optical axis of the vibration-proof lens and a center of mass of a movable part that includes the lens holder and moves integrally with the lens holder, and that support the lens holder on the support, wherein the rotational driving unit and the linear driving unit are voice coil motors that each include (i) a magnet provided on one of the lens holder and the support and (ii) a coil and a yoke provided on the other of the lens holder and the support to face the magnet, the rotational driving unit and the linear driving unit are provided on opposite sides of a line connecting two of the three support points, one of the rotational driving unit and the linear driving unit being provided on the opposite side of the line from the center of mass and the optical axis of the vibration-proof lens, (i) a distance A between the line and a center of the magnet provided to said one of the rotational driving unit and the linear driving unit, (ii) magnetic attraction B of the magnet of said one of the rotational driving unit and the linear driving unit, (iii) a distance C between the center of mass and the line, (iv) weight D of the movable part, (v) a distance E between the line and a center of the magnet provided to the other of the rotational driving unit and the linear driving unit, and (vi) magnetic attraction F of the magnet of the other of the rotational driving unit and the linear driving unit satisfy Expression 1, and Expression 1 is defined as: A×B<C×D+E×F.