Actuator for lens driving mechanism

An actuator for a lens driving mechanism, the actuator comprising:

• a motor comprising a stator and a rotor which comprises a rotary shaft and a magnet fixed around the rotary shaft, wherein a threaded portion is disposed at a portion of the rotary shaft axially protruding from one end of the motor, and wherein two idle regions are disposed respectively at both ends of the threaded portion;
• a movable structure which meshes with the rotary shaft and to which a lens is attached, wherein the movable structure, when located at the threaded portion, travels along the rotary shaft by a rotation of the rotary shaft, and wherein the motor runs idle with respect to the movable structure when the movable structure is located at the idle region;
• a stopper means configured to restrict an axial movement of the movable structure;
• an open space disposed inside the motor and configured to allow the rotary shaft to axially move;
• an urging means for urging the movable structure toward the motor;
• and
• a recovery means for bringing the movable structure toward the threaded portion of the rotary shaft when the movable structure is moved to one of the idle regions so as to make contact with the stopper means.