Patent ID: 6532199
Filing Date: 2003-03-11
Classification: G11B,H02K

Abstract:
An apparatus for controlling the position of a lens, the apparatus comprising:a carriage having a center of mass; an actuator having a center of mass, the actuator being suspended from the carriage at an initial position, and movable relative to the carriage; a lens disposed in the actuator, the lens defining an optical axis that substantially intersects the center of mass of the actuator and the center of mass of the carriage, suspensory forces acting on the actuator thereby being symmetric about the optical axis; and a focusing drive for the actuator, the focusing drive producing a plurality of focusing forces that are balanced and symmetric about the optical axis to displace the actuator relative to the carriage in a focusing direction so that movement produced by the plurality of focusing forces about the center of mass of the actuator is effectively absent, and forces reactive to the plurality of focusing forces are balanced and symmetric with respect to the optical axis to thereby produce only insubstantial movement about the center of mass of the actuator so that inertial forces acting on the actuator are balanced and symmetric about the optical axis.