Patent ID: 6141300
Filing Date: 2000-10-31
Classification: G11B,H02K

Abstract:
An apparatus for controlling the position of a lens, said apparatus comprising:a suspended body having a center of mass and a lens defining an optical axis, said center of mass being disposed substantially on said optical axis;a carriage having a center of mass, said carriage for suspending said suspended body at an initial position relative to said carriage for relative motion thereto with at least one degree of freedom, said center of mass of said carriage lying substantially on said optical axis proximate said center of mass of said suspended body, and said carriage having an initial attitude with respect to three mutually orthogonal planes of reference defined by an X axis, a Y axis, and a Z axis, so that suspensory forces acting on said suspended body are thereby symmetric about said optical axis; anda first drive for said carriage, said first drive producing a first plurality of forces that are balanced and symmetric about said optical axis to accelerate said carriage and said suspended body therewith along said Y axis so that moments produced by said first plurality of forces about said center of mass of said carriage are substantially absent and forces reactive to said first plurality of forces are balanced and symmetric with respect to said optical axis to thereby produce only insubstantial moments about said center of mass of said carriage so that inertial forces acting on said carriage are balanced and symmetric about said optical axis and said carriage maintains said attitude with respect to said planes of reference during acceleration thereof while said suspended body maintains a relative position with respect to said carriage.