Patent ID: 7161267

Claim:
A displacement apparatus, comprising: a first part comprising a first coil system that includes a first plurality of windings having a longitudinal axis extending along a first direction and a second coil system that includes a second plurality of windings having a longitudinal axis extending along a second direction, wherein said first and second directions lie in a plane and said first and second plurality of windings configured to respectively carry a current; a second part comprising a conductive platen disposed in a vicinity of said first part in a zone in which said first and second coil systems induce a magnetic field in said platen based on the currents carried by said first and second plurality of windings; and an alternating current supply configured to supply a multi-phase alternating current to said first and second coil systems, wherein a phase difference between the magnetic field of said first and second plurality of windings and the magnetic field induced in said platen subjects said first and second parts to a force resulting in said first and second parts being displaceable relative to one another along said second and first directions, respectively, and in a third direction that is at an angle to said plane.