Position-control stage with onboard linear motor

Abstract

A position-control stage is disclosed which makes it possible to extend largely an angular movement in circular direction for position control, rendering the stage itself compact in construction, allowing to work with high precision in clean environment and further produce the stage with inexpensive cost. The position-control stage has an onboard linear motor composed of armature windings of primary side and field magnets of secondary side. The armature windings are each made in a hollow rectangle where winding turns are wound in the form of flat loop, and are circularly arranged on a disc surface of the bed along a preselected curvature in such a way lying in radial juxtaposition in circumferential direction. The field magnets are made in a flat shape and arranged underneath the turntable in such a pattern lying radially on a disc surface of the preselected curvature in opposition to the armature windings, with their unlike poles alternating in polarity along a circular direction.