Patent ID: 8786831

Claim:
A positioning apparatus comprising: a moving member including a magnet unit having a cyclic magnetic-flux-density distribution along a first direction parallel to a predetermined surface; a coil unit including a plurality of coils arranged in the first direction at a pitch according to the cyclic magnetic-flux-density distribution, the first direction being perpendicular to a longitudinal direction of the coils; and a controller configured to generate a supporting force for supporting a weight of the moving member using the coils and to generate a positioning force for positioning the moving member in the predetermined surface, wherein the controller is configured to generate curve-correcting forces f 1 and f 2 for correcting curving deformation caused by the moving member being moved in the first direction, the curve-correcting forces f 1 and f 2 being different from the positioning force using the coils, and the forces f 1 and f 2 have same magnitudes and opposite directions, and a force line of the force f 1 corresponds to a force line of the force f 2 in the predetermined surface.