Patent ID: 7084534

Claim:
An alignment stage apparatus including a base structure and a movable stage which can move along a surface of the base structure so as not to be in contact with the base structure, said apparatus comprising: a plurality of power transmission coils buried under the surface of the base structure; a power reception coil attached to the movable stage to oppose the surface; a switch unit configured to sequentially switch, of said plurality of power transmission coils, those that are to be energized to feed power in accordance with a position of the movable stage; and a power feed unit configured to supply AC power to said power transmission coils to be energized through said switch unit, wherein said power reception coil comprises a plurality of power reception coils arrayed in a driving direction of said movable stage, and said power reception coils and power transmission coils are phase-shifted from each other by 180°/n where n is the number of power reception coils arrayed in the driving direction of said movable stage.