Alignment stage apparatus
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. The apparatus includes 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 the 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 the power transmission coils to be energized through the switch unit. The power reception coil includes a plurality of power reception coils arrayed in a driving direction of the movable stage, and the 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 the movable stage.
1. 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.
2. 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 feeding unit configured to supply AC power to said power transmission coils to be energized through said switch unit,
wherein a frequency of the AC power is set at a resonance frequency determined by a load and a mutual inductance of said power transmission coils and said power reception coil.