Linear motor apparatus
AssigneeCanon Kabushiki Kaisha
InventorMikio Sato
Life of this patent
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Abstract
A linear motor apparatus which drives a mover of a linear motor in a stable manner, by using only information on change of relative position, without using an absolute value sensor. The apparatus has a coil array of plural phases of coils and a magnet relatively movable to the coil array, plural drivers, at least one of which being provided for each phase, to feed a current to all the same phase coils of the coil array, a sensor for measuring a change of relative position of the magnet moved by the current to the coil array, and a controller to determine the polarity of the current applied to the same phase coils based on the change of the relative position measured by the sensor, and apply a drive current to drive the magnet in a desired direction to the same phase coils.
Claims8
A linear motor apparatus having a coil array of plural phases of coils and a magnet relatively movable to said coil array, comprising:
- plural drivers, at least one of which being provided for each phase, to feed a current to all the same phase coils of said coil array;
- measurement means for measuring a change of relative position of said magnet moved by said current to said coil array;
- and
- a controller to determine the polarity of the current applied to the same phase coils based on the change of the relative position measured by said measurement means, and apply a drive current to drive said magnet in a desired direction to the same phase coils.
A stage apparatus having:
- a movable unit;
- and
- a linear motor apparatus to drive said movable unit for positioning in a predetermined position,
- wherein said linear motor apparatus having a coil array of plural phases of coils and a magnet relatively movable to said coil array, comprising:
- plural drivers, at least one of which being provided for each phase, to feed a current to all the same phase coils of said coil array;
- measurement means for measuring a change of relative position of said magnet moved by said current to said coil array;
- and
- a controller to determine the polarity of the current applied to the same phase coils based on the change of the relative position measured by said measurement means, and apply a drive current to drive said magnet in a desired direction to the same phase coils.
An exposure apparatus having:
- a reticle stage holding a reticle, to drive the reticle to a predetermined position thereby positioning the reticle in a predetermined position;
- a substrate stage holding a substrate, to drive the substrate to a predetermined position thereby positioning the substrate in a predetermined position;
- a linear motor apparatus to drive said reticle stage and/or said substrate stage;
- and
- a projection optical system to project a pattern of said reticle on said substrate,
- wherein said linear motor apparatus, having a coil array of plural phases of coils and a magnet relatively movable to said coil array, comprising:
- plural drivers, at least one of which being provided for each phase, to feed a current to all the same phase coils of said coil array;
- measurement means for measuring a change of relative position of said magnet moved by said current to said coil array;
- and
- a controller to determine the polarity of the current applied to the same phase coils based on the change of the relative position measured by said measurement means, and apply a drive current to drive said magnet in a desired direction to the same phase coils.
Dependencies are inferred from the claim text.