Stage device
First Claim
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1. A stage device comprising:
- a base;
a stage carrying a movable body and being moved over the base;
a planar motor driving the stage;
an air bearing acting to lift the stage over the base;
a scale part disposed on the base to include an angle grating which has an angle-related characteristic varied in a two-dimensional direction in accordance with a known function; and
at least one two-dimensional angle sensor disposed on the stage so that the at least one two-dimensional angle sensor emits a light beam to the angle grating of the scale part and detects a two-dimensional angle of a light beam reflected from the scale part.
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Abstract
This invention relates to a stage device which is moved with high accuracy in an X-Y direction and a rotating direction using a planar motor. The invention is aimed at reducing the size of the stage device and at performing accurately measurement of a position of the stage to the base. The stage device comprises a scale unit having a scale part on the entire plane of the base, and three two-dimensional angle sensors disposed on a bottom surface of a movable stage part. The scale unit and the two-dimensional angle sensors form a surface encode. A position of the movable stage part is measured by the surface encoder.
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Citations
6 Claims
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1. A stage device comprising:
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a base;
a stage carrying a movable body and being moved over the base;
a planar motor driving the stage;
an air bearing acting to lift the stage over the base;
a scale part disposed on the base to include an angle grating which has an angle-related characteristic varied in a two-dimensional direction in accordance with a known function; and
at least one two-dimensional angle sensor disposed on the stage so that the at least one two-dimensional angle sensor emits a light beam to the angle grating of the scale part and detects a two-dimensional angle of a light beam reflected from the scale part. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification