| 摘要 |
Positional information of a stage within a movement plane is measured, using three encoders which include at least one each of an X encoder and a Y encoder. Based on position measurement values of the stage, the encoder used in position measurement is switched from an encoder (Enc1, Enc2 and Enc3) to an encoder (Enc4, Enc2 and Enc3). On the switching, a coordinate linkage method or a phase linkage method is applied to set an initial value of an encoder (Enc4) which is to be newly used. Accordingly, position measurement values of the stage before and after the switching are stored even though the encoder used in position measurement of the stage is sequentially switched, and the stage can be driven accurately two-dimensionally.
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