| 摘要 |
Position information within a moving plane of a stage (WST) is measured by using three encoders including at least an X encoder and a Y encoder. Based on the position measurement value of the stage (WST), the encoders to be used for position measurement are switched from encoders (Enc1, Enc2 and Enc3) to encoders (Enc4, Enc2 and Enc3). At the time of switching, a coordinate connecting method or a phase connecting method is applied, and an initial value of the encoder (Enc4) to be newly used is set. Thus, irrespective of sequential switching of the encoders to be used for position measurement of the stage (WST), the stage position measurement values are stored before and after switching, and the stage is accurately two-dimensionally driven. |
