摘要 |
During the drive of a stage, positional information in a movement plane of a stage is measured by three encoders that include at least one each of an X encoder and a Y encoder of an encoder system, and a controller switches an encoder used for a measurement of positional information of a stage in the movement plane from an encoder to an encoder so that the position of the stage in the movement plane is maintained before and after the switching. Therefore, although the switching of the encoder used for controlling the position of the stage is performed, the position of the stage in the movement plane is maintained before and after the switching, and a correct linkage becomes possible. |