| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform stable and highly accurate drive control of a movable body. <P>SOLUTION: When an irradiation point of a measurement beam of an encoder head is positioned in an area other than temporarily stopping areas (SU<SB>1</SB>, SU<SB>2</SB>) on a scale 39Y<SB>1</SB>, positional information obtained from the head is corrected to avoid generation of a measurement error. When the irradiation point is positioned outside the scale or in the temporarily stopping areas (SU<SB>1</SB>, SU<SB>2</SB>), the correction of the positional information is stopped. Here, for example, an end of the scale, an area where a diffraction grating formed on the scale is damaged, an area where the diffraction grating is distorted, an area where foreign matter is attached, a vicinity of a positioning pattern or the like are selected as the temporarily stopping areas on the scale 39Y<SB>1</SB>, so that an unstable operation of the head is avoided and a stable operation of an encoder system is performed, thereby a stable drive control of a wafer stage is performed. <P>COPYRIGHT: (C)2010,JPO&INPIT |
