Patent ID: 8675171
Filing Date: 2014-03-18
Classification: G03F

Abstract:
1. A movable body drive system that drives a movable body along a predetermined plane, the system comprising: an encoder system that has a plurality of heads that each irradiates a detection beam to a scale, the scale being parallel to the predetermined plane and having a grating, and receives a reflected beam from the scale, the encoder system measuring first position information of the movable body in a predetermined direction using one or more heads of the plurality of heads; and a drive system that drives the movable body in the predetermined direction based on the first position information and correction information of a measurement error of the encoder system, the measurement error of the encoder system being caused by a relative motion of the head and the scale in a direction different from the predetermined direction, wherein second position information of the movable body that shows the relative motion is measured at the time of the measurement of the first position information, wherein the one or more heads used in the measurement of the first position information are at least partially switched to another head of the plurality of heads according to movement of the movable body in the predetermined plane.