Patent ID: 8203697

Claim:
A movable body drive method in which a movable body is driven within a moving plane including first and second axes that are orthogonal to each other, the method including: a first moving process of moving the movable body in a direction parallel to the first axis, based on a measurement value of a first interferometer that measures position information of the movable body in a direction parallel to the second axis by irradiating a measurement beam to a reflection surface arranged on the movable body, and a measurement value of a second interferometer that measures position information of the movable body in a direction parallel to the first axis by irradiating a second measurement beam to a second reflection surface arranged on the movable body; a process of deciding correction information of grating pitch of a scale that is sequentially placed facing a head unit according to the movement of the movable body in the first moving process, based on a measurement value of the second interferometer, a measurement value of an encoder and information on flatness of the scale, the head unit constituting the encoder that measures position information of the movable body in a direction parallel to the first axis based on a measurement value of a head that faces the scale arranged on the movable body having a grating in a predetermined pitch whose periodic direction is the direction parallel to the first axis, and including a plurality of the heads that are placed at a predetermined distance along a direction parallel to the second axis; and a process of driving the movable body in a direction parallel to the first axis, while correcting a measurement value obtained from the head unit based on the correction information of grating pitch.