Patent ID: 8860925
Filing Date: 2014-10-14
Classification: G03F,Y10T

Abstract:
1. A movable body drive method in which a movable body is driven substantially parallel to a predetermined plane that is perpendicular to an optical axis, the method comprising: a drive process in which positional information of the movable body in a direction parallel to the plane is measured using an encoder system that includes a head which irradiates a measurement beam on a scale having a grating substantially parallel to the plane and receives a beam from the grating, and the movable body is driven parallel to the plane, based on the positional information and correction information of a measurement error of the encoder system relating to a position of the movable body in the direction parallel to the plane, the measurement error corresponding to an angle of inclination of the movable body with respect to the plane and occurring due to a difference of position of a surface of the scale in a direction perpendicular to the plane with respect to a reference surface serving as a reference for position control of the movable body.