Patent ID: 8390780
Filing Date: 2013-03-05
Classification: G01D,G03F

Abstract:
1. A movable-body apparatus, comprising: a movable body that moves at least in an axis direction within a two-dimensional plane including a first axis and a second axis orthogonal to each other; and a measuring device that has a light source which irradiates a light onto a first grating arranged on a predetermined plane of the movable body, the predetermined plane crossing the two-dimensional plane, an optical system which allows a plurality of diffracted lights generated from the first grating to interfere with each other, and a detector which detects the interfered light, and that measures positional information of the movable body with respect to at least the axis direction, wherein the optical system has a second grating composed of a transmissive grating, and an optical member that changes directions of the plurality of diffracted lights generated at the first grating toward the second grating, and the detector detects the interfered light of the plurality of diffracted lights emitted from the second grating.