Patent ID: 7751060
Filing Date: 2010-07-06
Classification: G03F

Abstract:
1. A position measuring system comprising: a measurement unit which includes a laser interferometer configured to measure a position of a measurement target by using interference of a laser beam; a wavelength detection unit configured to detect a wavelength change of the laser beam; a first compensation unit configured to compensate for the wavelength change detected by said wavelength detection unit on the basis of a phase difference of aerial vibration between said wavelength detection unit and an optical path of said laser interferometer, which is determined on the basis of a difference in length between a first path of the aerial vibration from an aerial vibration source of an air conditioner to said wavelength detection unit and a second path of the aerial vibration from the aerial vibration source to the optical path of said laser interferometer; and a second compensation unit configured to compensate for a measurement value obtained by said laser interferometer on the basis of the wavelength change compensated by said first compensation unit, wherein the first path is shorter than the second path.