Patent ID: 8199332
Filing Date: 2012-06-12
Classification: G01B

Abstract:
1. An apparatus for measuring a thickness, comprising: a first beam splitter for reflecting or transmitting a ray irradiated from an optical source or a ray reflected by a measurement object to the measured; a first lens part which condenses a ray to the measurement object and generates a reference ray having a difference of a light path in comparison with a ray reflected by the measurement object; a second lens part for condensing a ray to the measurement object; an interference light detector which corresponds to the first lens part so as to form a light path and detects an interference signal generated by the ray reflected by the measurement object and the reference ray; a spectroscopic detector which corresponds to the second lens part so as to form a light path different from the light path formed by the interference light detector and splits the ray reflected by the measurement object so as to detect an intensity and a wavelength of each split ray; and a light path converter for selectively transmitting a ray to one of the interference light detector and the spectroscopic detector, wherein the light path converter includes a reflecting mirror, which reflects a ray to one of the interference light detector and the spectroscopic detector, and a mirror driving part which moves the reflecting mirror so as to allow the reflecting mirror to be positioned at a light path or to be deviated from the light path, wherein position exchanging is performed between the first lens part and the second lens part.