Patent ID: 8440971
Filing Date: 2013-05-14
Classification: G01N

Abstract:
1. An apparatus for examining an object whose thickness is unknown, comprising: an irradiating portion for irradiating an object with radiation; a detecting portion for detecting radiation from the irradiated object; an acquiring portion for acquiring transmission time of the radiation from the irradiating portion, which is associated with detection time of the radiation detected by the detecting portion, and amplitude of the radiation detected by the detecting portion; a storing portion for beforehand storing relationship data between the transmission time and amplitude, and representative values of characteristic of the object; and a calculating portion for obtaining values of thickness and characteristic of the object based on the transmission time, the amplitude and the relationship data stored in the storing portion, wherein the representative values of characteristic of the object are values of a complex refractive index or a characteristic of the object capable of being derived from the complex refractive index, and wherein the calculating portion simultaneously obtains the values of thickness and characteristic of the object by converging the value of the thickness of the object so that the values of the complex refractive index or the calculated characteristic of the object are fitted to the relationship data.