Patent ID: 6204918
Filing Date: 2001-03-20
Classification: G01N

Abstract:
An apparatus for surface inspection comprising:a light source;an irradiating optical system for directing an irradiating light beam from said light source onto a surface of an object under inspection;a light receiving optical system for receiving a scattered light beam reflected from the surface of said object under inspection;a photosensing portion for forming a surface data signal from the scattered light beam received by said light receiving optical system;a displacement portion for continuously displacing a surface of said object under inspection, relative to said irradiating optical system and said light receiving optical system, in main and sub-scanning directions; anda foreign matter detecting portion for detecting foreign matter present on the surface of said object under inspection on a basis of a maximum value level of said surface data signal and measuring the position, in the sub-scanning direction, of the foreign matter present on the surface of said object under inspection on the basis of each levels of at least two adjoining surface data signals in the sub-scanning direction.