Patent ID: 6566671
Filing Date: 2003-05-20
Classification: G01N

Abstract:
An apparatus for inspecting defects of a sample, comprising:a video signal detection portion for outputting a video signal in synchronism with a first frequency upon picking up an image of a sample; an A/D converter portion for outputting detection video data through A/D conversion of the video signal outputted from the video signal detection portion; a reference video production circuit portion for producing reference video data to be compared with the detection video data outputted from the A/D conversion portion; a position gap detection circuit portion for detecting position gaps between the detection video data outputted from the A/D converter portion and the reference video data outputted from the reference video production circuit portion, to perform correction thereof in synchronism with a second frequency which is greater than the first frequency; and a comparison circuit portion for comparing the detection video data, being corrected in position gaps thereof within the position gap detection portion, with the reference video data in synchronism with the second frequency, so as to obtain a pseudo-defect point, thereby to output information relating to the pseudo-defect point.