Patent ID: 6584420
Filing Date: 2003-06-24
Classification: G06K,G06T

Abstract:
A defect examination apparatus for detecting defect locations of a plurality of to-be-inspected objects vertically and horizontally arranged according to a prescribed rule, comprising:blob analysis means for finding location coordinates of the plurality of to-be-inspected objects; rotation angle calculation means for finding a rotation angle for a horizontal series of the plurality of to-be-inspected objects against a horizontal line and a rotation angle for a vertical series of the plurality of to-be-inspected objects against a vertical line based on a location coordinate found by the blob analysis means, the rotation angle calculation means finding an optimal rotation angle by using a frequency distribution found by projecting and accumulating to-be-inspected objects' location coordinates onto a prescribed projection axis; pitch size calculation means for finding vertical and horizontal pitch sizes of the plurality of to-be-inspected objects from distances between adjacent peak locations of frequency distributions corresponding to respective rows and columns; and matrix number analysis means for finding a matrix number for each to-be-inspected object based on a rotation angle found by the rotation angle calculation means and a pitch size found by the pitch size calculation means.