Abstract: A wiring pattern inspection apparatus for inspecting an abnormality of a wiring pattern formed on a printed circuit board, which is equipped with an optical image pickup device for optically illuminating a surface of the printed circuit board including the wiring pattern to photoelectrically convert optical information of the printed circuit board surface due to the optical illumination into a grey level image. This grey level image is converted into a bi-level image which separates the grey level image into the wiring pattern side and a background side of the wiring pattern. Thereafter, the bi-level image is once contracted by a first size and then expanded by a second size so as to eliminate a micro conductive portion left on the printed circuit board or a micro pinhole which can be disregarded in the abnormality inspection, thereby preventing the excessive detection.

Abstract: A wiring pattern inspection apparatus for inspecting an abnormality of a wiring pattern formed on a printed circuit board, which is equipped with an optical image pickup device for optically illuminating a surface of the printed circuit board including the wiring pattern to photoelectrically convert optical information of the printed circuit board surface due to the optical illumination into a grey level image. This grey level image is converted into a bi-level image which separates the grey level image into the wiring pattern side and a background side of the wiring pattern. Thereafter, the bi-level image is once contracted by a first size and then expanded by a second size so as to eliminate a micro conductive portion left on the printed circuit board or a micro pinhole which can be disregarded in the abnormality inspection, thereby preventing the excessive detection.