A method of and apparatus for comparing the location of an extended feature within a field of view with a standard location

摘要

Method of, and apparatus for, comparing the location of an extended feature within a field of view with a standard location. The field of view is scanned to obtain a binary video signal representing the feature, the signal is processed to give a single feature position pulse when scanning of the feature has been completed, the scan co-ordinates of the feature position pulse are determined, and the co-ordinates are compared with those corresponding to the standard location. The area of the feature may also be determined. The method is applicable to the checking of printed circuit boards.