Patent Document ID: 4794647
Application ID: 06721016
Patent Flag: 1

Claim One:
1. Apparatus for inspecting a patterned article, comprising: (i) image acquisition means for acquiring an image of at least part of said article and providing a binary signal, each bit of such binary signal representing a picture element of said image; (ii) storage means for storing bits of said binary signal, temporarily and successively; (iii) first means responsive to said storage means for determining the binary state of a first set of bits stored in said storage means, such first set corresponding, in said image, to at least one pair of picture elements that are spaced apart by a distance equivalent to the required spacing between successive edges between contrasting areas of the pattern on said article; (iv) dimensional verification means responsive to said first means for providing, in dependence upon the state of said pair of bits, a dimensional verification signal indicating whether or not said pair of picture elements are the required distance apart; (v) second means responsive to the storage means for determining, at the same instant, the state of a second set of bits corresponding, in said image, to a predetermined array of picture elements; (vi) pattern recognition means comprising edge detection means for determining whether or not said predetermined array of picture elements straddles an edge between contrasting areas of said pattern; means for storing a plurality of templates, each comprising an array of elements that represents an acceptable contour for such edge between contrasting areas, and means for comparing said second set of bits with said templates, said means for comparing being activated only upon detection of an edge by said edge detection means; said means for comparing providing a pattern recognition signal indicating whether or not the pattern formed by said array of picture elements, at a particular instant, corresponds to an acceptable edge profile; and (vii) output means responsive to said dimensional verification signal and said pattern recognition signal, for providing an output signal.