Patent Document ID: 4776022
Application ID: 06721477
Patent Status: 1

Claim One:
1. Apparatus for inspecting and determining the presence of defects in features of patterned images of lines and spaces of predetermined acceptable line width and spacing sizes comprising: (a) an array of detectors for forming a pixel window consisting of a plurality of pixel bits of one of two possible opposite states generated by a characteristic of the image viewed by said detectors; (b) matrix apparatus for forming said pixels in a matrix of bits available for selection; (c) a first pattern of pixel bits selected from said matrix forming an enable pattern for determining if the feature viewed generates a first state bit signal or an opposite state bit signal; (d) a set of second patterns of pixel bits selected from said matrix forming progressively larger patterns about the center of the window for determining an edge of the feature by examining the state of all pixel bits in said set of second patterns until a pattern is found in which all pixel bits are not in the same state; (e) a set of third patterns selected from said matrix forming a series of verification patterns, one such verification pattern in the series being selected depending upon which one of the second patterns was the first second pattern in which all pixel bits were not in the same state; (f) logic means for determining the nature of the feature by examining the selected verification pattern to count the number of certain predetermined pixel bits of the verification pattern.