Patent Document ID: 5557690
Application ID: 08265979
Patent Status: 1

Claim One:
1. An apparatus for locating an object on a substrate, the object, from the perspective of an input device, having at least one substantially straight edge, said apparatus comprising: said input device for capturing an image of at least a portion of said substantially straight edge, and for creating a sampling window comprising an array of image elements which are arranged in a plurality of substantially parallel rows; a device that orients said substrate with respect to said input device such that an image of said substantially straight edge of said object and at least one of said rows intersect at an angle that is both predetermined and oblique; a circuit that determines as edge image elements a number of said image elements which define said substantially straight edge for use in determining the precise location of said object on said substrate, said number being determined using a trigonometric function of said angle such that said number is approximately an integral multiple of the number of edge image elements that are in a row of said sampling window; and a circuit that precisely locates said object on said substrate based on the relative positions of said number of edge elements.