Patent ID: 6434264
Filing Date: 2002-08-13
Classification: G01N,G01R,G06T,H05K

Abstract:
In a printed circuit assembly production line having a plurality of component processing locations and a conveyor system for transporting circuit assemblies between processing locations in an upstream to downstream work flow direction, a vision comparison inspection system, comprising:a printed circuit assembly image capture and inspection conveyor disposed in said production line, said image capture and inspection conveyor being adapted to receive printed circuit assemblies from an upstream portion of said production line and to transport said printed circuit assemblies to a downstream portion of said production line for subsequent processing; an electronic imaging device fixedly positioned to capture an image of a printed circuit assembly positioned at an image capture location on said image capture and inspection conveyor; a lighting system for illuminating the printed circuit assembly at said image capture location; a position control system for positioning the printed circuit assembly at said image capture location; an imaging control system including a programmed image processing computer, an input device and an electronic display device for alternatingly displaying on said display device a stored image of a known good printed circuit assembly and an image of a printed circuit assembly under test, whereby defects in said printed circuit assembly under test can be visually identified; and wherein said position control system includes a movable pin, said pin being extendable into the path of an oncoming printed circuit assembly and defining a first reference surface to stop said assembly for imaging at said image capture location, and at least one side clamp for clamping at least one side of said printed circuit assembly against a second reference surface, said first and second reference surfaces cooperating with respective edges of said printed circuit assembly to define a reference point which is the corner of said printed circuit assembly defined by the intersection of said respective edges, said reference point being the same regardless of the size of said printed circuit assembly, and said first and second reference surfaces further cooperating to align said printed circuit assembly in a fixed orthogonal orientation, said pin and said at least one side clamp being retractable when inspection of said assembly has completed.