INSPECTION METHOD AND APPARATUS FOR DETECTING OVERSIZED APERTURES IN RELATIVELY THIN SHEETS OF OPAQUE MATERIAL

摘要

An inspection method and apparatus for detecting oversized apertures in thin sheets of opaque material utilizing a light source positioned in an encasement means having a floor and a plurality of upstanding walls about the perimeter of the floor. Each of these walls has a ledge formed thereon for supporting a translucent enclosure member having a predetermined pattern of openings spaced therein. As a relatively thin sheet of apertured material is positioned on the surface of the enclosure member according to alignment pins on the surface, a comparator means, hingedly affixed to one side of the enclosure member and comprising a relatively thin sheet of transparent material having an opaque pattern formed thereon corresponding to the aperture pattern desired for the opaque material, is lowered to cover the opaque material. Oversized apertures are detected if light is emitted through the adjoining comparator means and opaque material.