Patent ID: 6346982
Filing Date: 2002-02-12
Classification: G01N

Abstract:
A device for examining flat workpieces having front and back sides, said device comprising a turntable having a transparent workpiece-carrying portion formed from a transparent hard material, a conveyor for carrying the workpieces with front or back side thereof in contact with the conveyor surface, a transfer mechanism for moving the workpieces being carried on said conveyor onto said workpiece-carrying portion of said turntable, a guide for guiding the workpieces on said turntable to an examination point on said turntable while said turntable is turning, a camera for photographing the workpieces one by one when they reach said examination point, an image sensor unit for determining whether each of the workpieces photographed by said camera is defective or nondefective, and a workpiece discharge unit for discharging the defective and non-defective workpieces out of said turntable separately from each other, said image sensor unit including a lighting unit, provided opposite said camera with said turntable between said camera and said lighting unit, operable to shed light through said transparent workpiece-carrying portion of said turntable on each workpiece at said examination point.