WOLFGANG KAUFMAN
Engineering in North Hampton, MA

4760444, Jul 26, 1988

Jul 22, 1987

7/076391

Paul C. Nielson - N. Andover MA
Wolfgang Kaufman - Northampton MA

CSD International, Inc. - Shelburne Falls MA

H04N 718

358101

A visual inspection device is disclosed in which a workpiece to be inspected is set onto a holding fixture in a defined position, the holding fixture having a fixed, crosshair target in a defined location on the fixture. The fixture is transported into one or more consecutive illuminated video scanned inspection fields having prepositioned therein a calibrated gray scale. The piece is then viewed for inspection by a video camera as an addressed data stream containing reflectance values and transmitted to a digitizer and a central processing unit. The inspection field of the data stream is shifted algorithmically such that the target is brought into alignment with and matches a target contained in a reference stream in memory. The data stream is further corrected algorithmically for ambient light by comparing the gray scale reflectance values in the inspection field to a reference gray scale in memory which has not been affected by ambient light. Variations in values cause rejection.