Photoelectric inspection apparatus for material having variations in reflectivity

Claim 1

AN INSPECTION SYSTEM FOR DISCRETE PIECES OF MATERIAL HAVING PREDETERMINED SPACINGS DEFINING SUCCESSIVE GAPS AND HAVING A FIRST NORMAL REFLECTIVITY VALVE AND SECOND ABNORMAL REFLECTIVITY VALVE, SAID ABNORMAL REFLECTIVITY VALVE DUE TO IMPERFECTIONS IN THE PIECES OF MATERIAL IN THE FORM OF HOLES AND STAINS, SAID SYSTEM INCLUDING: CONVEYOR MEANS EFFECTIVE TO MOVE SAID PIECES ALONG A PREDETERMINED PATH AND TO RECEIVE SAID PIECES IN SPACED RELATION ALONG SAID PATH, SAID PIECES HAVING VARYING ORIENTATIONS AND EDGE SHAPES; MEANS EFFECTIVE TO SCAN SUCCESSIVE AREAS OF SAID PIECES OF MATERIAL IN A PATH OF SCAN AS THEY PASS BENEATH SAID SCAN MEANS ON SAID CONVEYOR MEANS, SAID PATH OF SCAN BEING A SUBSTANTIALLY STRAIGHT LINE WITH A SUBSTANTIAL DEVIATION FROM THE NORMAL TO SAID PREDETERMINED PATH, THE DEVIATION OF SAID PATH OF SCAN FROM THE NORMAL BEING SUCH THAT AT LEAST ONE SCAN CAN BE MADE WITHIN THE CONFINES OF EACH OF SAID GAPS; MEANS EFFECTIVE TO PRODUCE SIGNALS INSTANTANEOUSLY RESPONSIVE TO LIGHT REFLECTED FROM SAID MATERIAL DURING THE COURSE OF A SINGLE SCAN; FIRST STORAGE MEANS EFFECTIVE TO INTEGRATE SAID SIGNALS DURING A SINGLE SCAN TO THE EXTENT THAT SAID SIGNALS ARE A RESPONSE TO SAID ABNORMAL REFLECTIVITY, SECOND STORAGE MEANS EFFECTIVE TO INTEGRATE THE SIGNALS FROM SAID FIRST STORAGE MEANS OVER A PLURALITY OF SCANS; MEANS OPERATIVE IN RESPONSE TO A COMPLETION OF SCAN HAVING AT LEAST A PORTION OF ITS TRAVEL WITH SAID NORMAL REFLECTIVITY TO TRANSFER SIGNALS FROM SAID FIRST STORAGE MEANS TO SAID SECOND STORAGE MEANS AND IN RESPONSE TO A SCAN WITHOUT AT LEAST A PORTION OF ITS TRAVEL WITH SAID NORMAL REFLECTIVITY TO DISCHARGE SAID SECOND STORAGE MEANS; AND ELEMENTS RESPONSIVE TO THE REFLECTIVITY OF THE CONVEYOR MEANS AND PIECES ALONG THE PATH OF SCAN WHEREBY IRREGULAR EDGES OF VARYING ORIENTATIONS OF THE PIECES WITH RESPECT TO THE CONVEYOR MEANS WILL NOT EFFECT THE OPERATION OF THE INSPECTION SYSTEM.