Apparatus for web defect detection including a web swatch that contains a defect
Patent 3970857 Issued on July 20, 1976. Estimated Expiration Date: 
July 20, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 20, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3061731 3646353 3843890 InventorAssigneeApplicationNo. 602466 filed on 08/06/1975US Classes:250/559.1, With calibration250/559.45, With defect discrimination circuitry356/431Including transverse scanningExaminersPrimary: Smith, Alfred E.Assistant: Nelms, David C. AbstractAn improved web scanning inspection system that includes a fixed standard web swatch containing representative objectionable defects in the path of the scan beam at the onset of each scan in order to calibrate inspection system discriminator thresholds. Gating and logic circuits are arranged to extract amplitude and duration characteristics of the defect related portions of the signals generated by scans across the standard swatch material. These are then used to actuate an alarm whenever the inspection system discriminator circuits fail to detect the objectional defects in the standard web swatch.Field of SearchSpecial photocell or electron tube circuits | |
