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US 5,854,683 AGranted
Optical web defect detection system
OwnerBarry P. Keaneinventor
Life of this patent
Estimating the term…
Abstract
An optical web defect detection system includes a light source and a detector disposed with respect to the light source so that the detector receives light modulated by a web moving proximate the light source. The detector outputs a signal corresponding to the modulated light. An adjustment mechanism is in operative communication with the detector to adjust the position of the detector with respect to the web. A control mechanism is in operative communication with the detector and the adjustment mechanism. The control mechanism receives the signal to detect a defect in the web based thereon and adjusts the position of the detector to optimize reception of the modulated light by the detector.
Claims37
An optical web defect detection system, said system comprising:
- a light source;
- a detector disposed with respect to said light source so that said detector receives light modulated by a moving web proximate said light source, wherein said detector outputs a signal corresponding at least in part to said modulated light;
- an adjustment mechanism in operative communication with said detector to adjust the position of said detector with respect to said web;
- and
- a control mechanism in operative communication with said detector and said adjustment mechanism, said control mechanism receiving said signal to detect a defect in said web based thereon and adjusting said position of said detector to optimize reception of said modulated light by said detector.
2 more elements
An optical web defect detection system, said system comprising:
- a light source;
- a plurality of detectors disposed proximate to each other to extend across the path of travel of a moving web, each said detector having an elongated optical sensor disposed so that said sensor receives light modulated by said web moving between said detector and said light source, wherein each said detector outputs a signal at least in part corresponding to said modulated light received by its said sensor;
- an adjustment mechanism in operative communication with said detector to adjust the position of said detector with respect to said web;
- and
- a control mechanism in operative communication with said detector and said adjustment mechanism, said control mechanism being configured to adjust, in conjunction with said adjustment mechanism, said position of each said detector to align its said sensor with elements of said web to maximize reception of said modulated light by said sensor, and including
- a gain stage receiving said signals from said plurality of detectors and having at least one adjustable gain device,
- at least one processor that adjusts said at least one adjustable gain device so that said signals are amplified to a predetermined level, and
- a comparator stage that compares each said amplified signal to at least one reference signal,
- wherein said at least one processor detects a defect in said web based on said comparison by said comparator stage.
6 more elements
An optical web defect detection system, said system comprising:
- a light source;
- a plurality of detectors disposed proximate to each other to extend across the path of travel of a moving web, each said detector having an elongated optical sensor disposed so that said sensor receives light modulated by said web moving between said detector and said light source, wherein each said detector outputs a signal corresponding at least in part to said modulated light received by its said sensor;
- an adjustment mechanism in operative communication with said detector to adjust the position of said detector with respect to said web;
- a control mechanism in operative communication with said detector and said adjustment mechanism, said control mechanism being configured to selectively adjust, in conjunction with said adjustment mechanism, said position of each said detector
- to a transverse position in which its said elongated optical sensor is aligned transversely to said path of travel of said web so that said optical sensors of said plurality of detectors receive said modulated light from an area of said web extending substantially across said web, and
- to a longitudinal position in which its said elongated optical sensor is aligned longitudinally to said path of travel of said web,
- wherein said control mechanism is also configured to adjust, in conjunction with said adjustment mechanism, said position of each said detector in either of said transverse position and said longitudinal position to align its said sensor with elements of said web to maximize reception of said modulated light by said sensor,
- wherein said control mechanism includes
- a gain stage having a plurality of adjustable gain devices, each said adjustable gain device receiving said signal from a respective one of said detectors,
- at least one processor that adjusts each said adjustable gain device so that said signal received by said adjustable gain device is amplified to a predetermined level, and
- a comparator stage receiving said amplified signal from each said adjustable gain device, said comparator stage including
- a plurality of first comparators, each said first comparator receiving said amplified signal from a respective said adjustable gain device and comparing said amplified signal to a positive said reference signal so that said first comparator changes state when said amplified signal exceeds said positive reference signal, and
- a plurality of second comparators, each said second comparator receiving said amplified signal from a respective said adjustable gain device and comparing said amplified signal to a negative said reference signal so that said second comparator changes state when said amplified signal drops below said negative reference signal, and
- wherein said at least one processor detects a defect in said web based on whether one or more of said first comparators and said second comparators change state;
- a shift mechanism in communication with said plurality of detectors and said control mechanism and configured to reciprocally move said detectors a predetermined distance transverse to said path of travel of said web when said detectors are in said longitudinal position so that said plurality of detectors receives said modulated light from an area of said web extending substantially across said web;
- and
- an alarm mechanism in operative communication with said control mechanism and configured to notify an operator responsive to said control mechanism upon detection of a said defect.
14 more elements
A system for handling and inspecting a web of indeterminate length, said system comprising:
- a frame configured to secure said web and move said web along a path of travel;
- a light source disposed on said frame;
- a detector disposed on said frame with respect to said light source so that said detector receives light modulated by a moving web proximate said light source, wherein said detector outputs a signal corresponding at least in part to said modulated light;
- an adjustment mechanism in operative communication with said detector to adjust the position of said detector with respect to said web;
- and
- a control mechanism in operative communication with said detector and said adjustment mechanism, said control mechanism receiving said signal to detect a defect in said web based thereon and adjusting said position of said detector to optimize reception of said modulated light by said detector.
3 more elements
A method for optically detecting defects in a moving web, said method comprising:
- moving a web proximate a light source;
- receiving light by a detector disposed proximate said light source so that said detector receives light modulated by said moving web;
- outputting a signal from said detector to a control mechanism so that said signal corresponds at least in part to said modulated light;
- detecting defects in said web based on said signal;
- and
- controlling, by said control mechanism, the position of said detector based on said signal to optimize reception of said modulated light by said detector.
3 more elements
Dependencies are inferred from the claim text.