Patent US3783296A successfully refreshed from Google Patents.
US3783296A
Expired / Lapsed
US
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Method and apparatus for detecting flaws in a fabric web
Assignee: Milliken Research Corp
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Filing: 1972-04-14
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Granted: 1974-01-01
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Expires: 1992-04-14
Abstract
Abstract A method and apparatus to inspect and detect deviations in a repetitive mesh pattern from a predetermined norm for the particular mesh pattern wherein a highly collimated monochromatic light beam, such as a laser beam, is directed to pass through the mesh pattern, such as a woven or knitted fabric, is diffracted by the mesh pattern, and the diffracted laser pattern is directed onto a mask which is indicative of a norm for the mesh pattern. A light-detecting apparatus, such as a photocell, is placed beyond the mask and any deviation in the mesh of the fabric from a predetermined norm for that particular fabric results in a deviation of the diffracted pattern of the laser beam through the mask which affects, and is detected by, the photocell.
Inventors
- 👤 M Blevins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:57
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N33/00; G01N33/36
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
189 words
In an apparatus to detect flaws in a web of material, the combination of, a highly collimated substantially monochromatic light source positioned to be incident on said web of material and to be diffracted by said web of material as said light passes therethrough, means to detect deviations of the diffracted light pattern including a mask comprising a light transparent plate having impressed thereon a mask pattern which correlates with the diffracted light pattern of a web of said material known to have no flaws and light detecting means below said mask adapted to detect variations in light intensity passing through said mask whereby when said light beam passes through a flawless web of said material, the diffracted light pattern will correlate with the light pattern exposed on said mask and when said light beam passes through a flaw in the web of said material, the diffraction pattern will deviate from the pattern exposed on said mask to alter the intensity of light passing therethrough to the light detecting means which detects the change in light intensity to indicate the presence of a flaw in said web of material.
Claim 2
Dependent Claim
189 words
In an apparatus to detect flaws in a web of material, the combination of, a highly collimated substantially monochromatic light source positioned to be incident on said web of material and to be diffracted by said web of material as said light passes therethrough, means to detect deviations of the diffracted light pattern including a mask comprising a light transparent plate having impressed thereon a mask pattern which correlates with the diffracted light pattern of a web of said material known to have no flaws and light detecting means below said mask adapted to detect variations in light intensity passing through said mask whereby when said light beam passes through a flawless web of said material, the diffracted light pattern will correlate with the light pattern exposed on said mask and when said light beam passes through a flaw in the web of said material, the diffraction pattern will deviate from the pattern exposed on said mask to alter the intensity of light passing therethrough to the light detecting means which detects the change in light intensity to indicate the presence of a flaw in said web of material.
Claim 3
Dependent Claim
32 words
Apparatus as defined in claim 1 wherein said web of material is adapted to move with respect to said apparatus to detect flaws while flaws are detected in said web of material.
References Cited (Backward Citations)
US3169193A
Cited
US3308658A
Cited
US3623815A
Cited
US3614232A
Cited
US3633037A
Cited
US3657727A
Cited
US3652864A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |