US3841761A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting faults in fabric
Assignee: NEOTEC Corp A CORP OF DE
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Filing: 1973-10-24
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Granted: 1974-10-15
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Expires: 1993-10-24
Abstract
Abstract A sensor housing is located adjacent a moving sheet of fabric. A number of adjacent inspection channels along the length of the fabric are defined, each channel being subject to fabric flaw detection by three sensors located within the housing. A single lamp in the housing serves as a light source for all sensors. A first sensor detects changes in fabric reflectance. A second sensor detects changes in fabric transmittance. A third sensor detects texture variations by responding to obstructions to light directed at grazing incidence to the fabric. Circuitry is connected to the output of the sensors for weighing the individual signals, from the sensors, and summing the results. Should the summed signals exceed a preselected threshold value, an indication is generated which corresponds to the severity of the visual-tactile flaw as detected.
Inventors
- 👤 P Selgin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:37
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/89; G01N21/892; G01N21/898; G01N21/8983
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
198 words
A method for detecting color and textural defects in a sheet of moving material comprising the following steps: subjecting a preselected inspection area of the sheet to transmitted light incident to the sheet in a direction substantially perpendicular to the sheet; detecting the light passing through the preselected area of the sheet which varies according to excessive thinness or thickness of the material in the area and producing a first corresponding detection signal; subjecting the preselected area of the sheet to light at an acute angle of incidence for causing the reflection of light from the area; detecting the reflected light which varies in response to color and textural faults in the area and producing a second corresponding detection signal; subjecting the preselected area of the sheet to light impinging at a grazing angle; detecting the grazing light which varies in response to textural obstructions present in the area and producing a third corresponding detection signal; individually integrating the first, second and third signals; and summing the first, second and third signals, simultaneously to produce an output signal corresponding to the color-tactile impact of one or more detected defects in the preselected area at a single time instant.
Claim 2
Independent Claim
198 words
A method for detecting color and textural defects in a sheet of moving material comprising the following steps: subjecting a preselected inspection area of the sheet to transmitted light incident to the sheet in a direction substantially perpendicular to the sheet; detecting the light passing through the preselected area of the sheet which varies according to excessive thinness or thickness of the material in the area and producing a first corresponding detection signal; subjecting the preselected area of the sheet to light at an acute angle of incidence for causing the reflection of light from the area; detecting the reflected light which varies in response to color and textural faults in the area and producing a second corresponding detection signal; subjecting the preselected area of the sheet to light impinging at a grazing angle; detecting the grazing light which varies in response to textural obstructions present in the area and producing a third corresponding detection signal; individually integrating the first, second and third signals; and summing the first, second and third signals, simultaneously to produce an output signal corresponding to the color-tactile impact of one or more detected defects in the preselected area at a single time instant.
Claim 3
Dependent Claim
30 words
The method of claim 1 together with the step of multiplying each detection signal by a separate weight factor prior to summing, thus ascribing relative importance between the detection signals.
Claim 4
Dependent Claim
37 words
The method of claim 2 together with the step of comparing the output signal after summing, with a reference corresponding to an acceptable color-tactile defect level, for generating an indication when the output signal exceeds the reference.
Claim 5
Independent Claim
163 words
A system for detecting flaws in moving sheet material, the system comprising: a housing located on one side of the sheet and having an open end positioned adjacent the moving sheet; at least one source located in the housing for directing light toward a preselected area of the sheet; first sensing means located on a side opposite the sheet for responding to light transmitted through the preselected area which varies in accordance with thin and thick spots in the area; second sensing means located within the housing and in proximity to the preselected area for detecting light reflected from the area which varies in accordance with color and textural variations appearing in the area; third sensing means located within the housing and in proximity to the preselected area for detecting light grazing along the preselected area which varies in accordance with textural obstructions appearing in the area; and means respectively connected to the sensing means for making individual detection signals available for utilization.
Claim 6
Independent Claim
163 words
A system for detecting flaws in moving sheet material, the system comprising: a housing located on one side of the sheet and having an open end positioned adjacent the moving sheet; at least one source located in the housing for directing light toward a preselected area of the sheet; first sensing means located on a side opposite the sheet for responding to light transmitted through the preselected area which varies in accordance with thin and thick spots in the area; second sensing means located within the housing and in proximity to the preselected area for detecting light reflected from the area which varies in accordance with color and textural variations appearing in the area; third sensing means located within the housing and in proximity to the preselected area for detecting light grazing along the preselected area which varies in accordance with textural obstructions appearing in the area; and means respectively connected to the sensing means for making individual detection signals available for utilization.
Claim 7
Dependent Claim
62 words
The subject matter as set forth in claim 4 together with a separate amplifier connected to each connecting means for amplifying the detection signals; and circuit means connected to the amplifier for gating the detection signal to an output of the circuit means only when the detection signal exceeds a preselected threshold level, indicating a respective detected fault exceeding an acceptable limit.
Claim 8
Dependent Claim
58 words
The subject matter of claim 5 wherein a plurality of circuit means are provided for respective detection signals, and further wherein the outputs of the circuit means are cumulatively combined by utilization means for producing a signal indicative of the overall color-tactile impact of a fault or faults appearing in the area at a given instant of time.
Claim 9
Independent Claim
258 words
A system for detecting flaws in a moving fabric web, the system comprising: a plane for supporting the web, a preselected area in the plane defining an area where the fabric is inspected for faults, the area being divided into a plurality of adjacent channels; a housing located on one side of the web and having an open end positioned adjacent the inspection area; a plurality of identical photo-optical means consituting photo-optical inspection channels corresponding with the channels defined in the inspection area; each photo-optical channel including: a single source of light positioned in the housing; first sensing means located on an opposite side of the web for responding to light transmitted through the inspection area by the source, which varies in accordance with thick and thicn defect spots in the fabric as they appear in the area; second sensing means located within the housing and in proximity to the inspection station for detecting light reflected from the area which varies in accordance with color and textural variations of the fabric as they appear in the area; at least one interior portion of the housing having a reflective surface for reflecting light from the light source at a grazing incident angle to the inspection area; third sensing means located within the housing and in proximity to the preselected area for detecting the grazing light passing by the inspection area, the detected light varying in accordance with textural obstructions formed in the area; and means respectively connected to the sensing means for making individual detection signals available for utilization.
Claim 10
Independent Claim
258 words
A system for detecting flaws in a moving fabric web, the system comprising: a plane for supporting the web, a preselected area in the plane defining an area where the fabric is inspected for faults, the area being divided into a plurality of adjacent channels; a housing located on one side of the web and having an open end positioned adjacent the inspection area; a plurality of identical photo-optical means consituting photo-optical inspection channels corresponding with the channels defined in the inspection area; each photo-optical channel including: a single source of light positioned in the housing; first sensing means located on an opposite side of the web for responding to light transmitted through the inspection area by the source, which varies in accordance with thick and thicn defect spots in the fabric as they appear in the area; second sensing means located within the housing and in proximity to the inspection station for detecting light reflected from the area which varies in accordance with color and textural variations of the fabric as they appear in the area; at least one interior portion of the housing having a reflective surface for reflecting light from the light source at a grazing incident angle to the inspection area; third sensing means located within the housing and in proximity to the preselected area for detecting the grazing light passing by the inspection area, the detected light varying in accordance with textural obstructions formed in the area; and means respectively connected to the sensing means for making individual detection signals available for utilization.
Claim 11
Dependent Claim
59 words
The subject matter of claim 7 together with a separate amplifier connected to each connecting means for amplifying the detection signals; and circuit means connected to the amplifier for gating the detection signal to an output of the circuit means only when the detection signal exceeds a preselected threshold level, indicating a respective detected fault exceeds an acceptable limit.
Claim 12
Dependent Claim
60 words
The subject matter set forth in claim 8 wherein a plurality of circuit means are provided for respective detection signals, and further wherein the outputs of the circuit means are cumulatively combined by utilization means for producing a signal indicative of the overall color-tactile impact of a fault or faults appearing in the area at a given instant of time.
Claim 13
Dependent Claim
100 words
The subject matter set forth in claim 8 together with: means connected to the circuit means for integrating the output of each circuit means; means connected to the integrating means for multiplying the output from each integrating means by Separate weight factors thus ascribing relative importance between the individual detection signals; means connected to the outputs of the multiplying means for summing the multiplied outputs and providing a summation signal therefrom; and means for comparing the summation output with a reference corresponding to an acceptable color-tactile defect level and generating an output therefrom, when the summation output exceeds the reference.
References Cited (Backward Citations)
US3388261A
Cited
US3474254A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |