US4952062A — Method and apparatus for detecting flaws in fabric

Claim 1

Independent Claim 97 words

In the method of examining a web of fibrous material for the presence of flaws wherein measurements indicative of the intensity of light transmitted through the web are compared with a range of measurement values indicative of the intensity of light transmitted by a web of acceptable quality, THE IMPROVEMENT COMPRISING the steps of determining the difference between each measurement and a preselected value within the range, adding each determined difference to a running total of such differences and producing a signal when the running total exceeds a preselected limit indicative of the presence of a flaw.

Claim 2

Dependent Claim 97 words

In the method of examining a web of fibrous material for the presence of flaws wherein measurements indicative of the intensity of light transmitted through the web are compared with a range of measurement values indicative of the intensity of light transmitted by a web of acceptable quality, THE IMPROVEMENT COMPRISING the steps of determining the difference between each measurement and a preselected value within the range, adding each determined difference to a running total of such differences and producing a signal when the running total exceeds a preselected limit indicative of the presence of a flaw.

Claim 3

Dependent Claim 31 words

The improvement of claim 1 further comprising the step of subtracting a determined difference from the running total when a preselected number of subsequent differences have been added to the total.

Claim 4

Independent Claim 99 words

A method of detecting flaws in fabric comprising the steps of: establishing a standard indicative of the intensity of light transmitted by fabric of acceptable quality; illuminating the fabric; making a plurality of successive measurements of the intensity of light transmitted by the fabric; comparing each successive measurement with the standard and establishing a factor characteristic of the difference between the measurement and the standard; adding each factor to a running total of such factors; comparing the running total with a preselected limit indicative of a flaw; and producing a signal when the running total exceeds the preselected limit.

Claim 5

Independent Claim 99 words

A method of detecting flaws in fabric comprising the steps of: establishing a standard indicative of the intensity of light transmitted by fabric of acceptable quality; illuminating the fabric; making a plurality of successive measurements of the intensity of light transmitted by the fabric; comparing each successive measurement with the standard and establishing a factor characteristic of the difference between the measurement and the standard; adding each factor to a running total of such factors; comparing the running total with a preselected limit indicative of a flaw; and producing a signal when the running total exceeds the preselected limit.

Claim 6

Dependent Claim 28 words

The method of claim 3 wherein the step of comparing the running total with a preselected limit is performed as each factor is added to the running total.

Claim 7

Dependent Claim 39 words

The method of claim 3 further including the step of subtracting the factor characteristic of a difference from the running total when a preselected number of subsequent factors characteristic of subsequent differences have been added to the running total.

Claim 8

Dependent Claim 61 words

The method of claim 3 wherein the step of establishing a standard comprises the steps of: illuminating a sample of the fabric known to be of acceptable quality; making a plurality of measurements of the intensity of light transmitted by the sample; calculating the average value of the plurality of measurements; and calculating the standard deviation of the plurality of measurements.

Claim 9

Dependent Claim 41 words

The method of claim 6 wherein the step of comparing each successive measurement with the standard comprises the step of determining the difference between the measurement and the average value, and expressing the difference in units of the calculated standard deviation.

Claim 10

Dependent Claim 67 words

The method of claim 3 further including the step of moving the fabric along a path and wherein the plurality of successive measurements of the intensity of light transmitted by the fabric are made along at least one line substantially parallel to the direction of movement of the fabric and wherein the distance between each successive measurement substantially corresponds to the mesh size of the woven fabric.

Claim 11

Independent Claim 131 words

A method of detecting flaws in fabric, said comprising the steps of: establishing a standard indicative of an optical property of fabric of acceptable quality; moving fabric to be examined past an optical sensor adapted to make a plurality of measurements of the same optical property of the woven fabric with successive measurements falling along at least one line oriented substantially parallel to the direction of movement of the fabric; determining the difference between each of the measurements and the standard and establishing a factor corresponding to the difference; adding each established factor to a running total of such factors; comparing the running total to a preselected threshold value as each factor is added to the running total; and producing a signal if the running total exceeds the preselected threshold value.

Claim 12

Independent Claim 131 words

A method of detecting flaws in fabric, said comprising the steps of: establishing a standard indicative of an optical property of fabric of acceptable quality; moving fabric to be examined past an optical sensor adapted to make a plurality of measurements of the same optical property of the woven fabric with successive measurements falling along at least one line oriented substantially parallel to the direction of movement of the fabric; determining the difference between each of the measurements and the standard and establishing a factor corresponding to the difference; adding each established factor to a running total of such factors; comparing the running total to a preselected threshold value as each factor is added to the running total; and producing a signal if the running total exceeds the preselected threshold value.

Claim 13

Dependent Claim 35 words

The method of claim 9 further comprising the step of subtracting the factor corresponding to a measurement from the running total when a preselected number of subsequent factors have been added to the running total.

Claim 14

Dependent Claim 85 words

The method of claim 9 wherein the step of establishing a standard comprises the steps of: moving the fabric of acceptable quality past the optical sensor; making a plurality of measurements of the optical property of the sample with successive measurements falling along at least one line oriented substantially parallel to the direction of movement of the sample; calculating the average value of the plurality of measurements; calculating the standard deviation of the plurality of measurements; and wherein the calculated average value represents the standard.

Claim 15

Dependent Claim 30 words

The method of claim 11 wherein each of the differences is expressed in units of the calculated standard deviation and wherein the factors are proportional to the difference so expressed.

Claim 16

Dependent Claim 18 words

The method of claim 9 wherein the optical property is the intensity of light transmitted by the fabric.

Claim 17

Dependent Claim 18 words

The method of claim 9 wherein the optical property is the intensity of light reflected by the fabric.

Claim 18

Independent Claim 165 words

An apparatus for detecting flaws in a sheet of web material, said apparatus comprising: means for establishing a standard indicative of the intensity of light transmitted by a sample of the web having acceptable quality; means for advancing the sheet of web material along a path; means for making a plurality of measurements of the intensity of light transmitted by the web material as the material moves along said path, said plurality of measurements falling along at least one line oriented substantially parallel to the direction of advancement of the sheet; means for comparing each of said measurements to said standard and establishing a factor characteristic of the deviation of the measurement from the standard; means for adding each of said factors to a running total of such factors; means for comparing the running total to a preselected threshold value as each of said factors is added to the total; and means for producing a signal when the running total exceeds the preselected threshold value.

Claim 19

Independent Claim 165 words

An apparatus for detecting flaws in a sheet of web material, said apparatus comprising: means for establishing a standard indicative of the intensity of light transmitted by a sample of the web having acceptable quality; means for advancing the sheet of web material along a path; means for making a plurality of measurements of the intensity of light transmitted by the web material as the material moves along said path, said plurality of measurements falling along at least one line oriented substantially parallel to the direction of advancement of the sheet; means for comparing each of said measurements to said standard and establishing a factor characteristic of the deviation of the measurement from the standard; means for adding each of said factors to a running total of such factors; means for comparing the running total to a preselected threshold value as each of said factors is added to the total; and means for producing a signal when the running total exceeds the preselected threshold value.

Claim 20

Dependent Claim 34 words

The apparatus of claim 15 further comprising means for subtracting the factor characteristic of a deviation from the running total when a preselected number of subsequent factors have been added to the running total.

Claim 21

Dependent Claim 88 words

The apparatus of claim 16 wherein said means for making a plurality of measurements comprises an array of optical sensors arranged in closely spaced relationship into two rows with said rows being oriented substantially transversely relative to the direction of advancement of said sheet and with each sensor being closely adjacent the surface of said sheet, each of said sensors in said second row being offset relative to adjacent sensors in said first row, and means for illuminating the opposite surface of said sheet adjacent said sensor array.

Claim 22

Dependent Claim 49 words

The apparatus of claim 17 wherein each of said sensors is a photoresistor producing a voltage signal proportional to the intensity of light impinging thereon and wherein said means for illuminating said material is an elongated fluorescent bulb arranged in substantially spaced parallel relationship relative to said sensor array.

Claim 23

Dependent Claim 44 words

The apparatus of claim 18 wherein said means for establishing, comparing, adding and subtracting comprises a microprocessor electrically connected to said sensor array and adapted to measure the voltage signal produced by each sensor in said array as said sheet advances past said array.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-08-27	1994-02-26	1994-08-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-08-27	1998-02-26	1998-08-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-08-27	2002-02-26	2002-08-28	$7700.00	Window Closed / Lapsed

Method and apparatus for detecting flaws in fabric

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