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US4853777A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for evaluating smooth surfaces

Assignee: Ashland LLC
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Filing: 1988-01-29
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Granted: 1989-08-01
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Expires: 2008-01-29
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Abstract

Abstract The short-term and long-term waviness of a smooth surface is determined quantitatively by a method which impinges light radiation onto the surface, detects the resultant light image, and mathematically processes that image. The method permits a fast, non-contact evaluation of a smooth surface with good correlation between the calculated values and the visual observation.

Inventors

  • 👤 Stephen S. Hupp

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 11:57
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/30; G01B11/303

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 151 words
A method for determining the short term waviness and long term waviness of a reflective surface comprising: impinging light radiation onto a portion of the surface at an angle relative to the plane of said surface; detecting discrete images created by the reflected light radiation; digitizing said images to create data points; storing said data points; calculating said short term waviness by mathematically processing said data points from each said discrete image to determine the average height of each said discrete image and then calculating the overall average based on a plurality of said average heights; and determining said long term waviness by first generating a reduced line for each said reflected image, fitting each said reduced line mathematically to produce an idealized fitted line, calculating the standard deviation of each said reduced line from said corresponding idealized line, and calculating an average standard deviation based on each said standard deviation.
Claim 2
Independent Claim 151 words
A method for determining the short term waviness and long term waviness of a reflective surface comprising: impinging light radiation onto a portion of the surface at an angle relative to the plane of said surface; detecting discrete images created by the reflected light radiation; digitizing said images to create data points; storing said data points; calculating said short term waviness by mathematically processing said data points from each said discrete image to determine the average height of each said discrete image and then calculating the overall average based on a plurality of said average heights; and determining said long term waviness by first generating a reduced line for each said reflected image, fitting each said reduced line mathematically to produce an idealized fitted line, calculating the standard deviation of each said reduced line from said corresponding idealized line, and calculating an average standard deviation based on each said standard deviation.
Claim 3
Dependent Claim 14 words
The method of claim 1 wherein said light radiation is produced by a laser.
Claim 4
Dependent Claim 36 words
The method of claim 2 wherein said light radiation is in the shape of straight line, said line transverse to the direction of propagation of said light radiation at the point of striking said reflective surface.
Claim 5
Dependent Claim 24 words
The method of claim 3 wherein said light radiation strikes said surface at an angle in the range of about 30° to about 35°.
Claim 6
Independent Claim 109 words
A method for quantitatively determining the long-term waviness of a reflective smooth surface comprising: impinging lines of laser radiation onto the surface to create discrete images which reflect from said surface; detecting said reflected images by a video camera; digitizing said detected reflected images to create data points; storing said data points; and determining said long-term waviness by first generating a reduced line for each said reflected image, fitting each said reduced line mathematically to a polynomial which determines an idealized line fit, calculating the standard deviation of each said reduced line from said corresponding idealized line, and calculating an average standard deviation based on each said standard deviation.
Claim 7
Independent Claim 109 words
A method for quantitatively determining the long-term waviness of a reflective smooth surface comprising: impinging lines of laser radiation onto the surface to create discrete images which reflect from said surface; detecting said reflected images by a video camera; digitizing said detected reflected images to create data points; storing said data points; and determining said long-term waviness by first generating a reduced line for each said reflected image, fitting each said reduced line mathematically to a polynomial which determines an idealized line fit, calculating the standard deviation of each said reduced line from said corresponding idealized line, and calculating an average standard deviation based on each said standard deviation.
Claim 8
Independent Claim 149 words
A method for quantitatively determining the short-term waviness and long-term waviness of a reflective smooth surface comprising: impinging lines of laser radiation onto the surface at an angle relative to the plane of said surface to create discrete images which reflect from said surface; detecting said reflected images by a video camera; digitizing said detected reflected images to create data points; storing said data points determining said short-term waviness by first calculating the average height of each said reflected image and then calculating the overall average based on each said average height; and determining said long-term waviness by first generating a reduced line for each said reflected image, fitting each said reduced line mathematically to a polynomial which determines an idealized line fit, calculating the standard deviation of each said reduced line from said corresponding idealized line, and calculating an average standard deviation based on each said standard deviation.
Claim 9
Independent Claim 149 words
A method for quantitatively determining the short-term waviness and long-term waviness of a reflective smooth surface comprising: impinging lines of laser radiation onto the surface at an angle relative to the plane of said surface to create discrete images which reflect from said surface; detecting said reflected images by a video camera; digitizing said detected reflected images to create data points; storing said data points determining said short-term waviness by first calculating the average height of each said reflected image and then calculating the overall average based on each said average height; and determining said long-term waviness by first generating a reduced line for each said reflected image, fitting each said reduced line mathematically to a polynomial which determines an idealized line fit, calculating the standard deviation of each said reduced line from said corresponding idealized line, and calculating an average standard deviation based on each said standard deviation.
Claim 10
Dependent Claim 26 words
The method of claim 6 wherein said lines of laser radiation impinge said surface at an angle in the range of about 60° to about 5°.
Claim 11
Dependent Claim 26 words
The method of claim 6 wherein said lines of laser radiation impinge said surface at an angle in the range of about 35° to about 30°.
Claim 12
Dependent Claim 21 words
The method of claim 6 wherein said lines of laser radiation are impinged onto said surface in parallel, equally spaced intervals.
Claim 13
Independent Claim 196 words
A method for quantitatively determining the short term waviness and long term waviness of a reflective smooth surface wherein said short term waviness and said long term waviness are intercomparable with the short term waviness and long term waviness of at least one other reflective smooth surface, comprising: impinging lines of laser radiation onto said reflective smooth surface at an angle relative to the plane of said reflective smooth surface to create discrete images which reflect therefrom; determining a calibration value relatable to the size of at least one of said reflected images; digitizing said detected reflected images to create data points; storing said data points on computer storage means; determining said short term waviness by first calculating the average height of each said reflected image and then calculating the overall average based on each said average height; and determining said long term waviness by first generating a reduced line for each said reflected image, ffitting each said reduced line mathematically to a polynomial which determines an idealized line fit, calculating the standard deviation of each said reduced line from said corresponding idealized line, and calculating an average standard deviation based on each said standard deviation.
Claim 14
Independent Claim 196 words
A method for quantitatively determining the short term waviness and long term waviness of a reflective smooth surface wherein said short term waviness and said long term waviness are intercomparable with the short term waviness and long term waviness of at least one other reflective smooth surface, comprising: impinging lines of laser radiation onto said reflective smooth surface at an angle relative to the plane of said reflective smooth surface to create discrete images which reflect therefrom; determining a calibration value relatable to the size of at least one of said reflected images; digitizing said detected reflected images to create data points; storing said data points on computer storage means; determining said short term waviness by first calculating the average height of each said reflected image and then calculating the overall average based on each said average height; and determining said long term waviness by first generating a reduced line for each said reflected image, ffitting each said reduced line mathematically to a polynomial which determines an idealized line fit, calculating the standard deviation of each said reduced line from said corresponding idealized line, and calculating an average standard deviation based on each said standard deviation.

References Cited (Backward Citations)

US4249823A Cited
US4476489A Cited
US4468426A Cited
US4647197A Cited
US4634281A Cited
US4629319A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-07-31 1993-01-30 1993-08-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-07-31 1997-01-30 1997-08-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-07-31 2001-01-30 2001-08-01 $7700.00 Window Closed / Lapsed

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