US4878114A
Expired / Lapsed
US
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Method and apparatus for assessing surface roughness
Assignee: WINDSOR 360 SUNSET AVENUE WINDSOR ONTARIO CANADA N9B 3P4, University of
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Filing: 1988-05-10
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Granted: 1989-10-31
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Expires: 2008-05-10
Abstract
Abstract A relatively low cost processor based optical system is used to carry out the method. An area of the surface whose roughness is to be assessed is illuminated by a light source, and a reflected light is directed to the lens of the video camera. The analog output of the video camera is digitized, and the digital signal is provided to a processor which performs an analysis to provide a parameter indicative of the roughness of the surface.
Inventors
- 👤 Van-Minh Huynh
- 👤 Francis M. Luk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:38
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/30; G01B11/303; G06; G06T; G06T7/00; G06T7/40; G06T7/41; G06T2207/00; G06T2207/30; G06T2207/30108
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
171 words
A processor based optical system for assessing the roughness of a planar surface of a manufactured product; said system comprising: a source of illumination adjustable to illuminate an area of said planar surface; a video camera, having an input lens and an output means, said camera being mountable above said area such that said input lens is trained on said area to provide an analog output representative of surface characteristics of said area; frame grabber means, having an input means connected to said output means of said video camera, said frame grabber means digitizing said analog output to provide digital signals corresponding to said analog output; processor means for performing an analysis of said digital signals and providing a parameter indicative of said roughness; and further including a video monitor having a first input terminal and a second input terminal; said first input terminal of said video monitor being connected to an output of said frame grabber means; said second input terminal being connected to an output of said processor means.
Claim 2
Dependent Claim
171 words
A processor based optical system for assessing the roughness of a planar surface of a manufactured product; said system comprising: a source of illumination adjustable to illuminate an area of said planar surface; a video camera, having an input lens and an output means, said camera being mountable above said area such that said input lens is trained on said area to provide an analog output representative of surface characteristics of said area; frame grabber means, having an input means connected to said output means of said video camera, said frame grabber means digitizing said analog output to provide digital signals corresponding to said analog output; processor means for performing an analysis of said digital signals and providing a parameter indicative of said roughness; and further including a video monitor having a first input terminal and a second input terminal; said first input terminal of said video monitor being connected to an output of said frame grabber means; said second input terminal being connected to an output of said processor means.
Claim 3
Dependent Claim
18 words
A system as defined in claim 1 and including microscope optics between said area and said input lens.
Claim 4
Dependent Claim
18 words
A system as defined in claim 1 wherein said processor comprises a personal computer microprocessor having a monitor.
Claim 5
Dependent Claim
28 words
A system as defined in claim 1 and further including a printer and a plotter, said printer and said plotter being connected to an output of said processor.
Claim 6
Dependent Claim
34 words
A system as defined in claim 1 wherein said frame grabber comprises a digitizer and a frame buffer; an output of said digitizer being connected to said first input terminal of said video monitor.
Claim 7
Dependent Claim
19 words
A system as defined in claim 1 wherein said video camera comprises a CCD (charge coupled device) television camera.
Claim 8
Independent Claim
180 words
A method for assessing the roughness of a planar surface of a manufactured product using a processor based optical system; said system comprising: a source of illumination; a video camera having an input lens; frame grabber means; and processor means; said method comprising: adjusting said source of illumination to illuminate an area of said surface; training said input lens of said video camera on said area whereby to receive reflected light from said area at said camera lens; said camera thereby providing an analog output representative of said area; providing said analog output to said frame grabber means; said frame grabber means digitizing said analog output to provide digital signals corresponding to said analog output; providing said digital signals to said processor; said processor performing an analysis of said digital signals to provide a parameter indicative of said roughness; wherein said system includes a video monitor having a first input thereof connected to said frame grabber means and a second input thereof connected to said processor means; whereby, a magnified image of said area is presented on said video monitor.
Claim 9
Independent Claim
180 words
A method for assessing the roughness of a planar surface of a manufactured product using a processor based optical system; said system comprising: a source of illumination; a video camera having an input lens; frame grabber means; and processor means; said method comprising: adjusting said source of illumination to illuminate an area of said surface; training said input lens of said video camera on said area whereby to receive reflected light from said area at said camera lens; said camera thereby providing an analog output representative of said area; providing said analog output to said frame grabber means; said frame grabber means digitizing said analog output to provide digital signals corresponding to said analog output; providing said digital signals to said processor; said processor performing an analysis of said digital signals to provide a parameter indicative of said roughness; wherein said system includes a video monitor having a first input thereof connected to said frame grabber means and a second input thereof connected to said processor means; whereby, a magnified image of said area is presented on said video monitor.
Claim 10
Dependent Claim
33 words
A method as defined in claim 7 wherein said system includes microscope optics between said area and said lens whereby said reflected light is provided to said camera lens through said microscope optics.
Claim 11
Dependent Claim
38 words
A method as defined in claim 8 wherein said frame grabber comprises a digitizer and a frame buffer; the output of said digitizer being connected to the first input terminal of said video monitor and said frame buffer.
Claim 12
Dependent Claim
66 words
A method as defined in claim 8 wherein said parameter comprises a roughness parameter R which is defined by: R=SD/RMS where: SD=standard deviation of the distribution RMS=root mean square height of the distribution The numerical calculations for these parameters were performed as follows: ##EQU3## F i =number of pixels at grey level X i as determined from the histogram, and n=255 for the Matrox PIP-1024 board.
Claim 13
Dependent Claim
28 words
A method as defined in claim 10 and including the step of determining the skewness of the distribution, said skewness of the distribution being defined as follows: ##EQU4##
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |