Patent US3127992A successfully refreshed from Google Patents.
US3904293A
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Optical method for surface texture measurement
Assignee: Individual
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Filing: 1973-12-06
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Granted: 1975-09-09
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Expires: 1993-12-06
Abstract
Abstract A non-contact method for measuring fine and coarse textural characteristics of material surfaces by detecting the light reflected from the surface and analyzing the degree of depolarization of the polarized incident light. The surface may be either stationary or moving with respect to the measuring system.
Inventors
- 👤 Sherman Gee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:32
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/21
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
157 words
A method for instantaneously measuring road pavement surface textural characteristics from a moving vehicle comprising the steps of: directing a beam of polarized light from said moving vehicle at an angle of incidence theta with respect to the surface normal; collecting the light reflected from said surface at an angle of reflection theta with respect to the surface normal; separating the collected light by means of a device for splitting the light into a first principal polarized wave component and second orthogonal polarized wave component of polarized light; directing said first principal polarized wave component into a first photodetector and said second orthogonal polarized wave component into a second photodetector; and comparing the outputs of said first and second photodetectors by measuring the ratio of the amplitudes of said first and second components of light to indicate the change in polarization of said light source, said polarization change providing the textural characteristics of said road pavement surface.
Claim 2
Independent Claim
157 words
A method for instantaneously measuring road pavement surface textural characteristics from a moving vehicle comprising the steps of: directing a beam of polarized light from said moving vehicle at an angle of incidence theta with respect to the surface normal; collecting the light reflected from said surface at an angle of reflection theta with respect to the surface normal; separating the collected light by means of a device for splitting the light into a first principal polarized wave component and second orthogonal polarized wave component of polarized light; directing said first principal polarized wave component into a first photodetector and said second orthogonal polarized wave component into a second photodetector; and comparing the outputs of said first and second photodetectors by measuring the ratio of the amplitudes of said first and second components of light to indicate the change in polarization of said light source, said polarization change providing the textural characteristics of said road pavement surface.
Claim 3
Dependent Claim
34 words
A method as recited in claim 1 wherein said polarized light is linearly polarized, said vehicle is moving at normal road speed, said light is a laser, and said separator is a beam splitter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |