Apparatus for testing surface roughness
US4290698A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 23, 1979 |
| Grant date | Sep 22, 1981 |
| Priority date | — |
| Expiry date | Aug 23, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/303
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Surface roughness is tested by an optical probing method which involves scanning a beam of light from a laser over a specimen workpiece via a semi-reflecting mirror and a cylindrical lens and detecting the specular component of the light reflected back through the lens and the semi-reflecting mirror to a photomultiplier the output from which is fed to an electronic processor circuit which derive a numerical value representing the mean intensity of the reflected radiation. A workpiece to be tested is then substituted for the specimen workpiece and a new numerical value derived. The two numerical values are compared, as by division or subtraction to obtain an output signal representing the relative surface roughness of the workpiece under test with respect to that of the specimen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.