Method and apparatus for measurement of roughness and hardness of a surface
US5486924A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 22, 1993 |
| Grant date | Jan 23, 1996 |
| Priority date | — |
| Expiry date | Dec 22, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Light is focused on an interface between a transparent probe and a surface to be analyzed. The probe is lowered onto the surface using a computer-controlled actuator. Light reflected from the surface of the probe which is closest to the surface and the surface itself recombines, producing interference effects from the spacing between the probe and the surface over a 2-dimensional area. Since the shape of the probe in known beforehand, the profile of the surface can be readily calculated from the 2-dimensional measurement of the spacing between the probe and the surface. This surface profile indicates the roughness of the surface. The surface hardness and other surface properties can be measured by pressing the probe onto the surface. The contact load between the probe and the surface is detected by a load cell. The force with which the probe is being pressed onto the surface is measured using the load cell. The surface profile can continue to be measured interferometrically while it is being deformed by the probe. The measurement of surface deformation as a function of contact pressure allows the measurement of surface hardness while causing a minimum amount of damage to the surfac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.