Film stress measurement system having first and second stage means
US5118955A · kind A · utility
14Cited by
6References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 26, 1989 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | May 26, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/306
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for measuring the curvature of a surface includes a laser for emitting a beam of light to be incident upon the surface; a photodetector for detecting light reflected by the surface; a first stage for selectively moving the surface in a direction normal to the direction of the incident beam; a second stage for selectively moving the photodetector in a direction normal to the reflected beam; a sensor connected to the photodetector for detecting the displacement of the reflected beam relative to the photodetector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.