Fringe pattern discriminator for interferometer using diffraction gratings
US5724137A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1996 |
| Grant date | Mar 3, 1998 |
| Priority date | — |
| Expiry date | Jun 27, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An object fringe pattern is distinguished from other fringe patterns in an interferogram produced by an interferometer using a pair of diffraction gratings for separating and recombining test and reference beams. The object on which a test beam is grazingly incident is moved in X and Y directions in a plane perpendicular to an optical axis of the interferometer to change the brightness regions of the object fringe pattern. A computer identifies pixels whose irradiance changes in response to object movement, and then only irradiance data from the identified pixels is used in analyzing the interferogram to produce a measurement of a surface of the object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.