Optical wave interference measuring apparatus
US7982882B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 2009 |
| Grant date | Jul 19, 2011 |
| Priority date | — |
| Expiry date | Oct 1, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/0271
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The relative position of a test surface is sequentially changed from a reference position where a surface central axis is aligned with a measurement optical axis such that the measurement optical axis is sequentially moved to a plurality of annular regions obtained by dividing the test surface in a diametric direction. The test surface is rotated on a rotation axis whenever the relative position is changed. Measurement light that travels while being converged by a Mirau objective interference optical system is radiated to the rotating test surface, and a one-dimensional image sensor captures interference fringes at each of a plurality of rotational positions. The shape information of each annular region is calculated on the basis of the captured interference fringes at each rotational position, and the shape information is connected to calculate the shape information of the entire measurement region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.