Apparatus and method for shape measurement using interferometer
US6552807B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 2000 |
| Grant date | Apr 22, 2003 |
| Priority date | — |
| Expiry date | Jun 28, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/303
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A phase shift interferometer (4) images a plurality of interference fringe images each generated from interference between a test light reflected at a test surface (3a) and a reference light reflected at an reference surface (5) by emitting a coherent light to both surfaces while varying a phase difference between the test light and the reference light from image to image. A surface shape analyzer (12) analyzes the plurality of interference fringe images taken by the phase shift interferometer (4) to obtain surface shape information of the test surface (3a). A typical plane computer (13) computes a typical plane of the test surface (3a) on the basis of the surface shape information obtained from the surface shape analyzer (12). An oblique angle computer (14) computes an oblique angle of the typical plane computed by the typical plane computer (13) to the reference surface (5). An attitude adjusting mechanism (2) automatically adjusts the attitude of the test surface (3a) relative to the reference surface (5) on the basis of information of the oblique angle computed by the oblique angle computer (14).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.