Optical method and system for measuring three-dimensional surface topography of an object having a surface contour
US6268923A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1999 |
| Grant date | Jul 31, 2001 |
| Priority date | — |
| Expiry date | Oct 7, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N13/271
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical method and system for measuring three-dimensional surface topography by providing high resolution contour measurements of an object using interferometric methods. The invention utilizes co-sight detector technology to provide at least three independent images of exactly the same object location, with a known fringe pattern optically introduced to each of the images. Each of the fringe patterns have a known phase difference relative to the phase appearing on each of the other images. Furthermore, the images have the same perspective relative to the object and may be collected simultaneously. This simultaneous collection of multiple phase images allows very high speed 3D data generation. Previous limitations of phase shift technology such as sample motion and vibration can be eliminated. The method may use continuous or strobed illumination. In addition, the system can be built without moving parts of any kind, resulting in a cheaper assembly, with improved repeatability over previous phase shifting techniques.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.