Foucault method for testing an optical surface
US5155544A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 1990 |
| Grant date | Oct 13, 1992 |
| Priority date | — |
| Expiry date | Jan 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/0257
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The Foucault or knife-edge method may be employed for testing an optical surface defined by an imaging device, for example, a mirror surface, to ascertain its characteristics, for example, whether or not it is a source of optical aberrations. To this end, the traditional Foucault knife-edge method typically employs a knife-edge that comprises a metal razor blade. The present method, in contrast, provides an improved Foucault method, and features a novel optical element suitable for employment in the method. The optical element comprises a transparent substrate, and a coating material that can adhere to at least a portion of the transparent substrate, thereby forming at least one knife-edge pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.