Optical translation measurement
US6246482A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 1999 |
| Grant date | Jun 12, 2001 |
| Priority date | — |
| Expiry date | Mar 8, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/0338
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining the relative motion of a surface with respect to a measurement device comprising: PA1 illuminating the surface with incident illumination such that illumination is reflected from portions of the surface; PA1 placing a partially reflecting object, which is part of the measuring device, adjacent to the surface, wherein part of the incident illumination is reflected or diffracted by the object, as a reference illumination; PA1 coherently detecting the illumination reflected from the surface, utilizing the illumination reflected from or diffracted by the object as a local oscillator, to form a signal; PA1 determining the relative motion of the surface from the signal; PA1 varying the phase of the illumination reflected from or diffracted by the object with respect to that reflected from the surface; and PA1 determining the direction of relative motion parallel to the surface based on a characteristic of the signal caused by said varied relative phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.