Absolute position measurement apparatus and method
US9043182B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 2008 |
| Grant date | May 26, 2015 |
| Priority date | — |
| Expiry date | Dec 9, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An absolute position measurement apparatus measures an absolute position of an object to be measured using a first light source and a second light source which has coherency lower than that of the first light source. The absolute position measurement apparatus includes a measurement part which measures a point where phases of interference signals from the first and the second light sources coincide with each other or a point where an intensity of the interference signal from the second light source is maximized, an origin defining part which defines the point measured by the measurement part as an origin position, a phase storing part which stores the phase of the interference signal from the first light source at the origin position, an origin redefining part which redefines the origin position, and a position calculating part which calculates the absolute position of the object to be measured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.