Non-harmonic cyclic error compensation in interferometric encoder systems
US9146093B2 · kind B2 · utility
1Cited by
32References
32Claims
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Key dates
| Filing date | Nov 8, 2012 |
| Grant date | Sep 29, 2015 |
| Priority date | — |
| Expiry date | Nov 20, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/681
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method includes obtaining, from a detector of an interferometry system, an interference signal based on a combination of a first beam and a reference beam, subsequent to the first beam being diffracted by an encoder scale, obtaining, through an electronic processor, an error compensation signal based on a non-harmonic cyclic error that modifies the interference signal, and outputting information about a change in a position of the encoder scale relative to an optical assembly of the interferometry system based on the interference signal and the error compensation signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.