Optical position measuring system
US7112782B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 13, 2004 |
| Grant date | Sep 26, 2006 |
| Priority date | — |
| Expiry date | Mar 17, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical position measuring system including a scale and a scanning unit. The scanning unit includes a light source that emits light beams and a periodic scanning graduation having scanning graduation marks arranged periodically at a scanning graduation period along a measuring direction. The scanning unit further including a detector arrangement. The scanning graduation or the scale graduation includes at least three partial tracks, which adjoin perpendicularly with respect to the measuring direction, and graduation marks associated with each of the at least three partial tracks have a defined and constant offset spacing from their nominal positions, wherein the offset spacings associated with adjoining ones of the at least three partial tracks differ, so that filtering of undesired harmonic waves out of the at least one periodic scanning signal results from said offset spacings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.