Readhead for an opto-electronic rotary encoder
US5886352A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Jul 1, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A readhead for an opto-electronic encoder includes a light source, an analyser grating and a detector. The light source illuminates a scale of the opto-electronic encoder such that the light passed on by the scale forms a periodic light pattern. The analyser grating interacts with the periodic light pattern to generate a resultant fringe pattern. The resultant fringe pattern is incident upon the detector which generates a plurality of phase shifted cyclically modulating signals upon relative movement of the readhead positioned in registration with the scale. Either the periodic light pattern or the resultant fringe pattern is a linear pattern while a remaining one of the periodic light pattern and the resultant fringe pattern is an angular pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.