Rotary encoder using reflected light
US5036192A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1990 |
| Grant date | Jul 30, 1991 |
| Priority date | — |
| Expiry date | Nov 6, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention discloses a linear/rotary encoder for detecting the state of movement of a grating. The encoder of this invention comprises a system for directing a coherent beam of light onto a predetermined position or positions of a diffraction grating formed on an object to be measured, a converging optical system having a reflection plane at a position on which light is converged, for again making incident on the respective different positions diffracted lights which exit from the position, an interference optical system for forming interference fringes by superposing beam diffracted from the diffraction grating at the predetermined position or positions, and light receiving elements for photoelectrically converting the interference fringes obtained through the interference optical system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.