Optical encoder applying substantially parallel light beams and three periodic optical elements
US7589314B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 2005 |
| Grant date | Sep 15, 2009 |
| Priority date | — |
| Expiry date | Oct 13, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical encoder for measuring a relative movement of a first scale plate and a second scale plate, comprises: a light source; a first scale plate which converts light from the light source into a cyclic light quantity distribution; a second scale plate which cyclically makes spatial modulation on the light beams from the first scale plate; a third scale plate having slits which allow the light beams from the second scale plate to pass therethrough; and a light-receiving element which receives the light beams from the third scale plate; a lens which converts light from the light source into substantially parallel light beams; and an optic array which converges or diffuses light beams in the direction of periodic change and generates a cyclic light quantity distribution on the first scale plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.