Optical encoder using off-axis imaging through a lens
US8637805B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2010 |
| Grant date | Jan 28, 2014 |
| Priority date | — |
| Expiry date | Jan 13, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/34
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A miniaturized optical encoder capable of obtaining a sufficient amount of light in the light receiving element is provided. An optical encoder 1 includes a scale 2 having a scale track 2′ and a readhead 3 having a light source 31 that emits light to the scale track 2′, a scale-side lens 32 that transmits the light emitted from the light source 31 to the scale track 2′, and a light receiving element 33 that receives the light reflected by the scale track 2′ through the scale-side lens 32. The light source 31 is arranged between the scale-side lens 32 and the light receiving element 33. An optical axis Lsrc of the light source 31 is matched with an optical axis Ls of the scale-side lens 32 in a reading direction of the scale 2 and is separated from an optical axis Ls of the scale-side lens 32 by a predetermined distance D in a direction perpendicular to the reading direction of the scale 2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.