Illumination portion for an adaptable resolution optical encoder
US8941052B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 2012 |
| Grant date | Jan 27, 2015 |
| Priority date | — |
| Expiry date | Sep 17, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/34792
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An illumination portion is used in an optical encoder which comprises a scale grating, an imaging portion, and a detector portion. A light source outputs light having a wavelength λ. A structured illumination generating portion inputs the light and outputs structured illumination. The structured illumination comprises an illumination fringe pattern oriented transversely to the measuring axis direction. A first filtering lens focuses the structured illumination proximate to a plane of the spatial filter aperture configuration. A spatial filtering aperture configuration includes a central portion that blocks zero-order portions of the structured illumination and an open aperture portion that outputs +1 order and −1 order portions of the structured illumination to a second filtering lens. The second filtering lens outputs the structured illumination to a plane of the scale grating with an illumination fringe pitch PMI along the measuring axis direction at a plane coinciding with the scale grating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.