Speckle sizing and sensor dimensions in optical positioning device
US7042575B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 2005 |
| Grant date | May 9, 2006 |
| Priority date | — |
| Expiry date | May 13, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/68
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
One embodiment relates to an optical displacement sensor for sensing transverse displacement of a data input device relative to a surface by determining displacement of optical features in a succession of frames. The sensor includes at least a coherent light source, illumination optics to illuminate a portion of the surface, imaging optics, and a first array of photosensitive elements having a periodic distance. The illuminator and the detector are configured to produce on the first array of photosensitive elements an intensity pattern of light reflected from the illuminated portion of the surface. The intensity pattern comprises a plurality of speckles having an average speckle diameter which is between one half and two times the periodic distance of the array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.