Optical angular position detection apparatus and method
US8711345B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 17, 2012 |
| Grant date | Apr 29, 2014 |
| Priority date | — |
| Expiry date | May 17, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/3473
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An annular position detection method provides a plurality of light emitters on a first imaginary circle centered on an axis, the emitters directing individual, well-defined, overlapping light beams to a pair of light detectors positioned on a second imaginary circle centered on that axis. The detectors include pairs of diametrically opposite photosensors producing outputs depending upon the areas thereof exposed to light from the emitters. A light blocker is rotatably mounted on the axis so that the blocker blocks light to different extents of the photosensors depending upon its orientation about the axis. The outputs from all of the photosensors are processed to produce a position signal that varies with the angular position of the blocker and the relative intensities of the emitters are adjusted so that the position signal is substantially linear at all operative angles of the blocker. Apparatus for practicing the method is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.