Optical position encoder having alignment indicators providing quantitative alignment indications
US7067797B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 2004 |
| Grant date | Jun 27, 2006 |
| Priority date | — |
| Expiry date | Oct 20, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/34707
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical encoder includes an optical source, a scale, an optical detector and signal processing circuitry. The scale is operative with a light beam from the source to generate an optical pattern such as a line pattern extending in an X direction of relative movement between the scale and the source. The detector generates analog detector output signals indicative of the location of the optical pattern on the detector in an alignment direction orthogonal to the X direction. The detector may include two bi-cell elements spaced apart in the X direction, each element including two cells of complementary shape, such as a sharks-tooth. The signal processing circuitry operates in response to the detector output signals to generate an alignment value indicating a polarity and a magnitude of misalignment between the detector and the scale in the alignment direction. A method of providing information to a user regarding alignment of a detector and an encoder scale employs a graphical alignment indicator displayed on a computer display. The graphical alignment indicator has a bipolar indicator scale and a marker whose location on the scale is based on the alignment values such that the magn…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.