Indexed optical encoder, method for indexing an optical encoder, and method for dynamically adjusting gain and offset in an optical encoder
US8476579B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 19, 2012 |
| Grant date | Jul 2, 2013 |
| Priority date | — |
| Expiry date | Oct 19, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F17/18
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical encoder may include an encoder disk, an illumination system, and a detector to detect light diffracted from the encoder disk. The encoder disk may include a signal track comprising a diffraction grating, and an index track comprising a reflective index mark, wherein a width of the index mark is larger than a pitch of the diffraction grating. An indexing method may include providing an encoder disk, providing an illumination system to direct light to the encoder disk, providing a detector structured to detect light diffracted from the encoder disk, calculating an estimated count of quadrature states from a rising edge of an index pulse to a middle of the index interval, and calculating the quadrature state at an approximate center of the index pulse. A dynamic parameter correction method may include calculating a target gain and offset and correcting values based on the target gain and offset.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.