Patent · US Expired

Multi-track absolute encoder

US6366047B1 · kind B1 · utility

9Cited by
4References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 13, 2000
Grant dateApr 2, 2002
Priority date—
Expiry dateJul 13, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01D5/2497
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A position encoder and a method for estimating absolute position using two or more diffractive grating tracks of differing periods to generate interference fringe patterns on a multi-track sensor. Detectors, corresponding to the diffractive grating tracks, detect the interference fringes. A first processing circuitry coupled to the detectors extract phase signals from the signals from the detectors. A second processing circuitry then estimates the cycle counts of the track signals based on the phase signals from the first processing circuitry. The absolute position is estimated by combining the cycle count, the fractional fringe value, and the grating period.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.