Patent · US Expired

Absolute position detection within 1 revolution using 3-channel incremental encoders with high resolution index track

US5939712A · kind A · utility

9Cited by
2References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 30, 1997
Grant dateAug 17, 1999
Priority date—
Expiry dateMay 30, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01D5/2455
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

The quasi-absolute encoder module determines absolute position within one mechanical rotation. The encoder module includes a three channel position encoder and detection circuitry that includes a read-only memory (ROM). There are three channels: A, B, and I. Channels A and B have four periods and channel B is offset from channel A by 90.degree. in phase. Channel I has a unique sequence. The address generated by sampling this unique sequence corresponds to an address in ROM. The address indicates the position of the rotating shaft on which the codewheel is attached.

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