Patent · US Active

Reference mark detector arrangement

US10281301B2 · kind B2 · utility

0Cited by
13References
18Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 26, 2014
Grant dateMay 7, 2019
Priority date—
Expiry dateSep 28, 2035

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01D5/366
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An encoder apparatus comprising a scale comprising scale features in at least one track which define a series of incremental scale marks and at least one reference mark and a readhead comprising a light source, a diffraction grating, an incremental photodetector and a reference photodetector comprising at least two detector channels. The features defining the at least one reference mark are configured such that the at least one reference mark as resolvable by each of the at least two detector channels comprises a single feature. The optical arrangement of the encoder is such that a non-imaged representation of at least the track in which the at least one reference mark is contained falls onto the detector.

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