Position measuring device

US11073410B2 · kind B2 · utility

Assignee

• DR. JOHANNES HEIDENHAIN GMBH · DE

Inventors

• Stefan Weis · Rötteln, DE
• Daniel Frese · Traunstein, DE
• Wolfgang Holzapfel · Obing, DE

Key dates

• Filing date: Jan 7, 2019
• Grant date: Jul 27, 2021
• Expiry date: Oct 11, 2039

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D2205/90
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A position-measuring device for determining an absolute position includes a measuring scale and a scanning unit that is movable relative to the measuring scale along at least one measuring direction. To generate a scannable signal pattern, the measuring scale has a measuring graduation which includes a raster of stripe elements arranged along the measuring direction at a measuring-scale longitudinal period. For the encoding of an absolute position, the stripe elements have a periodic structure having a measuring-scale transverse period along a transverse direction that is oriented perpendicular to the measuring direction. For scanning the signal pattern, the scanning unit has a two-dimensional detector system having a plurality of detector elements, which includes multiple detector columns having a plurality of detector elements in each case. The detector columns are periodically arranged along the measuring direction and the detector elements are periodically arranged along the transverse direction, so that by scanning the signal pattern, at least three periodic partial incremental signals are able to be generated with regard to relative movements along the measuring direction, as…