Optical position measuring device

US9733068B2 · kind B2 · utility

Assignee

• DR. JOHANNES HEIDENHAIN GMBH · DE

Inventors

• Jörg Drescher · Samerberg, DE
• Wolfgang Holzapfel · Obing, DE
• Ralph Joerger · Traunstein, DE
• Thomas Kälberer · Weil der Stadt, DE
• Markus Meissner · Teupitz, DE
• Bernhard Musch · Otterfing, DE
• Erwin Spanner · Traunstein, DE

Key dates

• Filing date: Jun 8, 2015
• Grant date: Aug 15, 2017
• Expiry date: Jun 8, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/34707
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In an optical position measuring device for detecting the relative position of a first measuring standard and a second measuring standard, movable relative to each other along at least one measuring direction, at a splitting grating, a beam bundle emitted by a light source is split up into at least two partial beam bundles. When passing through scanning beam paths, the partial beam bundles undergo different polarization-optical effects. After the differently polarized partial beam bundles are recombined at a combination grating, a plurality of phase-displaced, displacement-dependent scanning signals is able to be generated from the resulting beam bundle. No polarization-optical components are arranged in the scanning beam paths of the partial beam bundles between the splitting and recombination. To generate the different polarization-optical effects on the partial beam bundles, a conically incident illumination beam bundle impinges upon the splitting grating, the incident illumination beam bundle extending in a plane perpendicular to the measuring direction at an angle other than 0°, the plane of incidence being defined by the grating normal to the splitting grating and the directi…