Optical position measuring device with a beam splitter

US6535290B1 · kind B1 · utility

Assignee

• JOHANNES HEIDENHAIN GmbH · DE

Inventors

• Erwin Spanner · Traunstein, DE
• Jurgen Thiel · Surberg, DE

Key dates

• Filing date: Apr 1, 1999
• Grant date: Mar 18, 2003
• Expiry date: Apr 1, 2019

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B2290/30
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A position measuring device for determining the position of two parts that are movable relatively to one another in the measuring direction, which, in addition, includes the feature of enabling an absolute reference to be established during the measurement. To this end, the position measuring device includes a light source, as well as a beam-splitter element, which splits the beam of rays emitted by the light source into at least one first and one second beam component, which are preferably oriented parallel to one another after leaving the beam-splitter element. Provision is also made for a reference reflector, as well as a measuring reflector, upon which the two beam components strike. A reference marking, as well as a scanning unit are arranged at the measuring reflector and at the reference reflector to produce a reference pulse signal at the position of the stationary reference reflector.