The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 26, 2014
Filed:
Jul. 08, 2009
Michael Hermann, Tacherting, DE;
Michael Hermann, Tacherting, DE;
Dr. Johnannes Heidenhein GmbH, Traunreut, DE;
Abstract
An optical position-measuring device for detecting the position of two objects movable relative to each other in at least one measuring direction includes a measuring standard which is joined to one of the two objects and possesses an incremental graduation extending in the measuring direction, as well as at least one reference marking at a reference position. The reference marking includes two reference-marking subfields disposed in mirror symmetry with respect to a reference-marking axis of symmetry, each of the subfields being made up of a structure extending in the measuring direction and having a locally changeable graduation period. In addition, the position-measuring device has a scanning unit which is joined to the other of the two objects and to which a scanning device is assigned that is used to generate at least one reference signal at the reference position. The scanning device includes at least one light source emitting divergently in the direction of the measuring standard, as well as a detector system having elements which are disposed along the measuring direction such that, starting from a central detector-system axis of symmetry in the measuring direction, the center-to-center distances between adjacent elements in the same direction change like the graduation periods of the structures in the reference-marking subfields starting from the reference-marking axis of symmetry.