Optical position-measuring device

摘要

An optical position-measuring device includes a measuring standard and a scanning unit. The measuring standard includes an incremental graduation and at least one reference marking at a reference position. The reference marking has two reference-marking subfields disposed in mirror symmetry relative to a reference-marking axis of symmetry, each of the subfields including a grating structure having a locally changeable graduation period. The scanning unit includes a divergently emitting light source, one or more gratings, and a reference-signal detector system. The reference-signal detector system has at least four detector arrays formed and positioned such that, from the scanning of the reference marking via the reference-signal detector system, first and second pairs of partial reference signals result, in each case having a signal pattern in phase opposition. The first pair of partial reference signals is offset by an offset amount relative to the second pair of partial reference signals.

主权项

1. An optical position-measuring device for detecting a position of two objects movable relative to each other in at least one measuring direction, comprising:
a measuring standard joined to one of the two objects and including an incremental graduation extending in the measuring direction and at least one reference marking at a reference position, the reference marking including two reference-marking subfields arranged in mirror symmetry relative to a reference-marking axis of symmetry, each reference-marking subfield including a grating structure that extends in the measuring direction and has a locally changeable graduation period; and a scanning unit joined to the other one of the two objects and including a divergently emitting light source, at least one grating, and a reference-signal detector system; wherein the reference-signal detector system includes at least four detector arrays, each detector array including a plurality of detector elements; and wherein the detector arrays are adapted to form, from scanning of the reference marking via the reference-signal detector system, a first pair of partial reference signals and a second pair of partial reference signals, each having a signal pattern in phase opposition, the first pair of partial reference signals offset along the measuring direction by an offset amount relative to the second pair of partial reference signals.