Patent ID: 8848184
Filing Date: 2014-09-30
Classification: G01D

Abstract:
1. An optical position-measuring device, comprising: a scanning unit; and a measuring standard having a measuring graduation, the scanning unit and the measuring standard being movable in relation to each other along at least one measuring direction; wherein the scanning unit includes a light source, a first annular scanning graduation, a reflector element, a beamsplitter element, and a detection unit; wherein a beam emitted by the light source impinges on the measuring graduation where it is split into at least two partial beams of rays; wherein the partial beams of rays propagate in a direction of the scanning unit impinging via the first scanning graduation on the reflector element; wherein the partial beams of rays are reflected by the reflector element in a direction of the measuring graduation and pass through the first scanning graduation on a path to the measuring graduation; wherein after impinging once more on the measuring graduation, the partial beams of rays propagating in a direction of the scanning unit undergo superposition and are deflected by the beamsplitter element in a direction of the detection unit, the detection unit adapted to record a plurality of positionally dependent, phase-shifted scanning signals; and wherein the first scanning graduation is adapted to induce a focusing of the partial beams of rays incident thereto from the measuring graduation at the reflector element and to thereby recollimate the partial beams of rays which, after being reflected at the reflector element, propagate in a direction of the measuring graduation.