Patent ID: 7714273
Filing Date: 2010-05-11
Classification: G01D

Abstract:
1. A position-measuring device for generating a reference-pulse signal at at least one reference position, comprising: a scanning unit; and a reflection-measuring graduation displaceable relative to the scanning unit in at least one measuring direction; wherein the scanning unit, to generate the reference-pulse signal, includes a plurality of optical elements including at least one imaging optics and at least two diaphragm structures disposed in a diaphragm plane and having a plurality of diaphragm openings, a light source and at least two detector elements being assigned to the scanning unit; wherein the reflection-measuring graduation includes a reference marking at the at least one reference position; wherein the reference marking includes at least one set of first structure elements disposed in a plane of the reflection measuring graduation, perpendicular to the measuring direction, periodically at a first transversal periodicity, the reference marking including at least one set of second structure elements disposed in the plane of the reflection measuring graduation, perpendicular to the measuring direction, periodically at a second transversal periodicity, the first transversal periodicity and the second transversal periodicity differing from each other; and wherein the structure elements are arranged as diffractive structure elements which are configured to optically act, in the measuring direction, as a cylinder lens having a specific focal length and, perpendicular to the measuring direction, act as a deflecting grating having one of (a) the first transversal periodicity and (b) the second transversal periodicity.