Patent ID: 9200927
Filing Date: 2015-12-01
Classification: G01D

Abstract:
1. A position-measuring device comprising: a cylindrical object rotatable about a longitudinal axis and having a circumferential annular reflection measuring graduation; a stationary scanning unit disposed opposite the cylindrical object and having a light source, a transmission grating and a detector, the scanning unit being configured to optically scan the reflection measuring graduation by beams of light emitted from the light source passing through the transmission grating and then striking the reflection measuring graduation, from where the beams of light are reflected back toward the detector, which is configured to generate rotation-dependent position signals, wherein an optically effective perpendicular distance between the detector and the reflection measuring graduation is selected to be one of greater or less than an optically effective perpendicular distance between the transmission grating and the reflection measuring graduation depending on a radius of the cylindrical object.