Andrews Kurth Kenyon LLP
Optical position-measuring device
An optical position-measuring device for detecting the position of two objects movable relative to each other includes a measuring standard that is joined to one of the two objects and has a measuring graduation having a periodic arrangement of graduation regions along at least a first graduation direction. The position-measuring device also includes a scanning unit having a plurality of optical elements, which is disposed in a manner allowing movement relative to the measuring standard. Via the arrangement and formation of the optical elements of the scanning unit, a scanning beam path results in which partial beams of rays reaching interference propagate in mirror symmetry in relation to a plane of symmetry and either fall in V-shaped fashion on the measuring standard and/or are reflected back in a V-shape by the measuring standard. The plane of symmetry is tilted by a defined tilt angle about an axis of rotation that is oriented parallel to the surface of the measuring standard and extends in a direction perpendicular to the first graduation direction.
DR. JOHANNES HEIDENHAIN GMBH
G G
G01D G01B
inventional inventional
Wolfgang
Holzapfel