Optical position-measuring device

摘要

An optical position-measuring device is adapted to detect the position of an object in several spatial degrees of freedom. The object is disposed in a manner allowing it to move at least along a first direction of movement and along a second direction of movement. The position-measuring device includes at least one light source and at least one first and second measuring standard which are located on the object, extend along a first extension direction and a second extension direction and include graduation regions disposed periodically along the first and second extension directions. In addition, a scanning plate is provided, into which at least first and second retroreflector elements are integrated, the first retroreflector element extending parallel to the first extension direction and the second retroreflector element extending parallel to the second extension direction, and via which, sub-beams that fall on them from the first and second measuring standard, are reflected back in the direction of the respective measuring standard. From superposed sub-beams, a detector system is able to generate position signals at least with respect to the movement of the object along the first and second direction of movement.

主权项

1. An optical position-measuring device for detecting a position of an object in several degrees of freedom, the object being movable at least along a first direction of movement and along a second direction of movement, comprising:
at least one light source; at least one first measuring standard, arranged on the object, extending along a first extension direction and including graduation regions arranged periodically along the first extension direction; at least one second measuring standard, arranged on the object, which extending along a second extension direction and including graduation regions arranged periodically along the second extension direction; a single scanning plate, including integrated first and second retroreflector elements, a length direction of the first retroreflector element extending parallel to the first extension direction and a length direction of the second retroreflector element extending parallel to the second extension direction, the first and second retroreflector elements adapted to reflect back in a direction of a respective measuring standard sub-beams that fall on the first and second retroreflectors from the first and second measuring standards; and a detector system adapted to generate, from superposed sub-beams, at least position signals with respect to movement of the object along the first and second directions of movement; wherein the retroreflector elements are arranged as diffractive retroreflector elements, including: a plurality of diffractive elements provided on a first side of the scanning plate; and at least one reflector element that is provided on an opposite second side of the scanning plate and having a reflective side oriented in a direction of the diffractive elements, the reflector element extending parallel to the first extension direction or the second extension direction.