Patent ID: 8477317

Claim:
A position measuring arrangement for determining the position of a spatial point, the position measuring arrangement comprising: a retroreflector; a light source generating a lightbeam; a scanning unit that receives said lightbeam and generates a partially-divergent lightbeam, wherein said partially-divergent lightbeam is defined to have a beam divergence that lies between a minimal divergence of an ideally collimated lightbeam and a maximal divergence of a fully-divergent lightbeam, wherein said scanning unit comprises: a scanning mirror that is mounted so it is deflected in a reproducible manner around two different rotating axes that cross each other in a center of said scanning mirror so that a grid-like scanning of a two-dimensional spatial area by said partially-divergent lightbeam, in relation to which said retroreflector is arranged, takes place over a plurality of scanning tracks, wherein either 1) said retroreflector is arranged in a stationary manner in said spatial area, and said scanning unit is arranged in an area of a spatial point, or 2) said scanning unit is arranged in a stationary manner in said spatial area, and said retroreflector in said area of said spatial point; an interferometric distance measuring unit comprising: a beam splitter element that splits said lightbeam generated by said light source in such a way that split lightbeams pass through a reference arm and a measuring arm at least once in each direction, and wherein said measuring arm is formed in said area of said spatial point in which said partially-divergent lightbeam is propagated by said scanning unit in a direction of said retroreflector and back; an opto-electronic detector unit, through which a detection of distance-dependent signals from superimposed lightbeams from said reference arm and said measuring arm at a time of optical contact between said scanning unit and said retroreflector, a back reflection of said lightbeam from said retroreflector in a direction of said scanning unit results.