Patent ID: 8526014

Claim:
A positioning device, comprising: a detector for detecting light of a fan shaped laser beam rotating around a propagation axis with a direction of rotation and having at least two detector elements (A, B) arranged in a known spatial relation to one another for outputting a detection signal when irradiated by the fan shaped laser beam; and a position determining unit adapted to obtain a first set of detection signals from the detector elements wherein the first set of detection signals is obtained from detector elements arranged along a first line, determine at least one first time relation between the detection signals of the first set, determine a positional relation between the detector and the propagation axis based on the first time relation, obtain a second set of detection signals from detector elements arranged along a second line, the first and second lines not being parallel with respect to one another, determine at least one second time relation between the detection signals of the second set, determine a repetition time interval between two detection signals from the same detector element and to determine an angular velocity (ω) of the fan shaped laser beam based thereon, determine a first time interval between the detection signals of the first set and a second time interval between the detection signals of the second set, determine, based on the angular velocity of the fan shaped laser beam and the first and second time intervals of a plurality of detector elements, two angles between the detector elements, and determine, based on the two detector element angles and the spatial relation of the detector elements, a distance of the detector to the propagation axis.