Patent ID: 8233153

Claim:
Position detection system for contactless interferometic detection of a location of a target object, comprising a target object unit, and a measuring light transmitter unit with at least one measuring light transmitter from which a measuring light beam with coherent light is radiated onto the target object unit; wherein the location of the target object unit is determined using interferometric measuring data obtained from interference signals which are generated by a detector due to the interference of the measuring light beam with a reference light beam, which is coherent with the measuring light beam; the target object unit comprises a reference light transmitter, which is configured for transmitting the reference light beam with curved light wave fronts; the target object unit comprises at least one detector array having a plurality of detector pixels, the detector array being fixed to the target object unit for impinging the reference light beam of the reference light transmitter on the detection array, wherein the wave fronts of the measuring light beam impinge onto the detector array of the target object unit with a curvature which is less than the curvature of the wave fronts of the reference light beam; the wave fronts of the measuring light beam and of the reference light beam impinge only onto a portion of the detector pixels of the detector array with a sufficiently parallel orientation to allow the generation of an interference signal in the detector pixel; interference signals of at least one interference-signal-generating detector pixel of the detector array are evaluated to determine distance information about changes of the distance between the respective detector pixel and the measuring light transmitter, and the location of the target object relative to the measuring light transmitter unit is determined using this distance information.