Patent ID: 7435940

Claim:
A system for determining a position of an element emitting/reflecting electromagnetic radiation, the emitting/reflecting element contacts a radiation transmissive element and emits/reflects radiation into the radiation transmissive element, the system comprising: an at least one-dimensional detector having a row of a plurality of individual elements each being adapted to detect radiation and to provide a corresponding signal, a first elongated radiation transforming element provided on a surface of the radiation transmissive element so that radiation from the emitting/reflecting element travels inside the radiation transmissive element on a radiation path from the emitting/reflecting element to the detector, the first radiation transforming element being arranged in the radiation path and being adapted to modulate electromagnetic radiation from the emitting/reflecting element so as to form a modulated radiation intensity pattern on a row of the detector, and a determining element adapted to determine, on the basis of the intensity pattern detected by the detector, a position of the emitting/reflecting element.