Method and device for redundant distance measurement and mismatch cancellation in phase-measurement systems

摘要

The method serves for canceling errors caused by mismatch of different signal paths in a photodetector with a plurality (k) of storage elements for the photogenerated signals, as typically used in phase-measurement systems. The signal-capturing process is performed in at least two measurement cycles (j). A first cycle (j = 1) is executed with the conventional setup with no phase delay in the control signals. It is followed by further measurement cycles (j = 2, 3, 4) which use control signals shifted by a constant phase shift (90°). Corresponding signals are read out through different signal paths. At the end, the signals corresponding to a certain phase (¦) are added, thus canceling possible offset values.