Patent ID: 7956622

Claim:
A method for the signal processing of capacitive measurement scales, comprising: measuring a plurality of lengths or angles between two parts of the capacitive measurement scales, the two parts moving relative to each other, each of the two parts provided with electrodes that together form condensers, the magnitudes of which are variable and depend on the relative position as specified by a sinusoidal relationship between the two parts moving relative to each other, wherein the first part has n electrodes evenly distributed over one mechanical measurement period and the second part has one electrode per mechanical measurement period, and that the electrodes in the first part are supplied with n alternating input voltages of the same frequency and the same amplitude, wherein the time differences of the said alternating voltages relative to each other are t o /n, where t o is the length of the period of the said alternating voltage, whereby the electrode of the second mobile part captures in a capacitive manner a signal that comprises one or more of the said alternating voltages and where the amplitude of these signals depends on the relative position between the two parts; measuring the amplitude of each of the n signals in the electrodes of said second movable part; and storing separately the value for each of the n signals, wherein the relative position (x c ) is obtained through the algorithm: x c = { L 8 ⁢ π ⁡ [ π - 4 ⁢ ⁢ atan ⁡ [ Y X ] ] , ⁢  X  >  Y  L 8 ⁢ π ⁡ [ π + 4 ⁢ ⁢ atan ⁡ [ X Y ] ] , ⁢  X  ≤  Y  .