Device for measuring the relative position of two objects

Abstract

A device for measuring the relative position of two objects by variation of capacitance. The device comprises a capacitive detector of the differential type which has at least two first electrodes adapted to be mechanically connected to one of the objects and at least a second electrode adapted to be mechanically connected to the other object and forming with the first electrodes two capacitances which vary as a function of the relative position of the objects. These two capacitances are in a ratio which is only a function of this relative position. There is provided a circuit for determining the values of these capacitances. The measuring device further comprises switching means for selectively connecting said capacitances to the input of said value determining circuit so as to measure successively said capacitances and also the parasitic capacitance inherent in the measuring system.

Dependencies are inferred from the claim text.