Device for determining the location or the variation in location of a position encoder

摘要

The invention proposes a device for determining the location or the change in location of a position encoder which produces at a sensor arrangement signals dependent on the location of the position encoder, in which an essentially two-dimensional arrangement of the placing of the sensors is possible. This is achieved by means of an arrangement of four sensors having the same characteristic, which are placed at the four corner points of a plane rectangle with mutually identical geometrical alignment, and of an evaluation circuit for the signals transmitted by the sensors under the influence of the location of the position encoder, in which evaluation circuit the change, depending on the distance of the position encoder from the plane of the rectangle, of the sensor signals is used as a measure of this distance and as a drive signal for a correction element which, for its part, drives transconductance amplifiers which compensate the influence of the variation in location of the position encoder in the z-direction on the change in the two sum signals from the signals of the sensors in such a way that signals proportional to the x- or y-coordinates of the position encoder are obtained from these two sum signals.