Patent ID: 8242774
Filing Date: 2012-08-14
Classification: G01D

Abstract:
1. Incremental displacement transducer for determining a displacement of a first object relative to a second object, having a scanning unit linked or to be linked with the first object for scanning a spacing track linked or to be linked with the second object and having first areas and second areas arranged in alternating manner with a period length, the first areas having a first physical property and the second areas a second physical property differing therefrom and the scanning unit has a plurality of sensors for scanning the first areas and the second areas on the basis of at least one of the first and the second physical property, each sensor yielding a separate measuring signal, each measuring signal being measured separately, and having an evaluation unit linked with the scanning unit for determining the displacement on the basis of the measuring signals of the sensors, wherein the scanning unit has eight sensors, which are spaced from one another over at least one period length of the spacing track in such a way that the measuring signals of adjacent sensors and of sensors spaced by another sensor overlap, at least one first switching signal is generated from the eight separate measuring signals of the sensors in the evaluation unit for the determination of the displacement, the first switching signal assumes a first value if the measuring signal of a first selected sensor of a first subgroup of sensors assumes a maximum value within the first subgroup and simultaneously the measuring signal of a second selected sensor of a second subgroup of sensors assumes a maximum value within the second subgroup, and the first switching signal otherwise assumes a second value, each subgroup comprising at least two sensors, and wherein there is at least one further sensor between the sensors forming a subgroup.