Magnetic encoder apparatus having a plurality of magnetic sensor elements

Magnetic encoder apparatus comprising:

• a plurality of magnetic sensor elements for reading an associated magnetic scale that produces a periodically repeating magnetic pattern, the plurality of magnetic sensor elements producing a plurality of sensor signals;
• an analyser for analyzing the plurality of sensor signals to provide a measure of the position of the magnetic sensor elements relative to the associated magnetic scale;
• the analyser being arranged to use the plurality of sensor signals to assess the period of the periodically repeating magnetic pattern sensed by the plurality of magnetic sensor elements;
• and
• the magnetic scale having a series of alternating firs magnetized regions and second magnetized regions, wherein:
• the first magnetized regions are of the opposite magnetic pole to the second magnetized regions,
• centers of the first magnetized regions are spaced apart from one another by a fixed interval such that a distance between neighboring centers of each of the first magnetized regions is the same, and
• each first magnetized region has a first width or a second different width and thereby encodes a data bit, the data bit taking a first value if the first magnetized region has the first width and a different second value if the first magnetized region has the second width.