Patent ID: 8736258

Claim:
Method for sensing rotation and angular position using a plurality of magnetic field sensing elements on a single integrated circuit and using a rotating movable magnetic target above or below this circuit wherein the magnetic field strength of this target shows a gradient in a first orientation axis orthogonal to the rotation axis and parallel to the integrated circuit's surface and does not show a significant gradient in the magnetic field strength along a second orientation axis that is orthogonal to the first orientation axis and parallel to the integrated circuit's surface comprising the tracking of the orientation and positioning with the steps: i. coarse determination of the orientation of the magnetic target relative to the sensing elements by combining signals of the plurality of magnetic field sensing elements a) arithmetically by summing signals out of a first combination of the sensing elements to derive an approximately sine signal representation of the actual magnetic target's orientation and where one 360° rotation of the magnetic target results in one sine wave cycle—and—summing signals out of a second combination of the sensing elements which intentionally derive a 90 degree shifted signal compared to the first of the magnetic target thus both combinations allow the angular calculation by deriving the arc tangent,—or b) logically by using comparators and window comparators to get a maximum value or alternatively a minimum value out of the summed signals of the sensor elements relative to the absolute orientation of the integrated circuit and using a predefined value table of at least some combinations of magnetic field sensing elements to define the angular difference, then ii. recombining the plurality of the magnetic field sensing elements arithmetically and/or logically in a suitable way conditioned of the results of step i. to get an improved signal since in this way the tracked orientation of the combination of the magnetic fielding sensing elements has the smallest angular distance to the orientation given by direction starting from the rotation centre of the magnetic target and pointing to the sensing place of the maximum magnetic gradient orthogonal to the rotation axis, and finally iii. computing a remaining misalignment of the magnetic target's orientation, with respect to the orientation of the chosen magnetic fielding sensing element or to a selected combination of magnetic fielding sensing elements.