Method for determining a position of a contact on a capacitive sensor field
First Claim
1. A method of determining a position of a touch on a capacitive sensor field having a grid of a plurality of discrete electrodes (12), wherein:
- (a) touched electrodes are determined by measuring a capacitance value for each of the electrodes and checking for each of the electrodes for the measured capacitance value whether this value is above a predefined threshold value;
(b) a rough touch position (Bg) is calculated by weighting the electrode position with the measured capacitance value;
(c) a touch diameter (14) corresponding to a diameter of an area where a fingertip contacts two or more electrodes of the plurality of electrodes on a surface of the sensor field is calculated from each of the measured capacitance values; and
(d) a final touch position (Be) is calculated from the rough touch position (Bg) and the calculated touch diameter (14) using a value table in which correction values (k) that were determined empirically or by means of simulation and are dependent on the rough touch position (Bg) and the touch diameter (14) are stored for possible rough touch positions (Bg) and given touch diameters (14).
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Accused Products
Abstract
In a method of determining a position of a touch on a capacitive sensor field having a grid of a plurality of discrete electrodes (12), contacted electrodes are determined by measuring a capacitance value for each of the electrodes and by checking for each of the electrodes for the measured capacitance value whether this value is above a predefined threshold value. A rough touch position (Bg) is calculated by weighting the electrode position with the measured capacitance value. A touch diameter (14) is calculated from the measured capacitance values, and a final touch position (Be) is calculated from the rough touch position (Bg) and the calculated touch diameter (14) using a value table in which correction values that were determined empirically or by means of simulation are stored for possible rough touch positions (Bg) and given touch diameters (14).
5 Citations
11 Claims
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1. A method of determining a position of a touch on a capacitive sensor field having a grid of a plurality of discrete electrodes (12), wherein:
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(a) touched electrodes are determined by measuring a capacitance value for each of the electrodes and checking for each of the electrodes for the measured capacitance value whether this value is above a predefined threshold value; (b) a rough touch position (Bg) is calculated by weighting the electrode position with the measured capacitance value; (c) a touch diameter (14) corresponding to a diameter of an area where a fingertip contacts two or more electrodes of the plurality of electrodes on a surface of the sensor field is calculated from each of the measured capacitance values; and (d) a final touch position (Be) is calculated from the rough touch position (Bg) and the calculated touch diameter (14) using a value table in which correction values (k) that were determined empirically or by means of simulation and are dependent on the rough touch position (Bg) and the touch diameter (14) are stored for possible rough touch positions (Bg) and given touch diameters (14). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification