CPC G06F 3/0414 (2013.01) [G06F 3/0418 (2013.01); G06F 3/044 (2013.01)] | 20 Claims |
1. A method of processing signals from a touch panel which comprises a layer of piezoelectric material arranged between a plurality of first electrodes and at least one second electrode, the method comprising:
receiving one or more piezoelectric signals from the first electrodes, and correcting each piezoelectric signal to remove a first DC offset;
integrating the one or more corrected piezoelectric signals to determine respective force values;
maintaining a buffer storing buffer values, the buffer values corresponding to a preceding period;
determining whether one or more user interactions are occurring based on a gradient and a variance calculated for the buffer values; and
in response to determining that no user interactions are occurring, updating a second DC offset value; and
calculating corrected force values based on the force values and the second DC offset value.
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