Capacitive touch pad configured for proximity detection

摘要

The present disclosure relates to a method for controlling a touch pad, comprising an object locate mode for locating an object on the touch pad comprising steps of: determining a measurement of capacitance of each of the pairs of electrodes of the touch pad, each pair comprising a row electrode and a column electrode transverse to the row electrode, comparing each measurement with a first detection threshold, and if the comparison of at least one measurement with the first threshold reveals the presence of an object on the touch pad, locating the object on the touch pad according to the capacitance measurements, the method comprising a proximity detection mode comprising steps of: determining a measurement representative of the capacitance between one or two electrodes and one or two other electrodes of the touch pad, and comparing a measurement obtained with a second detection threshold different from the first threshold.

主权项

1. A device, comprising:
a touch pad, having a plurality of row electrodes that each extend from a top side to a bottom side of the touch pad and a plurality of column electrodes that are transverse to the row electrodes, the plurality of column electrodes each extend from a left side to a right side of the touch pad; an object detection circuit operable in an object locate mode and a proximity detection mode, wherein:
in the object locate mode, the object detection circuit:activates a first pair of electrodes, a first one of the first pair being one of the row electrodes and a second one of the first pair being one of the column electrodes;determines a first capacitance between the first pair of electrodes to determine a location of an object on the touch pad;in the proximity detection mode, the object detection circuit:activates simultaneously a second pair of electrodes, a first one of the second pair being one of the row electrodes and a second one of the second pair being a different one of the row electrodes, the different one of the row electrodes being spaced from the one of the row electrodes by at least one other row electrode; anddetermines a second capacitance between the second pair of electrodes to determine if an object is within a proximity of the touch pad.