Abstract: An embodiment of the invention provides a method of creating a statistical model of a baseline capacitance CP of a capacitive sensor located on a capacitive-touch screen. A sensed capacitance CS of a capacitive sensor is measured during a particular state of the electronic device that includes the capacitive-touch screen. When physical contact is not made with the capacitive sensor, the sensed capacitance CS is stored as a baseline capacitance CP. The baseline capacitance CP is then used to create the statistical model for that particular state of the electronic device. When physical contact is made with the capacitive sensor, the value of the baseline capacitance CP of the capacitive sensor is subtracted from the value of the sensed capacitance CS and the result, CF=(CS?CP), is sent to a touch detection circuit.

Abstract: An embodiment of the invention provides a method and apparatus for determining what type of interaction is made with a capacitive touch screen. A capacitance sensor with the largest sensed capacitance in a group of capacitance sensors is determined. Next, a parametric surface is determined from the value of the largest sensed capacitance and the values of the sensed capacitances in the group of capacitance sensors. From the parametric surface, an interpolated peak capacitance, a curvature K at the interpolated peak and an orientation ? at the interpolated peak are determined. Based on the interpolated peak capacitance, the curvature K and the orientation ?, the type of interaction made with the capacitive-touch screen is identified.

Abstract: An embodiment of the invention provides a method of creating a statistical model of a baseline capacitance CP of a capacitive sensor located on a capacitive-touch screen. A sensed capacitance CS of a capacitive sensor is measured during a particular state of the electronic device that includes the capacitive-touch screen. When physical contact is not made with the capacitive sensor, the sensed capacitance CS is stored as a baseline capacitance CP. The baseline capacitance CP is then used to create the statistical model for that particular state of the electronic device. When physical contact is made with the capacitive sensor, the value of the baseline capacitance CP of the capacitive sensor is subtracted from the value of the sensed capacitance CS and the result, CF=(CS?CP), is sent to a touch detection circuit.