Abstract: In one embodiment, a touch sensor includes a touch screen having a plurality of electrodes and a controller. The controller is operable to detect that an object is in proximity to the touch screen by measuring capacitance values from a reference area of the touch screen, determining a reference capacitance value using the measured capacitance values from the reference area, measuring capacitance values from a main area of the touch screen, and suppressing noise from the measured capacitance values of the main area by subtracting the reference capacitance value from the measured capacitance values of the main area of the touch screen. The reference area includes two or more of the plurality of electrodes, and at least one of the electrodes of the reference area is electrically coupled to a voltage reference. The main area includes electrodes of the plurality of electrodes that are not in the reference area.

Abstract: In one embodiment, a method for changing the detection range of a touch sensor includes receiving a signal associated with an operation of a device having a touch sensor, and in response to the signal, determining that a detection mode of the touch sensor associated with the device is to be changed. In response to the determination, decreasing sensitivity of a portion, but not all, of the touch sensor.

Abstract: In one embodiment, a touch-sensitive device includes a controller, horizontal electrodes, and vertical electrodes. The touch-sensitive device further includes a first plurality of switches that couple the horizontal electrodes to a first plurality of sensors, a second plurality of switches that couple the vertical electrodes to a second plurality of sensors, and a third and fourth plurality of switches that couple the horizontal and vertical electrodes to a shield sensor. The controller is operable to perform simultaneous hovering, touch, and proximity detection by selectively controlling the first, second, third, and fourth plurality of switches. The hovering, touch, and proximity detection includes causing substantially equal voltages to be present on the horizontal and vertical electrodes while measuring capacitances using the shield sensor and either the first or second plurality of sensors.

Abstract: In one embodiment, an apparatus for detecting a touch. The apparatus includes a touch sensor that includes a first plurality of electrode lines and a second plurality of electrode lines. The apparatus also includes a touch sensor controller coupled to the touch sensor. The touch sensor controller is operable to apply a respective voltage pulse simultaneously to each of the first plurality of electrode lines, measure a respective signal at each of the second plurality of electrode lines, and detect a touch based on the measurement of the respective signals.