Abstract: A touch screen controller is for a drive line emitting a periodic signal and capacitively intersecting sense lines. A selection circuit, for each of a number of portions of the periodic signal equal to a number of the sense lines, couples a first subset of the sense lines to a first output path, and couples a second subset of the sense lines to a second output path, the second subset being sense lines not included in the first subset. Processing circuitry, for each portion of the periodic signal, measures a capacitance of the first output path, measures a capacitance of the second output path, and sums the capacitance of the first output path and the capacitance of the second output path. The processing circuitry determines a capacitance between each sense line of the first and second subsets and the drive line as a function of the sums.

Abstract: An active stylus is capacitively coupled to a capacitive touch panel for communication. The active stylus operates in a wait mode to receive initial communications from the panel. In response to such receipt, the active stylus synchronizes to a repeating communications frame implementing time division multiplexing. Communications from the active stylus to the panel include: information communications; synchronization communications and communications specific for columns and/or rows of the panel. Communications from the panel to the active stylus may be addressed uniquely to the stylus or commonly to a group of styluses.

Abstract: An active stylus is capacitively coupled to a capacitive touch panel for communication. The active stylus operates in a wait mode to receive initial communications from the panel. In response to such receipt, the active stylus synchronizes to a repeating communications frame implementing time division multiplexing. Communications from the active stylus to the panel include: information communications; synchronization communications and communications specific for columns and/or rows of the panel. Communications from the panel to the active stylus may be addressed uniquely to the stylus or commonly to a group of styluses.

Abstract: A touch screen device having a touch screen panel and a method for operating a touch screen device are provided. The method includes monitoring, during a noise monitoring phase, channel signals of a first set of channels and a second set of channel of the touch screen panel, detecting a stylus signal in response to a channel signal greater than a stylus threshold and less than a palm threshold, selecting the first set of channels when the stylus signal is detected on at least one channel of the first set of channels and is not detected on the second set of channels, and selecting the second set of channels when the stylus signal is detected on at least one channel of the second set of channels and is not detected on the first set of channels.

Abstract: An active stylus is capacitively coupled to a capacitive touch panel for communication. The active stylus operates in a wait mode to receive initial communications from the panel. In response to such receipt, the active stylus synchronizes to a repeating communications frame implementing time division multiplexing. Communications from the active stylus to the panel include: information communications; synchronization communications and communications specific for columns and/or rows of the panel. Communications from the panel to the active stylus may be addressed uniquely to the stylus or commonly to a group of styluses.

Abstract: A touch panel includes capacitive sensing electrodes and a touch controller operates in a first operating mode to detect a touch location on the touch panel. In a second operating mode, the touch controller transmits a modulated data signal through the touch panel to an active stylus. Each electrode is driven by a line driver circuit. A control circuit selectively actuates first ones of the line driver circuits to pass the modulated data signal to corresponding first ones of the electrodes which do not pass through a region of the touch panel associated with the location of the detected touch. Simultaneously, the control circuit selectively actuates second ones of the line driver circuits, different from said first ones of the line driver circuits, to ground corresponding second ones of the electrodes which do pass through the region of the touch panel associated with the location of the detected touch.

Abstract: An electronic device may include a first controller associated with some channels of a digitizer having channels configured to receive a signal from a stylus, and with each channel having a direction. A second controller may be associated with channels of the digitizer not associated with the first controller. The first controller may scan for the signal at each channel associated with the first controller, and based on acquisition of the signal at a given channel associated with the first controller, calculate a property of the signal. The first controller may send the calculated property and the direction of the given channel to the second controller. The first controller and the second controller may scan for the signal at each channel having the direction of the given channel, at acquisition intervals based upon the calculated property.

Abstract: A touch screen controller is for a drive line emitting a periodic signal and capacitively intersecting sense lines. A selection circuit, for each of a number of portions of the periodic signal equal to a number of the sense lines, couples a first subset of the sense lines to a first output path, and couples a second subset of the sense lines to a second output path, the second subset being sense lines not included in the first subset. Processing circuitry, for each portion of the periodic signal, measures a capacitance of the first output path, measures a capacitance of the second output path, and sums the capacitance of the first output path and the capacitance of the second output path. The processing circuitry determines a capacitance between each sense line of the first and second subsets and the drive line as a function of the sums.

Abstract: A touch panel includes capacitive sensing electrodes and a touch controller operates in a first operating mode to detect a touch location on the touch panel. In a second operating mode, the touch controller transmits a modulated data signal through the touch panel to an active stylus. Each electrode is driven by a line driver circuit. A control circuit selectively actuates first ones of the line driver circuits to pass the modulated data signal to corresponding first ones of the electrodes which do not pass through a region of the touch panel associated with the location of the detected touch. Simultaneously, the control circuit selectively actuates second ones of the line driver circuits, different from said first ones of the line driver circuits, to ground corresponding second ones of the electrodes which do pass through the region of the touch panel associated with the location of the detected touch.

Abstract: An electronic device may include a first controller associated with some channels of a digitizer having channels configured to receive a signal from a stylus, and with each channel having a direction. A second controller may be associated with channels of the digitizer not associated with the first controller. The first controller may scan for the signal at each channel associated with the first controller, and based on acquisition of the signal at a given channel associated with the first controller, calculate a property of the signal. The first controller may send the calculated property and the direction of the given channel to the second controller. The first controller and the second controller may scan for the signal at each channel having the direction of the given channel, at acquisition intervals based upon the calculated property.

Abstract: An active stylus is capacitively coupled to a capacitive touch panel for communication. The active stylus operates in a wait mode to receive initial communications from the panel. In response to such receipt, the active stylus synchronizes to a repeating communications frame implementing time division multiplexing. Communications from the active stylus to the panel include: information communications; synchronization communications and communications specific for columns and/or rows of the panel. Communications from the panel to the active stylus may be addressed uniquely to the stylus or commonly to a group of styluses.

Abstract: A touch screen device having a touch screen panel and a method for operating a touch screen device are provided. The method includes monitoring, during a noise monitoring phase, channel signals of a first set of channels and a second set of channel of the touch screen panel, detecting a stylus signal in response to a channel signal greater than a stylus threshold and less than a palm threshold, selecting the first set of channels when the stylus signal is detected on at least one channel of the first set of channels and is not detected on the second set of channels, and selecting the second set of channels when the stylus signal is detected on at least one channel of the second set of channels and is not detected on the first set of channels.