Abstract: Embodiments are disclosed that relate to touch input detection in a touch sensor. One example provides a method comprising establishing a first reference sequence, starting with a first set of candidate reference sequences each differing from the first reference sequence, reducing the first set of candidate reference sequences by applying a rule set to the first set to derive a relatively smaller second set of candidate reference sequences, for each candidate reference sequence in the second set of candidate reference sequences, calculating a touch detection performance score of a combined reference sequence, and configuring at least a portion of a receive circuit to correlate signals to at least one of the touch detection conditions by using the first reference sequence in a combined correlation operation with at least a selected candidate reference sequence from the second set of candidate reference sequences.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for digital signal processing (DSP) techniques for generally improving a signal-to-noise ratio (SNR) of capacitive touch sensors.

Abstract: Systems and methods for transmitting information in interactive display systems are provided. In one example, an interactive display system comprises an interactive display including an electrode matrix, a display-side radio transceiver, and an input device including an electrode tip and an input device-side radio transceiver, wherein the interactive display is configured to communicate over an electrostatic link formed between the electrode matrix of the display and the electrode tip of the input device, wherein the input device is configured to detect a position signal, and to transmit data to the interactive display via a radio link, and wherein the input device is configured to sever the radio link and power down the input device-side radio transceiver if the input device has been separated from the interactive display by at least a threshold distance for at least a threshold duration.

Abstract: An active stylus includes an electrode and a controller. The controller is configured to 1) generate a report including stylus information represented by a plurality of bits including a first subset of bits and a second subset of bits, 2) encode the first set of bits differently than the second set of bits to reduce a size of the report, and 3) excite the electrode with a carrier signal to form an electrostatic communication channel, the carrier signal being modulated to transmit the report via the electrostatic communication channel.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for digital signal processing (DSP) techniques for generally improving a signal-to-noise ratio (SNR) of capacitive touch sensors.

Abstract: Embodiments are disclosed that relate to touch input detection in a touch sensor. One example provides a method comprising establishing a first reference sequence, starting with a first set of candidate reference sequences each differing from the first reference sequence, reducing the first set of candidate reference sequences by applying a rule set to the first set to derive a relatively smaller second set of candidate reference sequences, for each candidate reference sequence in the second set of candidate reference sequences, calculating a touch detection performance score of a combined reference sequence, and configuring at least a portion of a receive circuit to correlate signals to at least one of the touch detection conditions by using the first reference sequence in a combined correlation operation with at least a selected candidate reference sequence from the second set of candidate reference sequences.

Abstract: A touch-sensing system for use with a display system is provided herein. The touch-sensing system includes: (1) a first touch-sensor matrix having rows and columns and situated planarly relative to the display system; (2) a second touch-sensor matrix having rows and columns and situated planarly relative to the display system; and (3) a drive subsystem coupled to the rows of the first touch-sensor matrix and to the rows of the second touch-sensor matrix. Within each of a plurality of touch-sense frames, the drive subsystem serially drives the rows of each of the touch-sensor matrices in a differential drive manner, in which a first drive signal is used for the rows of the first touch-sensor matrix and a second drive signal, different from the first, is used for the rows of the second touch-sensor matrix.

Abstract: A discrete circuit multiplexing system in an interactive stylus is provided. The discrete circuit multiplexing system includes a first electrode and second electrode positioned in a stylus body, with a shared transmitting sub-system coupled to the first electrode and the second electrode. The circuit further includes a microcontroller configured to cause selective transmission of waveforms from the shared transmitting sub-system to the first electrode and the second electrode to selectively stimulate either the first electrode or the second electrode.

Abstract: Electrode matrices for capacitive touch-sensing are provided. An electrode matrix may include a plurality of column conductors having a first end and a second end formed along a central longitudinal axis. The column conductor may further include a column zigzag structure extending between the first end and the second end. The electrode matrix may further include a plurality of row conductors having a first end and a second end formed along a lateral axis. The row conductor may further include a row zigzag structure extending between the first end and second end. The zigzag structure of each of the plurality of column conductors may cross the zigzag structure of each of the plurality of row conductors in respective crossing regions that are formed at an intersection of the longitudinal axis of each column conductor and lateral axis of each row conductor.

Abstract: A touch display device includes a display panel, a plurality of receive electrodes, an enable electrode driver, and a touch sense circuit. The display panel includes a plurality of data electrodes and a plurality of enable electrodes connected to a plurality of display cells. Each display cell is connected to a pair of an enable electrode and a data electrode. The enable electrode driver drives a first enable electrode with a display voltage to activate display cells coupled to the first enable electrode, and drives a second enable electrode different than the first enable electrode with a transmit voltage to produce a capacitive coupling between the second enable electrode and a receive electrode. The touch sense circuit is configured to recognize a touch input to the touch display device based on a change in capacitance between the second enable electrode and the receive electrode.

Abstract: An interactive stylus for use with an interactive display device is provided. The interactive stylus includes a stylus body having a first end, where the first end is configured to be used by a user to provide a first function and a second function. The interactive stylus further includes a controller configured to cause the first end to be driven so as to capacitively couple the first end with an electrode matrix of the interactive display device, where such capacitive coupling is associated with the first function, and where the second function is disabled in response to automatically sensing, without explicit user input, a user's intent to use the first function.

Abstract: A touch-sensing system comprises an active stylus including a probe electrode and associated sensory logic. The sensory logic is configured to receive a synchronization pulse sequence via the probe electrode between consecutive touch-sensing frames of a capacitive touch screen, to use the synchronization pulse sequence to synchronize a local row counter of the sensory logic to a remote row counter of the capacitive touch screen, to receive an excitation pulse via the probe electrode within a given touch-sensing frame, and to use the excitation pulse to maintain synchronization between the local row counter and the remote row counter.

Abstract: A discrete circuit multiplexing system in an interactive stylus is provided. The discrete circuit multiplexing system includes a first electrode and second electrode positioned in a stylus body, with a shared transmitting sub-system coupled to the first electrode and the second electrode. The circuit further includes a microcontroller configured to cause selective transmission of waveforms from the shared transmitting sub-system to the first electrode and the second electrode to selectively stimulate either the first electrode or the second electrode.

Abstract: Systems are described for transmitting and receiving signals in an active stylus for a capacitive touch sensor, for which the systems have at least one circuit for receiving a current from an electrode and for transmitting a voltage onto the electrode. The systems include components for receiving the current in a receiving mode, a switch, and a switchmode power supply circuit having at least a transformer and a diode, for which the diode is coupled to the transformer. In a transmission mode, there is means for electrically isolating at least some of the components configured for receiving the current in the receiving mode from the voltage formed across the stray capacitance. In the receiving mode, there is a means for electrically isolating at least some of the components configured for receiving the current in the receiving mode from an inductance of the transformer in the switchmode power supply circuit.

Abstract: Systems and methods for transmitting information in interactive display systems are provided. In one example, an interactive display system comprises an interactive display including an electrode matrix having row and column electrodes, the row electrodes being sequentially driven, a display-side radio transceiver, and an input device including an electrode tip and an input device-side radio transceiver. The interactive display is configured to transmit a channel identifier in an electrostatic link formed between the electrode matrix of the display and the electrode tip of the input device, and the input device is configured to detect a position signal indicating a nearest row electrode in the electrode matrix adjacent which the electrode tip is positioned, and to transmit data indicating the nearest row electrode to the interactive display via a radio link between the input device side transceiver and the display side transceiver on a channel identified by the channel identifier.

Abstract: Embodiments are disclosed herein that are related to input devices with curved multi-touch surfaces. For example, in one disclosed embodiment, a method of making a multi-touch input device having a curved touch-sensitive surface comprises forming on a substrate an array of sensor elements defining a plurality of pixels of the multi-touch sensor, forming the substrate into a shape that conforms to a surface of the curved geometric feature of the body of the input device, and fixing the substrate to the curved geometric feature of the body of the input device.

Abstract: Methods, systems, and apparatus relate to touch sensors that are configured to measure input applied to the sensor from a user. Some implementations involve the measurement of changes in capacitance between pairs of adjacent patterned electrodes to detect input at a touch sensor.

Abstract: Methods, systems, and apparatus relate to capacitive touch sensors with a fine-pointed, active stylus. The active stylus is configured to receive a signal from the capacitive touch sensor for synchronizing a time base of the stylus with the capacitive touch sensor. The active stylus is configured to receive a signal from a matrix of the capacitive touch sensor to measure a first position along one axis, and transmit a signal from the single electrode of the stylus to the matrix to indicate a second position of the stylus along another axis of the matrix. The stylus can transmit the received signal to report the first position of the stylus.

Abstract: To address the above issues, a display device with a capacitive touch screen display having a touch surface in close proximity to a display stack is provided. The display may include a touch sheet with a top surface, a touch sensor having a matrix of capacitors formed of electrodes positioned below the touch sheet and configured to exhibit a change in capacitance of at least one of the capacitors in response to a touch on the top surface by a digit or stylus of a user, a display stack positioned below the matrix of capacitors and configured to emit light through a top surface of the display stack to travel in a light emitting direction through the matrix of capacitors and the touch sheet. A distance between the top surface of the touch sheet and the top surface of the display stack is between about 225 and 1500 micrometers.

Abstract: Systems are described for transmitting and receiving signals in an active stylus for a capacitive touch sensor, for which the systems have at least one circuit for receiving a current from an electrode and for transmitting a voltage onto the electrode. The systems include components for receiving the current in a receiving mode, a switch, and a switchmode power supply circuit having at least a transformer and a diode, for which the diode is coupled to the transformer. In a transmission mode, there is means for electrically isolating at least some of the components configured for receiving the current in the receiving mode from the voltage formed across the stray capacitance. In the receiving mode, there is a means for electrically isolating at least some of the components configured for receiving the current in the receiving mode from an inductance of the transformer in the switchmode power supply circuit.