Abstract: Apparatuses and methods of multi-phase scanning of a touch panel are described. One apparatus selects a sequence having a number of one values, negative one values, and zero values. The one values correspond to an in-phase drive signal, the negative one values correspond to an opposite-phase drive signal, and the zero values correspond to a reference signal (e.g., reference voltage or ground). A sum of the sequence is equal to zero. The apparatus applies one of the in-phase drive signal, the opposite-phase drive signal, or the reference signal to each of a first set of electrodes at a first stage according to the sequence. The apparatus rotates the sequence to obtain a rotated sequence and applies one of the signals according to the rotated sequence. The apparatus receives sense signals to detect a presence of an object on the touch panel.

Abstract: Apparatuses and methods of multi-phase scanning of a touch panel are described. One apparatus selects a sequence having a number of one values, negative one values, and zero values. The one values correspond to an in-phase drive signal, the negative one values correspond to an opposite-phase drive signal, and the zero values correspond to a reference signal (e.g., reference voltage or ground). A sum of the sequence is equal to zero. The apparatus applies one of the in-phase drive signal, the opposite-phase drive signal, or the reference signal to each of a first set of electrodes at a first stage according to the sequence. The apparatus rotates the sequence to obtain a rotated sequence and applies one of the signals according to the rotated sequence. The apparatus receives sense signals to detect a presence of an object on the touch panel.

Abstract: A method, apparatus, and system measure, at a first channel of a processing device, a first signal indicative of a touch object proximate to an electrode layer. The first signal includes a touch data component and a first noise component generated by a noise source. The method, apparatus, and system measure, at a second channel of the processing device, a second signal including a second noise component generated by the noise source. The second channel is coupled to a shield layer disposed between the noise source and the electrode layer. The method, apparatus, and system generate an estimated noise signal using the second noise component of the second signal that is associated with the second channel. The method, apparatus, and system subtract the estimated noise signal from the measured first signal to obtain the touch data component of the first signal.

Abstract: A method, apparatus, and system measure, at a first channel of a processing device, a first signal indicative of a touch object proximate to an electrode layer. The first signal includes a touch data component and a first noise component generated by a noise source. The method, apparatus, and system measure, at a second channel of the processing device, a second signal including a second noise component generated by the noise source. The second channel is coupled to a shield layer disposed between the noise source and the electrode layer. The method, apparatus, and system generate an estimated noise signal using the second noise component of the second signal that is associated with the second channel. The method, apparatus, and system subtract the estimated noise signal from the measured first signal to obtain the touch data component of the first signal.

Abstract: A method, apparatus, and system measure, at a first channel of a processing device, a first signal indicative of a touch object proximate to an electrode layer. The first signal includes a touch data component and a first noise component generated by a noise source. The method, apparatus, and system measure, at a second channel of the processing device, a second signal including a second noise component generated by the noise source. The second channel is coupled to a shield layer disposed between the noise source and the electrode layer. The method, apparatus, and system generate an estimated noise signal using the second noise component of the second signal that is associated with the second channel. The method, apparatus, and system subtract the estimated noise signal from the measured first signal to obtain the touch data component of the first signal.

Abstract: A capacitance sensing device includes a transmit (TX) generator for generating a sequence of receive (RX) signals by applying each TX signal pattern in a sequence of TX signal patterns to a set of sensor electrodes. For each TX signal pattern in the sequence of TX signal patterns, and for each subset of three or more contiguous sensor electrodes of the set of sensor electrodes, the TX generator applies to the subset one of a first excitation signal and a second excitation signal. The plurality of subsets includes at least half of the sensor electrodes in the set of sensor electrodes. The capacitance sensing device also includes a sequencer circuit coupled with the TX generator. For each TX signal pattern in the sequence of TX signal patterns, the sequencer circuit determines a next subsequent TX signal pattern in the sequence based on a circular rotation of the TX signal pattern. The capacitance sensing device also includes a processing block coupled with the TX generator.

Abstract: A method, apparatus, and system measure, at a first channel of a processing device, a first signal indicative of a touch object proximate to an electrode layer. The first signal includes a touch data component and a first noise component generated by a noise source. The method, apparatus, and system measure, at a second channel of the processing device, a second signal including a second noise component generated by the noise source. The second channel is coupled to a shield layer disposed between the noise source and the electrode layer. The method, apparatus, and system generate an estimated noise signal using the second noise component of the second signal that is associated with the second channel. The method, apparatus, and system subtract the estimated noise signal from the measured first signal to obtain the touch data component of the first signal.

Abstract: A capacitance sensing system can filter noise that presents in a subset of electrodes in the proximity of a sense object (i.e., finger). A capacitance sensing system can include a sense network comprising a plurality of electrodes for generating sense values; a noise listening circuit configured to detect noise on a plurality of the electrodes; and a filtering circuit that enables a filtering for localized noise events when detected noise values are above one level, and disables the filtering for localized noise events when detected noise values are below the one level.

Abstract: An apparatus includes a transmission system configured to transmit a drive signal to a touch screen device. The apparatus also includes a reception system configured to integrate an output signal received from a touch screen device in response to the drive signals and to filter the integrated output signal to suppress noise in the output signal, wherein the reception system is configured to integrate the output signal for a period of time that is less than or equal to a signal period corresponding to the drive signal.

Abstract: A processing device performs a first scan of a first plurality of electrodes along a first axis in a capacitive sense array to generate a first plurality of capacitance values corresponding to a mutual capacitance at electrode intersections of the capacitive sense array. The processing device performs a second scan of a second plurality of electrodes along a second axis in the capacitive sense array to generate a second plurality of capacitance values corresponding to the mutual capacitance at the electrode intersections of the capacitive sense array. The processing device determines a first coordinate of a conductive object proximate to the capacitive sense array based on the a first subset of first plurality of signals and a second coordinate of the conductive object based on a second subset of the second plurality of signals.

Abstract: Capacitive touch sensors and touchscreen data processing methods are provided. In one embodiment, the method includes sequentially integrating and converting charge from each of a plurality of sensing capacitors in an array to digital data, the digital data including sample values corresponding to a measured capacitance for each of the plurality of sensing capacitors. Noise is then separated from useful information by filtering the sample values on a sample-by-sample basis. Finally, the filtered sample values are summed and a position of at least one contact on the array determined using the filtered capacitance values. Other embodiments are also provided.

Abstract: A capacitance sensing system can filter noise that presents in a subset of electrodes in the proximity of a sense object (i.e., finger). A capacitance sensing system can include a sense network comprising a plurality of electrodes for generating sense values; a noise listening circuit configured to detect noise on a plurality of the electrodes; and a filtering circuit that enables a filtering for localized noise events when detected noise values are above one level, and disables the filtering for localized noise events when detected noise values are below the one level.

Abstract: Apparatuses and methods of frequency selection algorithms and frequency set selection are described. One method monitors a signal on the electrodes of a sense network, determine a first group of noise metrics of noise in the signal, determine a second group of noise metrics. The method switches from a first operating frequency in a first set to a second operating frequency in the first frequency set based on the first group of noise metrics and switches from the first operating frequency in the first set to a third operating frequency in a second frequency set based on the second group of noise metrics.

Abstract: A capacitance sensing system can filter noise that presents in a subset of electrodes in the proximity of a sense object (i.e., finger). A capacitance sensing system can include a sense network comprising a plurality of electrodes for generating sense values; a noise listening circuit configured to detect noise on a plurality of the electrodes; and a filtering circuit that enables a filtering for localized noise events when detected noise values are above one level, and disables the filtering for localized noise events when detected noise values are below the one level.

Abstract: A processing device performs a first scan of a first plurality of electrodes along a first axis in a capacitive sense array to generate a first plurality of capacitance values corresponding to a mutual capacitance at electrode intersections of the capacitive sense array. The processing device performs a second scan of a second plurality of electrodes along a second axis in the capacitive sense array to generate a second plurality of capacitance values corresponding to the mutual capacitance at the electrode intersections of the capacitive sense array. The processing device determines a first coordinate of a conductive object proximate to the capacitive sense array based on the a first subset of first plurality of signals and a second coordinate of the conductive object based on a second subset of the second plurality of signals.

Abstract: A processing device performs a first scan of a first plurality of electrodes along a first axis in a capacitive sense array to generate a first plurality of capacitance values corresponding to a mutual capacitance at electrode intersections of the capacitive sense array. The processing device performs a second scan of a second plurality of electrodes along a second axis in the capacitive sense array to generate a second plurality of capacitance values corresponding to the mutual capacitance at the electrode intersections of the capacitive sense array. The processing device determines a first coordinate of a conductive object proximate to the capacitive sense array based on the a first subset of first plurality of signals and a second coordinate of the conductive object based on a second subset of the second plurality of signals.

Abstract: An apparatus includes a transmission system configured to transmit a drive signal to a touch screen device. The apparatus also includes a reception system configured to integrate an output signal received from a touch screen device in response to the drive signals and to filter the integrated output signal to suppress noise in the output signal, wherein the reception system is configured to integrate the output signal for a period of time that is less than or equal to a signal period corresponding to the drive signal.

Abstract: A capacitance sensing system can filter noise that presents in a subset of electrodes in the proximity of a sense object (i.e., finger). A capacitance sensing system can include a sense network comprising a plurality of electrodes for generating sense values; a noise listening circuit configured to detect noise on a plurality of the electrodes; and a filtering circuit that enables a filtering for localized noise events when detected noise values are above one level, and disables the filtering for localized noise events when detected noise values are below the one level.