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: An apparatus and method for detecting the angle of passive rotary knob partially located on a touch screen are described. In embodiments the apparatus includes a touch screen having an array of sensors and a dial that includes a base and a knob attached to the base and rotatable relative to the base. The knob includes a plurality of conductive elements, each positioned a distance from a center point of the knob. A controller is also included, coupled to the touch screen, and configured to receive signals generated by one or more sensors of the array in response to the sensors detecting one or more of the conductive elements. The controller can determine a rotational angle of the knob based on the signals generated by the one or more of the sensors in the array while a portion of the knob does not overlap the array of sensors.

Abstract: A touch screen device is disclosed. The touch screen device includes a touch screen panel having a capacitive sense array, and a passive dial including first, second and third conductive parts. The first conductive part and the third conductive part are in proximity to a surface of the touch screen panel, and the second conductive part is conductively coupled to the third conductive part when the passive dial is pressed and is not conductively coupled to the third conductive part when the passive dial is not pressed. A position of the first conductive part above the capacitive sense array corresponds to a touch index in the capacitive sense array and a position the third conductive part above the capacitive sense array corresponds to a button press index in the capacitive sense array. The first, second and third conductive parts are movable in conjunction with a rotation of the passive dial.

Abstract: Systems, methods, and devices detect defects in touch panels. Methods include scanning, using a designated integration window, a plurality of electrodes of a sensing device to obtain a plurality of measurements and determining a plurality of variance values for the plurality of electrodes based on the plurality of measurements, the plurality of variance values identifying variances in the plurality of measurements between adjacent sense locations of the sensing device. Methods also include determining if a defect is present in the sensing device based, at least in part, on a comparison of the plurality of difference values with the plurality of threshold values.

Abstract: Apparatuses and methods of quadrature modulation and compensation are described. One touch controller includes a receiver sensing channel to measure a sense signal and generate at least four samples per one period of the sense signal. The touch controller includes quadrature demodulation logic to determine phase information of the sense signal using the at least four samples per one period of the sense signal and processing logic to execute a compensation algorithm to compensate for a phase mismatch of the touch controller based on the phase information.

Abstract: Systems, methods, and devices improve the sensitivity of capacitive sensors. Devices may include an attenuator configured to receive an input from at least one sense electrode of a capacitive sensing device. The attenuator may be included in a sensing channel of a capacitive sensor. Devices may further include a signal generator coupled to an input of the attenuator. The signal generator may include one or more processors configured to generate a sinusoidal signal based, at least in part, on one or more noise characteristics of a scan sequence associated with one or more transmit electrodes of the capacitive sensing device, and provide the sinusoidal signal to the input of the attenuator.

Abstract: An apparatus and method for detecting the angle of passive rotary knob partially located on a touch screen are described. In embodiments the apparatus includes a touch screen having an array of sensors and a dial that includes a base and a knob attached to the base and rotatable relative to the base. The knob includes a plurality of conductive elements, each positioned a distance from a center point of the knob. A controller is also included, coupled to the touch screen, and configured to receive signals generated by one or more sensors of the array in response to the sensors detecting one or more of the conductive elements. The controller can determine a rotational angle of the knob based on the signals generated by the one or more of the sensors in the array while a portion of the knob does not overlap the array of sensors.

Abstract: An apparatus includes a global baseliner circuit coupled with sensing channels of a sensing device. The global baseliner circuit has a signal generator to generate a rectified sinusoidal signal and a square wave having a frequency matching that of an excitation sinusoidal signal, and is to use the square wave to modulate the excitation sinusoidal signal provided at an output of the global baseliner circuit. A channel baseliner circuit is coupled between the global baseliner circuit and a sensing channel and that includes a switched capacitor coupled between the output of the global baseliner circuit and the sensing channel; a sigma-delta modulator coupled with the signal generator and to generate, from the rectified sinusoidal signal, a density-modulated bit stream; and a pair of AND gates to use the density-modulated bit stream and non-overlapping clock signals to generate outputs including density-modulated clock signals sent to switches of the switched capacitor.

Abstract: Systems, methods, and devices detect defects in touch panels. Methods include scanning, using a designated integration window, a plurality of electrodes of a sensing device to obtain a plurality of measurements and determining a plurality of variance values for the plurality of electrodes based on the plurality of measurements, the plurality of variance values identifying variances in the plurality of measurements between adjacent sense locations of the sensing device. Methods also include determining if a defect is present in the sensing device based, at least in part, on a comparison of the plurality of difference values with the plurality of threshold values.

Abstract: Systems, methods, and devices improve the sensitivity of capacitive sensors. Devices may include an attenuator configured to receive an input from at least one sense electrode of a capacitive sensing device. The attenuator may be included in a sensing channel of a capacitive sensor. Devices may further include a signal generator coupled to an input of the attenuator. The signal generator may include one or more processors configured to generate a sinusoidal signal based, at least in part, on one or more noise characteristics of a scan sequence associated with one or more transmit electrodes of the capacitive sensing device, and provide the sinusoidal signal to the input of the attenuator.

Abstract: A capacitive sensor includes a switching capacitor circuit, a comparator, and a charge dissipation circuit. The switching capacitor circuit reciprocally couples a sensing capacitor in series with a modulation capacitor during a first switching phase and discharges the sensing capacitor during a second switching phase. The comparator is coupled to compare a voltage potential on the modulation capacitor to a reference and to generate a modulation signal in response. The charge dissipation circuit is coupled to the modulation capacitor to selectively discharge the modulation capacitor in response to the modulation signal.

Abstract: Technology directed to low-emissions touch controller in in-cell touch display systems is described. One in-cell touch controller includes a signal generator circuit that is configured to generate a sense signal according to a sensing function, the sense signal including a windowed sinusoidal waveform. The controller generates a transition signal to transition the in-cell touch display between a display function and the sensing function. The controller drives the sense signal and the transition signal on common voltage (VCOM) layer of electrodes during a touch scanning interval. During a display function interval an integrated display driver is configured to drive a first signal on the VCOM layer of electrodes during a display function interval.

Abstract: An elongated stylus is configured to be capacitively coupled with a sensor array providing a plurality of electrodes to indicate a position on the sensor array. The stylus includes a housing having an end in an elongated direction of the housing, a conductive tip disposed at least partially extended from the end of the housing, an electrode disposed around the conductive tip and configured to at least partially expose the conductive tip, and a signal transmit drive circuit configured to provide a signal. Control is performed to form an electrical connection between the electrode and a ground and an electrical connection between the electrode and the signal transmit drive circuit when the elongated stylus is activated for capacitive coupling with the sensor array.

Abstract: A circuit, system, and method for measuring or detecting pressure or force of a fingerprint on an array of electrodes is described. Pressure or force may be measured or detected using a processed image of the fingerprint, or by measurement of capacitance of deformed variable capacitors.

Abstract: A method for detecting a finger at a fingerprint sensor includes detecting a presence of an object at a fingerprint sensor and, in response to detecting the presence of the object, acquiring image data for the object based on signals from the fingerprint sensor. The method further includes, for each subset of one or more subsets of the image data, calculating a magnitude value for a spatial frequency of the subset, and identifying the object as a finger based on comparing the magnitude value to a threshold.

Abstract: An elongated stylus is configured to be capacitively coupled with a sensor array providing a plurality of electrodes to indicate a position on the sensor array. The stylus includes a housing having an end in an elongated direction of the housing, a conductive tip disposed at least partially extended from the end of the housing, an electrode disposed around the conductive tip and configured to at least partially expose the conductive tip, and a signal transmit drive circuit configured to provide a signal. Control is performed to form an electrical connection between the electrode and a ground and an electrical connection between the electrode and the signal transmit drive circuit when the elongated stylus is activated for capacitive coupling with the sensor array.

Abstract: Technology directed to low-emissions touch controller in in-cell touch display systems is described. One in-cell touch controller includes a signal generator circuit that is configured to generate a sense signal according to a sensing function, the sense signal including a windowed sinusoidal waveform. The controller generates a transition signal to transition the in-cell touch display between a display function and the sensing function. The controller drives the sense signal and the transition signal on common voltage (VCOM) layer of electrodes during a touch scanning interval. During a display function interval an integrated display driver is configured to drive a first signal on the VCOM layer of electrodes during a display function interval.

Abstract: Embodiments described herein provide capacitive sensor devices and methods for operating capacitive sensor devices. A first number of electrodes on the capacitive sensor array is activated. A signal is received from each of the first number of electrodes with a second number of receiver circuits on a controller associated with the capacitive sensor array. The first number is greater than the second number. It is determined if an object is proximate the capacitive sensor array based on the signals received from the first number of electrodes.

Abstract: Systems, methods, and devices improve the sensitivity of capacitive sensors. Devices may include an attenuator configured to receive an input from at least one sense electrode of a capacitive sensing device. The attenuator may be included in a sensing channel of a capacitive sensor. Devices may further include a signal generator coupled to an input of the attenuator. The signal generator may include one or more processors configured to generate a sinusoidal signal based, at least in part, on one or more noise characteristics of a scan sequence associated with one or more transmit electrodes of the capacitive sensing device, and provide the sinusoidal signal to the input of the attenuator.

Abstract: Technology directed to low-emissions touch controller in in-cell touch display systems is described. One in-cell touch controller includes a signal generator circuit that is configured to generate a sense signal according to a sensing function, the sense signal including a windowed sinusoidal waveform. The controller generates a transition signal to transition the in-cell touch display between a display function and the sensing function. The controller drives the sense signal and the transition signal on common voltage (VCOM) layer of electrodes during a touch scanning interval. During a display function interval an integrated display driver is configured to drive a first signal on the VCOM layer of electrodes during a display function interval.