Abstract: A multipoint touch surface controller is disclosed herein. The controller includes an integrated circuit including output circuitry for driving a capacitive multi-touch sensor and input circuitry for reading the sensor. Also disclosed herein are various noise rejection and dynamic range enhancement techniques that permit the controller to be used with various sensors in various conditions without reconfiguring hardware.

Abstract: Techniques for mitigating noise in a touch signal are disclosed. To reduce or eliminate noise in a touch signal, the touch activity can be filtered out of a touch signal, thus isolating the noise. In some examples, the noise is then provided to the non-inverting input port of a differential amplifier while the unfiltered touch signal is provided to the inverting input port of the differential amplifier. The noise, which is now common on both inputs, is automatically eliminated or reduced by the differential amplifier.

Abstract: An integrated touchscreen can include light emitting diodes or organic light emitting diodes (LEDs/OLEDs), display chiplets and touch chiplets disposed in a visible area of the integrated touch screen. For example, the LEDs/OLEDs, display chiplets and touch chiplets can be placed on a substrate by a micro-transfer tool. The integrated touchscreen can also include electrodes disposed in the visible area of the integrated touch screen. The electrodes can be capable of providing display functionality via the one or more display chiplets during display operation (e.g., operating as cathode terminals of the LEDs during the display operation) and capable of providing touch functionality via the touch chiplets during touch operation (e.g., touch node electrodes can be formed from groups of the electrodes and sensed). In some examples, the touch node electrodes can be formed and coupled to touch chiplets via the display chiplets.

Abstract: An electronic device can include an integrated touch and display chip that can operate in multiple power domains. For example, the integrated touch and display chip can operate in a guarded power domain during the touch operation and can operate in a system power domain during non-guarded display operations. In some examples, two power domains can include a guarded power domain and a system power domain, whose grounds can be differentiated by a guard buffer signal. In some examples, the guard buffer can be disposed between the integrated touch and display chip and a battery of the device. In some examples, the guard buffer can be disposed between the battery of the device and the chassis of the device.

Abstract: The disclosure relates to a touch and/or proximity detection system having some components operating in the guard domain and other components operating in the earth or chassis ground domain. A guard chip in the earth or chassis ground domain can include a voltage driver configured to produce a guard signal, for example. In some examples, the guard signal can be coupled to one or more shielding electrodes of a touch screen and to the ground pin of one or more touch sensing chips of the touch and/or proximity detection system. In this way, for example, the touch sensing chips, which can include sense amplifiers coupled to one or more sensing electrodes of the touch screen, can operate in the guard domain. In some examples, the guard chip can further include differential amplifiers and/or ADCs, allowing these components to operate in the earth or chassis ground domain.

Abstract: A display may have an array of light-emitting pixels that display an image in an active area of the display. These light-emitting pixels may be visible light pixels such as red, green, and blue thin-film organic light-emitting diode pixels. The display may also have a border region that runs along a peripheral edge of the active area. The border region may be free of pixels that display image light, whereas the active area may be free of light detectors. A non-optical touch sensor such as a capacitive touch sensor may overlap the active area to gather touch input from the active area. The non-optical touch sensor may not overlap any portion of the border region. In the border region, an optical sensor formed from infrared light-emitting pixels and infrared light-sensing pixels or other optical sensing circuitry may serve as an optical touch sensor.

Abstract: Some touch screens can be formed by at least partially integrating touch sensing circuitry into a display pixel stackup. In some examples, noise can be introduced into touch sensor panel measurements, for example, from display data lines of a display device proximate to the touch sensor panel. In some examples, rows or columns of touch electrodes can be split and a first portion of the touch sensor panel can be stimulated to measure capacitance and noise and a second portion of the touch sensor panel can be unstimulated and measure noise. In some examples, both the first and the second portions of the touch sensor panel can be stimulated using orthogonal stimulation codes. In some examples, measurements from the first and/or second portions of the touch sensor panel can be subtracted from measurements from the other portion of the touch sensor panel to eliminate or reduce common mode noise.

Abstract: A multipoint touch surface controller is disclosed herein. The controller includes an integrated circuit including output circuitry for driving a capacitive multi-touch sensor and input circuitry for reading the sensor. Also disclosed herein are various noise rejection and dynamic range enhancement techniques that permit the controller to be used with various sensors in various conditions without reconfiguring hardware.

Abstract: A switching circuit is disclosed. The switching circuit can comprise a plurality of pixel mux blocks, each of the pixel mux blocks configured to be coupled to a respective touch node electrode on a touch sensor panel, and each of the pixel mux blocks including logic circuitry. The switching circuit can also comprise a plurality of signal lines configured to be coupled to sense circuitry, at least one of the signal lines configured to transmit a touch signal from one of the respective touch node electrodes to the sense circuitry. The logic circuitry in each pixel mux block of the plurality of pixel mux blocks can be configured to control the respective pixel mux block so as to selectively couple the respective pixel mux block to any one of the plurality of signal lines.

Abstract: A touch sensing system is disclosed. The touch sensing system includes a guard signal generation chip operating in a first power domain referenced to a first voltage, the guard signal generation chip configured to generate a guard signal. A touch sensing chip operates in a second power domain, different from the first power domain, referenced to the guard signal, the touch sensing chip configured to sense touch at one or more touch electrodes included in a touch sensor panel operating in the second power domain referenced to the guard signal, and the touch sensing chip a different chip than the guard signal generation chip. A voltage regulator is configured to selectively regulate a voltage of the guard signal at the touch sensing chip.

Abstract: Some touch screens can be formed by at least partially integrating touch sensing circuitry into a display pixel stackup. In some examples, noise can be introduced into touch sensor panel measurements, for example, from display data lines of a display device proximate to the touch sensor panel. In some examples, rows or columns of touch electrodes can be split and a first portion of the touch sensor panel can be stimulated to measure capacitance and noise and a second portion of the touch sensor panel can be unstimulated and measure noise. In some examples, both the first and the second portions of the touch sensor panel can be stimulated using orthogonal stimulation codes. In some examples, measurements from the first and/or second portions of the touch sensor panel can be subtracted from measurements from the other portion of the touch sensor panel to eliminate or reduce common mode noise.

Abstract: Power management for a touch controller is disclosed. The touch controller can include a transmit section for transmitting stimulation signals to an associated touch sensor panel to drive the panel, where the touch controller can selectively adjust the transmit section to reduce power during the transmission. The touch controller can also include a receive section for receiving touch signals resulting from the driving of the panel, where the touch controller can selectively adjust the receive section to reduce power during the receipt of the touch signals. The touch controller can also include a demodulation section for demodulating the received touch signals to obtain touch event results, where the touch controller can selectively adjust the demodulation section to reduce power during the demodulation of the touch signals. The touch controller can also selectively reduce power below present low levels during idle periods.

Abstract: A device that can autonomously scan a sensor panel is disclosed. Autonomous scanning can be performed by implementing channel scan logic. In one embodiment, channel scan logic carries out many of the functions that a processor would normally undertake, including generating timing sequences and obtaining result data; comparing scan result data against a threshold value (e.g., in an auto-scan mode); generating row count; selecting one or more scanning frequency bands; power management control; and performing an auto-scan routine in a low power mode.

Abstract: A system and method for autonomously scanning a sensor panel device is disclosed. A sensor panel processor can be disabled after a first predetermined amount of time has elapsed without the sensor panel device sensing any events. One or more system clocks can also be disabled to conserve power. While the processor and one or more system clocks are disabled, the sensor panel device can periodically autonomously scan the sensor panel for touch activity. If one or more results from the autonomous scans exceed a threshold, the sensor panel device re-enables the processor and one or more clocks to actively scan the sensor panel. If the threshold is not exceeded, the sensor panel device continues to periodically autonomously scan the sensor panel without intervention from the processor. The sensor panel device can periodically perform calibration functions to account for any drift that may be present in the system.

Abstract: A switching circuit is disclosed. The switching circuit can comprise a plurality of pixel mux blocks, each of the pixel mux blocks configured to be coupled to a respective touch node electrode on a touch sensor panel, and each of the pixel mux blocks including logic circuitry. The switching circuit can also comprise a plurality of signal lines configured to be coupled to sense circuitry, at least one of the signal lines configured to transmit a touch signal from one of the respective touch node electrodes to the sense circuitry. The logic circuitry in each pixel mux block of the plurality of pixel mux blocks can be configured to control the respective pixel mux block so as to selectively couple the respective pixel mux block to any one of the plurality of signal lines.

Abstract: Power management for a touch controller is disclosed. The touch controller can include a transmit section for transmitting stimulation signals to an associated touch sensor panel to drive the panel, where the touch controller can selectively adjust the transmit section to reduce power during the transmission. The touch controller can also include a receive section for receiving touch signals resulting from the driving of the panel, where the touch controller can selectively adjust the receive section to reduce power during the receipt of the touch signals. The touch controller can also include a demodulation section for demodulating the received touch signals to obtain touch event results, where the touch controller can selectively adjust the demodulation section to reduce power during the demodulation of the touch signals. The touch controller can also selectively reduce power below present low levels during idle periods.

Abstract: A system and method for autonomously scanning a sensor panel device is disclosed. A sensor panel processor can be disabled after a first predetermined amount of time has elapsed without the sensor panel device sensing any events. One or more system clocks can also be disabled to conserve power. While the processor and one or more system clocks are disabled, the sensor panel device can periodically autonomously scan the sensor panel for touch activity. If one or more results from the autonomous scans exceed a threshold, the sensor panel device re-enables the processor and one or more clocks to actively scan the sensor panel. If the threshold is not exceeded, the sensor panel device continues to periodically autonomously scan the sensor panel without intervention from the processor. The sensor panel device can periodically perform calibration functions to account for any drift that may be present in the system.

Abstract: A method of temperature compensation in an optical-fingerprint detection system includes acquiring a first reading associated with one or more pixels of an array. The first reading is a baseline reading. The method further includes acquiring a second reading associated with the one or more pixels of the array. The second reading includes the baseline plus a signal. Producing a temperature compensated signal reading by subtracting the first reading from the second reading. The array is an optical-fingerprint array, and each pixel of the array is coupled to a readout circuit via a pixel switch. The method includes row-based and frame-based schemes and a blind pixel scheme. Readout circuit improvements including multiplexed analog front-end (AFE), charge magnifier with column charge offset compensation and a low-noise gate driver circuit are provided.

Abstract: A device that can autonomously scan a sensor panel is disclosed. Autonomous scanning can be performed by implementing channel scan logic. In one embodiment, channel scan logic carries out many of the functions that a processor would normally undertake, including generating timing sequences and obtaining result data; comparing scan result data against a threshold value (e.g., in an auto-scan mode); generating row count; selecting one or more scanning frequency bands; power management control; and performing an auto-scan routine in a low power mode.

Abstract: Power consumption of touch sensing operations for touch sensitive devices can be reduced by implementing a coarse scan (e.g., banked common mode scan) to coarsely detect the presence or absence of an object touching or proximate to a touch sensor panel and the results of the coarse scan can be used to dynamically adjust the operation of the touch sensitive device to perform or not perform a fine scan (e.g., targeted active mode scan). In some examples, the results of the coarse scan can be used to program a touch controller for the next touch sensing frame to idle when no touch event is detected or to perform a fine scan when one or more touch events are detected. In some examples, the results of the coarse scan can be used to abort a scheduled fine scan during the current touch sensing frame when no touch event is detected.