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: 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: 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: A touch screen configured for optical touch sensing and user identification using organic light emitting diodes (OLEDs) is disclosed. In some examples, one or more OLEDs can be used to display one or more images on the device, can be configured to emit light for optical touch sensing, and/or can be configured to detect a reflection of the emitted light. The touch screen can include a spatial filter configured to focus light emitted from the OLEDs and/or reflected light detected by the OLEDs for improved optical touch sensing. Using optical touch sensors, the touch screen can be capable of discerning between water and an object (e.g., finger) and/or noise (e.g., ambient light) and an object. The touch screen can also be capable of identifying (e.g., authenticating) a user using the active area of the device.

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: A multi-chip touch architecture for scalability can include one or more touch controller application specific integrated circuits (ASICs), and one or more switching circuits coupled between the one or more touch controller ASICs and the touch sensor panel. The number of touch controller ASICs and switching circuits can be scaled based on the size of the touch sensor panel. The touch controller ASICs can include an interface for data transfer between the touch controller ASICs to allow for parallel processing of an image of touch by more than one touch controller ASIC. The touch controller ASIC can also include a memory directly accessible by more than one processing circuit (e.g., hardware accelerators), and circuitry to dynamically adjust the coupling between portions (e.g., banks) of memory and inputs of the one or more processing circuits to minimize data transfer and improve processing speeds.

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: 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 concurrent touch and negative pixel scan performed at a touch panel is disclosed. The concurrent scan can include sensing an object proximate to the touch panel and sensing a negative pixel effect, based the object's grounding condition, at the touch panel, at the same time. As a result, sense signals indicative of the proximity of the object and coupling signals indicative of the negative pixel effect's magnitude can be captured concurrently. Because the negative pixel effect can cause errors or distortions in the sense signals, the coupling signals can be used to compensate the sense signals for the negative pixel effect.

Abstract: Measuring an effect of body capacitance in a touch sensitive device is disclosed. This effect can be caused by poor grounding of a user or other objects touching the device or of the device itself. The device can operate in a stray capacitance mode to measure a body capacitance effect and in a normal mode to detect a touch on the device. During the stray capacitance mode, the device can obtain a body capacitance measurement from the device. During the normal mode, the device can obtain a touch measurement from the device. The device can calculate a body capacitance factor based on a ratio between the body capacitance measurement and the touch measurement and use the body capacitance factor to compensate for erroneous or distorted touch output values from the device. Various components of the device can be switchably configured according to the particular mode.

Abstract: A multi-modal touch controller configured to operate in different modes. In some examples, the multi-modal touch controller can be operated in a first mode corresponding to a guarded self-capacitance scan. In some examples, the multi-modal touch controller can be operated in a second mode corresponding to offset-compensated mutual capacitance scan. In some examples, the multi-modal controller can be operated in a third mode corresponding to a mutual and self-capacitance scan. The multi-modal touch controller can advantageously allow one touch sensing chipset to be used across different types of guarded touch sensor panels and across different modes of operation.

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: 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.

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: 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. The touch controller can be incorporated into a touch sensitive device.

Abstract: Disclosed herein are liquid-crystal display (LCD) touch screens that integrate the touch sensing elements with the display circuitry. The integration may take a variety of forms. Touch sensing elements can be completely implemented within the LCD stackup but outside the not between the color filter plate and the array plate. Alternatively, some touch sensing elements can be between the color filter and array plates with other touch sensing elements not between the plates. In another alternative, all touch sensing elements can be between the color filter and array plates. The latter alternative can include both conventional and in-plane-switching (IPS) LCDs. In some forms, one or more display structures can also have a touch sensing function. Techniques for manufacturing and operating such displays, as well as various devices embodying such displays are also disclosed.

Abstract: A method for pre-charging a display panel may include simultaneously charging the display panel that displays image data and receives one or more touch inputs via a first voltage source and a capacitor that provides a first voltage to the display panel via a second voltage source. The first voltage is associated with receiving the one or more touch inputs, and the display panel and the capacitor are simultaneously charged for a first amount of time. The method may then include charging the display panel via the capacitor after the first amount of time for a second amount of time and charging the display panel via the second voltage source after the second amount of time for a third amount of time.

Abstract: Self capacitance touch circuits to cancel the effects of parasitic capacitance in a touch sensitive device are disclosed. One circuit can generate a parasitic capacitance cancelation signal that can be injected into touch sensing circuitry to cancel the parasitic capacitance. Another circuit can adjust the phase and magnitude of the parasitic capacitance cancelation signal based on characteristics of channels in the touch sensing circuitry so as to fine tune the parasitic capacitance cancelations. Another circuit can drive a guard plate and touch panel electrodes so as to cancel the parasitic capacitances between the panel and the plate and between the electrodes.

Abstract: An integrated touch sensing and force sensing device is included in an electronic device. The integrated touch sensing and force sensing device includes a force-sensitive layer operably attached to an input surface, a first electrode layer attached to a first surface of the force-sensitive layer, and a second electrode layer attached to a second surface of the force-sensitive layer. An analog front end processing channel is operable to process a touch signal that is based on a change in an electrical property between the first and second electrode layers and operable to process a force signal that is based on an electrical property generated by the force-sensitive layer based on a force applied to the input surface.

Abstract: A channel scan architecture for detecting touch events on a touch sensor panel is disclosed. The channel scan architecture can combine drive logic, sense channels and channel scan logic on a single monolithic chip. The channel scan logic can be configured to implement a sequence of scanning processes in a panel subsystem without intervention from a panel processor. The channel scan architecture can provide scan sequence control to enable the panel processor to control the sequence in which individual scans are implemented in the panel subsystem. Type of scans that can be implemented in the panel subsystem can include a spectral analysis scan, touch scan, phantom touch scan, ambient light level scan, proximity scan and temperature scan.