Abstract: An electronic device includes one or more unit pixels and threshold voltage (Vth) sensing circuitry. The threshold voltage sensing circuitry senses Vth of the one or more unit pixels, by: sampling a charge of a capacitor of the one or more unit pixels, transitioning from the sampling, and reading out the threshold voltage based upon a change in the charge of the capacitor, such that an operation of the one or more unit pixels may be modified based upon the threshold voltage.

Abstract: An electronic device includes a display panel with pixels arranged in at least one row and at least one column. The electronic device also includes a sensing channel coupled to the at least one column. The sensing channel indirectly calculates a threshold voltage of the plurality of pixels based on an application of a first current level and a second current level to a data line of a first column of the at least one column of the pixels.

Abstract: An electronic device includes one or more unit pixels with a first node, a second node, and a third node. The device includes light-emitting-diode (LED) voltage (Vled) sensing circuitry, that senses Vled of the one or more unit pixels, by: sampling a charge of a capacitor of the one or more unit pixels, transitioning from the sampling, and reading out the Vled based upon a change in the charge of the capacitor, such that an operation of the unit pixel may be modified based upon the Vled.

Abstract: An electronic device may be provided with wireless circuitry and a display. A display driver integrated circuit in the display may have a spectrum analyzer circuit. An antenna may monitor for wireless signals. The display driver integrated circuit may use the spectrum analyzer circuit to analyze the wireless signals and determine whether there is a potential for visible display artifacts. In the presence of conditions that can lead to display artifacts, the display driver integrated circuit may adjust a gate driver control signal. Adjustments to the gate driver control signal may be made using adjustable signal dividers. The adjustments to the gate driver control signal eliminate the visible display artifacts.

Abstract: A display may receive image data to be displayed for a user of an electronic device. Display driver circuitry in the display may analyze the data to detect static data. The image data may contain static frames of data or static portions of a frame of data. In response to detection of static data, the display driver circuitry can take actions to avoid display damage due to burn-in effects. The display driver circuitry may reduce a peak luminance value associated with a peak luminance control algorithm, may reduce display brightness, may map image data to reduced brightness levels, or may take other actions to ensure that display pixels in the display are not damaged. Temperature information may be used in determining how to classify information as static data and in determining how significantly to reduce display pixel drive currents in response to the detection of static image data.

Abstract: A display may have an array of display pixels to display images. Digital display data may be received by a digital-to-analog converter. The digital-to-analog converter can convert the digital display data to analog display data for the display pixels. The magnitudes of the analog display data signals that the digital-to-analog converter provides to the display pixels can be controlled by a control signal such as a reference voltage received by the digital-to-analog converter. A brightness controller may have multiple peak luminance control profiles. A brightness setting may be processed by a look-up table to produce information identifying a selected one of the peak luminance control profiles. The brightness controller may use the selected peak luminance control profile and average frame luminance for the digital display data to produce the reference voltage that controls the digital-to-analog controller.

Abstract: A display may have an array of display pixels to display images. Digital display data may be received by a digital-to-analog converter. The digital-to-analog converter can convert the digital display data to analog display data for the display pixels. The magnitudes of the analog display data signals that the digital-to-analog converter provides to the display pixels can be controlled by a control signal such as a reference voltage received by the digital-to-analog converter. A brightness controller may have multiple peak luminance control profiles. A brightness setting may be processed by a look-up table to produce information identifying a selected one of the peak luminance control profiles. The brightness controller may use the selected peak luminance control profile and average frame luminance for the digital display data to produce the reference voltage that controls the digital-to-analog controller.

Abstract: A display may have a substrate layer to which a display driver integrated circuit and flexible printed circuit are bonded. The display driver integrated circuit may be provided with switches and control circuitry for controlling the operation of the switches during bond resistance measurements. Test equipment may apply currents to pads in the display driver integrated circuit through contacts in the flexible printed circuit while controlling the switching circuitry. Based on these measurements and the measurement of trace resistances in a dummy flexible printed circuit, the test equipment may determine bond resistances for bonds between the display driver integrated circuit and the display substrate and between the flexible printed circuit and the display substrate. Displays may have master and slave display driver integrated circuits that share coarse reference voltages produced by the master from raw power supply voltages.

Abstract: A display may have a substrate layer to which a display driver integrated circuit and flexible printed circuit are bonded. The display driver integrated circuit may be provided with switches and control circuitry for controlling the operation of the switches during bond resistance measurements. Test equipment may apply currents to pads in the display driver integrated circuit through contacts in the flexible printed circuit while controlling the switching circuitry. Based on these measurements and the measurement of trace resistances in a dummy flexible printed circuit, the test equipment may determine bond resistances for bonds between the display driver integrated circuit and the display substrate and between the flexible printed circuit and the display substrate. Displays may have master and slave display driver integrated circuits that share coarse reference voltages produced by the master from raw power supply voltages.

Abstract: Systems, methods, and devices for adjusting a white point of a liquid crystal display (LCD) using column inversion are provided. In one example, a method includes measuring white points of an electronic display that occur when the display employs different column inversion schemes. The display may be programmed to perform the column inversion scheme that produces a white point closest to a desired white point.

Abstract: Devices and methods for reducing or eliminating image artifacts are provided. By way of example, a method of preventing an occurrence of an image artifact on a display panel may include generating a first gate signal to be supplied to a first gate of a first transistor, generating a second gate signal to be supplied to a second gate of a second transistor, and adjusting a falling edge rate of the first gate signal or a rising edge rate of the second gate signal to reduce a voltage drop associated with row pixels of the display panel. Adjusting the falling edge rate of the first gate signal or the rising edge rate of the second gate signal include decreasing the falling edge rate of the first gate signal or the rising edge rate of the second gate signal during a period of time in which the first gate signal falls.

Abstract: An electronic device may be provided with a housing such as a metal housing in which a display is mounted. Control circuitry in the electronic device such as a system-on-chip integrated circuit may produce image data. A display driver integrated circuit may receive the image data from the system-on-chip integrated circuit and may display the image data on the display. In the absence of electrostatic discharge, the display driver integrated circuit may operate normally and may generate a heartbeat signal. When disrupted due to electrostatic discharge, the display driver circuitry may cease production of the heartbeat signal. The system-on-chip integrated circuit can implement a watchdog timer. If the watchdog timer times out because the heartbeat signal is not received within a timeout period, the system-on-chip integrated circuit may reset the display.

Abstract: An electronic device may be provided with wireless circuitry and a display. A display driver integrated circuit in the display may have a spectrum analyzer circuit. An antenna may monitor for wireless signals. The display driver integrated circuit may use the spectrum analyzer circuit to analyze the wireless signals and determine whether there is a potential for visible display artifacts. In the presence of conditions that can lead to display artifacts, the display driver integrated circuit may adjust a gate driver control signal. Adjustments to the gate driver control signal may be made using adjustable signal dividers. The adjustments to the gate driver control signal eliminate the visible display artifacts.

Abstract: An electronic device may include a display. The display may be formed by an array of light-emitting diodes mounted to the surface of a substrate. The substrate may be a silicon substrate. Circuitry may be located in spaces between the light-emitting diodes. Circuitry may also be located on the rear surface of the silicon substrate and may be coupled to the array of light-emitting diodes using through-silicon vias. The circuitry may include integrated circuits and other components that are attached to the substrate and may include transistors and other circuitry formed within the silicon substrate. Touch sensor electrodes, light sensors, and other components may be located in the spaces between the light-emitting diodes. The substrate may be formed from a transparent material that allows image light to reach a lens and image sensor mounted below the substrate.

Abstract: Systems, methods, and devices for reducing the loss of transmittance caused by column inversion. To provide one example, an electronic display may include a display panel with columns of pixels and driver circuitry to drive the pixels using column inversion. Adjacent columns that are driven at like polarity are spaced more closely than adjacent columns driven at opposite polarities.

Abstract: Devices and methods for reducing or eliminating image artifacts are provided. By way of example, a display panel includes a pixels including pixel electrodes configured to receive an image data signal, and common electrodes (VCOMs) configured to receive a common voltage signal. The display panel includes a source driver, which includes a first digital to analog converter (DAC) configured to generate a gamma voltage signal to provide a first adjustment to the image data signal, and a second DAC configured to generate an error correction voltage signal to provide a second adjustment to the image data signal. The second adjustment is configured to adjust the image data signal to compensate for an operational characteristic difference between row pixels and column pixels of the display panel. The source driver includes an output buffer to supply the image data signal to the pixel electrodes.

Abstract: Methods and devices employing mura prevention circuitry, are provided. In one example, a method may include supplying a first voltage pathway between a common electrode driver and a common electrode of an electronic display device and supplying a second voltage pathway between the common electrode driver and ground. Mura prevention circuitry may be supplied that activates the first voltage pathway when the electronic display device is turned on and an activation gate signal is provided from a gate corresponding to the common electrode driver. Further, the mura prevention circuitry may activate the second voltage pathway when the electronic display device is turned off or no activation gate signal is provided from the gate corresponding to the common electrode driver.

Abstract: A display may include an array of organic light-emitting diode display pixels having transistors characterized by threshold voltages subject to transistor variations. Compensation circuitry may be used to measure at transistor threshold voltage for a pixel. The threshold voltage may be sampled by controlling the pixel to sample the threshold voltage onto a capacitor at the pixel. The compensation circuitry may include sense circuitry that may be operated in combination with the pixel to transfer charge from the capacitor to the sense circuitry such that the threshold voltage is produced at an output of the sense circuitry. The compensation circuitry may generate compensation data based on the measured threshold voltage. During display operations, data circuitry may receive digital image data and process the digital image data along with the compensation data to generate analog data signals for the pixel.

Abstract: A system, method, and device for increasing uniformity between displays incorporating components from different manufacturers. Incorporating components from different manufactures in different displays may cause the different displays to appear differently even under similar conditions. By modifying the operating parameters used to drive the display according to performance characteristics for various conditions, displays incorporating components from different manufacturers may be configured to produce a substantially similar picture under similar conditions. The various conditions may include stimulus information, such as temperature or touch activity.

Abstract: Methods and devices employing circuitry for reducing power usage of a touch-sensitive display are provided. In one example, a method includes receiving power for a display of an electronic device. The method also includes powering a touch subsystem and a display subsystem of the display. The method includes, in a standard display mode, storing a frame of data in pixels of the display subsystem during a first period of time. The method also includes, in a low power display mode, storing a frame of data in pixels of the display subsystem during a second period of time. The second period of time is not equal to the first period of time. The method includes detecting a touch of the display via the touch subsystem between each synchronization signal of a plurality of synchronization signals received by the display.