Abstract: The present disclosure relates to systems and methods of accounting for the kickback voltage in an LCD display. For example, a method may include obtaining, via a processor, a difference between a nominal voltage of a common electrode of a display and a measured voltage of the common electrode. The processor may obtain image data associated with an image to be displayed on the display. The processor may adjust the image data of a pixel of the display based on the difference. The processor may output an image signal indicative of the adjusted image data to a pixel electrode of the pixel.

Abstract: A display may have an array of pixels. Due to the presence of a notch in the display, the display may have some rows that are shorter than other rows in the display, and accordingly different gate line loading. To account for the gate line loading variations, the display driver circuitry may have gate driver circuits that provide different gate line signals to different rows of pixels within the display. In other arrangement, luminance adjustment circuitry may receive image data and generate corresponding compensated image data to account for gate line loading variations between rows of pixels in the display. The image data may be compensated based on the location of the pixel, the gray level of the image data, the display brightness, and/or temperature.

Abstract: Circuits, methods, and apparatus that may estimate the power being consumed by an OLED display screen of an electronic device, may provide further information about that power usage, may modify or change functions performed by the electronic device based on that power usage, and may inform an application's developer about the amount of power being used by the electronic device while the electronic device is running the application. One example may estimate the power being used by an OLED display screen of an electronic device by determining the content of images being displayed during a duration. The estimated power may then be presented to a user. The estimated power may be used in decisions to modify or change parameters of the screen or other device components.

Abstract: A flat-panel display device and method to compensate for a voltage drop by supply voltage in the flat-panel display.

Abstract: Systems and methods are provided for improving displayed image quality of an electronic display that includes a display pixel. The electronic display displays a first image frame directly after a second image frame by applying an analog electrical signal to the display pixel. To facilitate display of the first image frame, circuitry receives image data corresponding to the image frame, in which the image data includes a grayscale value that indicates target luminance of the display pixel; determines expected refresh rate of the first image frame based at least in part on actual refresh rate of the second image frame; determines a pixel response correction offset based at least in part on the expected refresh rate of the first image frame; and determines processed image data by applying the pixel response correction offset to the grayscale value, in which the processed image data indicates magnitude of the analog electrical signal.

Abstract: A touch screen is disclosed. A plurality of common electrodes can be configured to operate as display circuitry during a display phase, and to operate as touch sensing circuitry during a touch sensing phase. The plurality of common electrodes can include a first common electrode associated with a first display pixel, and a second common electrode associated with a second display pixel. Circuitry can be configured to update the first display pixel at a first time while driving the first common electrode but not the second common electrode, and update the second display pixel at a second time, after the first time, while driving the second common electrode but not the first common electrode. In some examples, the circuitry can be configured to leave the second common electrode floating while driving the first common electrode, and leave the first common electrode floating while driving the second common electrode.

Abstract: Display-to-touch noise may be perceptible when a touch image generated during an active period of an electronic display of an electronic device is used to determine a touch indication on the display. The electronic device may include a display pixel layer including a plurality of display pixels that write display images to the display during a display active period and continue displaying the display image during a display blanking period. The electronic device may also include a touch sense layer including a plurality of touch sense pixels that facilitate generation of a first touch image during a first display active period and generation of a second touch image during a first display blanking period. The electronic device may further include a controller coupled to the display pixel layer and the touch sense layer that facilitates the reduction or elimination of display-to-touch interference.

Abstract: A display device may include a display having a plurality of pixels. The display device may also include a replica pixel circuit having a switching device configured to output a first current based on a received voltage, a light-emitting diode (LED) configured to illuminate to a first gray level based on the first current output by the switching device, and current mirror circuitry configured to generate a second current that mirrors the first current. In addition, the replica pixel circuit may include a current source configured to output a reference current based on a voltage value that corresponds to the received voltage, comparator circuitry configured to determine a difference between the second current and the reference current, and voltage adjustment circuitry configured to adjust a source voltage output provided to the plurality of pixels based on the difference.

Abstract: An electronic device may include a display for displaying image content to a user and dynamic image stabilization circuitry for dynamically compensating the image content if the device is moving unpredictably to help keep the image content aligned with the user's gaze. The electronic device may include sensors for detecting the displacement of the device. The dynamic image stabilization circuitry may include a usage scenario detection circuit and a content displacement compensation calculation circuit. The usage scenario detection circuit receives data from the sensors and infers a usage scenario based on the sensor data. The content displacement compensation calculation circuit uses the inferred usage scenario to compute a displacement amount by which to adjust image content. When motion stops, the image content may gradually drift back to the center of the display.

Abstract: An apparatus is disclosed. In some examples, the apparatus comprises a display panel comprising a plurality of display pixels. In some examples, the apparatus comprises a plurality of temperature sensors disposed at different portions the display panel, wherein the plurality of temperature sensors comprise ratioed pairs of thin film transistors and the ratioed pairs of thin film transistors are formed on the display panel. In some examples, the apparatus comprises control circuitry for changing illumination properties of the plurality of display pixels based on changes is temperature detected by a proximate temperature sensor of the plurality of temperature sensors. In some examples, the ratioed pairs of thin film transistors are operated in a sub-threshold mode.

Abstract: Methods and systems for compensating for VCOM variations include determining a voltage change in pixels between frames to be displayed on an electronic display. Based on the determined voltage change, VCOM variation is calculated based on coupling the VCOM to one or more data lines of the electronic display. VCOM compensation is determined and applied to offset for the VCOM variation. Using the VCOM offset, subsequent pixel content for the one or more pixels is written using the compensated VCOM.

Abstract: An electronic device such as a head-mounted display or other display system may have a pair of adjustable focal length lenses. Control circuitry in the head-mounted display may adjust the adjustable focal length lenses so that the adjustable focal length lenses exhibit a series of different focal lengths. A graphics processor may generate undistorted image frames. The adjustable focal length lenses may exhibit a different amount of lens distortion at each focal length. To compensate for these different amounts of lens distortion, a distortion compensation circuit may predistort the undistorted image frames by an appropriate amount for each focal length. The distortion compensation circuit may include mapping and interpolation circuitry and look-up tables that store mapping and interpolation data for each of the focal lengths.

Abstract: The disclosure relates to systems and methods for reducing VCOM settling periods. A number of pixels is sub-divided into a plurality of regions. The pixels are configured to transmit light. A common voltage (VCOM) driving circuit is configured to drive a common electrode of the pixels. Moreover, each of a number of VCOM driving circuits includes a variable resistor configured to be driven to a resistance level based at least in part on which region of the plurality of regions includes an active pixel within the region. Furthermore, a resistance level is set and based at least in part on where the active pixel is located.

Abstract: Aspects of the subject technology relate to pulsed backlight operation for a display backlight. Backlight pulse patterns are provided that include steady state pulse patterns to be applied during operation of a liquid crystal display unit of the display at a corresponding frame rate. The backlight pulse patterns can be arranged to prevent visible artifacts such as flicker or strobing, particularly at or near a transition between LCD frame rates.

Abstract: A display may have curved edges such as rounded corners. Pixels in the display may be controlled so that the active area of the display has the desired curved edge shape. In order to maximize the apparent smoothness of the curved edge, the display may include circuitry that dims some of the pixels based on their location relative to a spline for the curved edge. The display circuitry may include a multiplication circuit that receives image data as a first input and dimming factors from a gain table as a second input. The image data may include a brightness level for each pixel in the array of pixels. The multiplication circuit may multiply the brightness level for each pixel by its respective dimming factor. This modified image data may then be supplied to the imaging pixels using display driver circuitry.

Abstract: An electronic device may have a display such as an organic light-emitting diode display. Electronic devices may also include a number of sensors such as accelerometers and gaze detection sensors. A graphics processing unit (GPU) may render digital pixel values for pixels in the device display. Frames (F2) with long rendering times may cause latency. To reduce latency, an image frame may be displayed for an extended period of time (68) to wait for the subsequent frame (F2) to finish rendering. Once the subsequent image frame (F2) has finished rendering, the subsequent image frame may be displayed without delay. To increase the lifespan of the display, variable persistence may be used. Sensor data and other factors may be used to dynamically determine persistence for minimal motion blur and maximum display lifespan. Sensor data may also be used to determine refresh rates for different portions of the display.

Abstract: An electronic device may have a display and a gaze tracking system. The electronic device may display images on the display that have a higher resolution in a portion of the display that overlaps a gaze location than other portions of the display. Timing controller circuitry and column driver circuitry may include interpolation and filter circuitry. The interpolation and filter circuitry may be used to perform nearest neighbor interpolation and two-dimensional spatial filtering on low resolution image data. Display driver circuitry may be configured to load higher resolution data into selected portions of a display. The display driver circuitry may include low and high resolution image data buffers and configurable row driver circuitry. Block enable transistors may be included in a display to allow selected blocks of pixels to be loaded with high resolution image data.

Abstract: An electronic device that includes processing circuitry configured to generate a frame of image data that has a frame duration is provided. The electronic device includes a display that has a plurality of pixels. Each of the plurality of pixels displays image data from the frame of image data for a pixel emission period that is less than the frame duration. A first pixel of a column of pixels of the plurality of pixels begins displaying the image data from the frame of image data at a first time for a first duration. A second pixel of the column of pixels that is adjacent to the first pixel begins displaying the image data from the frame of image data at a second time for a second duration. The first and second durations are equal to the pixel emission period. The second time begins after the first duration of time.

Abstract: This application relates to performing certain dithering processes to eliminate display artifacts such as flicker, which can be caused by charge accumulation at the display. The dither process can be performed by a display controller that uses a group lookup method for identifying groups of dithering patterns that can be combined to expand a number of color values available to the display. The dither process can also be performed as a temporal process that incorporates groups of dithering patterns into frames and shifts a spatial arrangement of the groups of dithering patterns over a sequence of frames. Additionally, the dither process can incorporate counters that count the number of times a particular spatial arrangement of dithering patterns has been used in a sequence of frames in order that each spatial arrangement of dithering patterns will share an average count with other spatial arrangements over a sequence of frames.

Abstract: An electronic device such as a head-mounted device may have displays. The display may have regions of lower (L) and higher (M, H) resolution to reduce data bandwidth and power consumption for the display while preserving satisfactory image quality. Data lines may be shared by lower and higher resolution portions of a display or different portions of a display with different resolutions may be supplied with different numbers of data lines. Data line length may be varied in transition regions between lower resolution and higher resolution portions of a display to reduce visible discontinuities between the lower and higher resolution portions. The lower and higher resolution portions of the display may be dynamically adjusted using dynamically adjustable gate driver circuitry and dynamically adjustable data line driver circuitry.