Abstract: An electronic device may be provided with a display. A content generator may generate frames of image data to be displayed on the display. The display may have an array of pixels that emit light to display images. The pixels may contain light-emitting devices such as organic light-emitting diodes, quantum dot light-emitting diodes, and light-emitting diodes formed from discrete semiconductor dies. As a result of aging, the light producing capabilities of the light-emitting devices may degrade over time. The electronic device may have a temperature sensor that gathers temperature measurements. A pixel luminance degradation compensator may apply compensation factors to uncorrected pixel luminance values associated with the frames of image data to produce corresponding corrected pixel luminance values for the display. The compensation factors may be based on aging history information such as pixel luminance history and temperature measurements.

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. Digital display data may be received by a digital-to-analog converter that converts the digital display data to analog display data. The magnitudes of the analog display data signals can be controlled by a regulated voltage received by the digital-to-analog converter. A brightness controller may have multiple peak luminance control (PLC) profiles. In accordance with an embodiment, a brightness setting may be processed by a lookup table to identify a pair of PLC profiles that is interpolated in order to obtain the desired regulated voltage. In accordance with another embodiment, a single PLC profile may be used that is a function of a combined parameter that takes into account both average frame luminance and the brightness setting. In accordance with yet another embodiment, a lookup table that specifies brightness setting offset values may be used to directly modulate the brightness setting.

Abstract: An electronic device that includes a display is provided. The display may have a brightness that is controlled using a series of cascaded digital-to-analog converter circuits. The display may be calibrated at a series of predetermined display brightness settings. For display brightness settings that fall between two consecutive display brightness settings in the series of predetermined display brightness settings, voltage interpolation operations may be performed to obtain the corresponding display brightness settings. Performing voltage interpolations instead of digital brightness setting interpolation helps minimize luminance jumps and unexpected color shifts when adjusting the brightness of the display.

Abstract: An organic light-emitting diode display may have an array of pixels. Each pixel may have multiple subpixels of different colors. To avoid undesired color shifts when operating the display, the display may be configured so that subpixels of different colors are not coupled to each other through parasitic capacitances. The subpixels may include red, green, and blue subpixels or subpixels of other colors. Each subpixel may include an organic light-emitting diode having an anode and a cathode. The anode of each organic light-emitting diode may be coupled to a respective storage capacitor. Capacitive coupling between subpixels can be minimized by configuring the subpixel structures of each pixel so that the storage capacitors of the subpixels do not overlap the anodes of other subpixels in the pixel. Anode and capacitor overlap with subpixel data lines may also be reduced or eliminated.

Abstract: An electronic device includes a transparent surface, a light emitting device that emits light through the transparent surface, and a light sensor for receiving ambient light and providing an ambient light value. A retarder and a linear polarizer are placed between the transparent surface and the light emitting device. The retarder and linear polarizer may attenuate internal reflections from the transparent surface. The light sensor may have two channels and a second linear polarizer may attenuate the ambient light directed toward a second channel. A second retarder may be used with the second linear polarizer to attenuate the ambient light directed toward the second channel. A light detection circuit may use the difference between the two channels of the light sensor to provide the ambient light value.

Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for a display with inactive dummy pixels. A display apparatus may include subpixels having a first electrode layer and a second electrode layer. The first electrode layer of an edge subpixel may include an opening, which may be made large enough to prevent the edge subpixel from actuating. The size of the openings also may be selected to attain a desired overall reflectivity for an array of edge subpixels. For example, the size of the openings may be selected to make the reflectivity of an edge pixel array similar to the reflectivity of a routing area.

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: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for reducing artifacts in an image generated by a display device. In one aspect, data is written to a display and a position of display elements is maintained based on the application of a bias voltage pattern. The bias voltage pattern includes alternating polarities along one dimension in a pattern having a first frequency spectrum, and alternating polarities along a second dimension in a pattern having a second frequency spectrum that is different than the first frequency spectrum. At least one of the first and second frequency spectrums may include a plurality of frequency components.

Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for calibrating display arrays. In one aspect, a method of calibrating a display array includes determining a particular drive response characteristic and updating a particular drive scheme voltage between updates of image data on the display array.

Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for displaying high resolution images using an adaptive temporal dithering scheme on display devices having two or more color planes. The adaptive temporal dithering scheme includes identifying the dither visibility of an image to be displayed by the color planes and adaptively applying temporal dithering to the color plane having the highest dither visibility. In one aspect, temporal dithering can be adaptively applied between two different color planes on a frame-by-frame basis based at least partly on the dither visibility of the image content.

Abstract: The present disclosure provides methods, systems, and apparatus for directing incident light toward central regions of interferometric modulator displays. In one aspect, a display includes an array of microlenses embedded in a substrate adjacent a first surface of the substrate. An array of light modulators can be disposed over the first surface of the substrate. A light modulator can be disposed over a corresponding microlens. The microlenses can converge or concentrate incident light onto central regions of the corresponding light modulators. The microlenses may include single-element lenses, compound lenses, and/or graded-index lenses. Various methods of manufacturing such displays are also disclosed.

Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for improving the visual appearance of displayed images at high frame rates by skipping writing lines of display data. In one aspect, clusters of changed image regions are detected, and lines are preferentially written when such clusters are detected.

Abstract: This disclosure provides methods and apparatus for calibrating display arrays. In one aspect, a method of calibrating a display array includes determining a particular drive response characteristic and updating a particular drive scheme voltage between updates of image data on the display array. The drive response characteristic may be determined by applying a ramped voltage to a line of the array and detecting a current pulse due to a capacitance change on the line. The drive response characteristic can be determined based on data representing a width of a current pulse in the waveform or a weighted or unweighted area of a current pulse in the waveform.

Abstract: Techniques are disclosed for updating an array of display elements of an electronic display. The electronic display, which may be an interferometric modulator (IMOD) display, includes an array of display elements that is updated, at a frame update rate, on a frame by frame basis. Each frame includes data to be written to a plurality of pixel rows, each pixel row including at least a respective first display element line (DEL) of a first color and a respective second DEL of a second color. A processor compares display data for each pixel row in a first frame with display data for a corresponding pixel row in a comparison frame, and updates only selected DEL's based on the comparison. A polarity of a bias voltage of a subset of DEL's in the display, is periodically inverted, the subset of DEL's being substantially fewer than all of the DEL's.

Abstract: This disclosure provides systems, methods and apparatus for mitigating or reducing stiction in electromechanical systems devices. The systems and methods described herein include a piezo-electric layer disposed over at least a portion of the deformable region of the electromechanical systems devices. To reduce or mitigate stiction, a restorative mechanical force is generated by reverse piezo-electric effect to return the deformable region of the electromechanical systems devices to the un-deformed state.

Abstract: For a personal electronic device (PED) having a display, the display including a cover glass having a front surface and a back surface, the PED includes a driver circuit configured to send at least one signal to the display and an ambient light sensor (ALS). Each of the driver circuit and the ALS is disposed behind the back surface of the cover glass. The ALS and the driver circuit may reside on a single substrate, which is disposed adjacent to the back surface of the cover glass. The ALS may output signals to the driver circuit that are indicative of ambient light level and one or both of ambient light spectrum and ambient light direction. The driver circuit may be configured to automatically adjust, in response to the signals, one or both of a display color bias and a display luminescence.

Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for reducing artifacts in an image generated by a display device. In one aspect, data is written to a display and a position of display elements is maintained based on the application of a bias voltage pattern. The bias voltage pattern includes alternating polarities along one dimension in a pattern having a first frequency spectrum, and alternating polarities along a second dimension in a pattern having a second frequency spectrum that is different than the first frequency spectrum. At least one of the first and second frequency spectrums may include a plurality of frequency components.

Abstract: This disclosure provides methods and apparatus, including computer programs encoded on computer storage media, for reducing visual aberrations on an electronic display. One aspect is a method of writing an input image data value to a display element in a electronic display. The method includes receiving an input image data value, and quantizing the image data value based on a threshold. The threshold may be modulated based on a voltage drive signal provided to the display element in the electronic display. The method may also write the quantized image data value to the display element.

Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for determining a line time for writing data to display elements on one or more common lines of an array of display elements. In one aspect, the line time is determined for writing data to a line of display elements based on the received image data to be written to the line of display elements.