Abstract: An array of pixels in a display may be illuminated by a backlight having an array of light-emitting diodes in an array of respective cells. A reflector is used to reflect light from the light-emitting diodes through the array of pixels. Within the cells, the reflector has cross-sectional profiles that help distribute light emitted from the light-emitting diodes toward edges of the cells. A light diffuser layer for the backlight may have a partially reflective layer such as a thin-film interference filter with an angularly dependent transmission. Within each cell, the reflector may have cross-sectional profiles with portions that are parabolic or elliptical.

Abstract: An electronic device may have a display with a backlight. The backlight provides backlight illumination for an array of pixels that is displaying images. The backlight may include an array of cells. Each cell may contain a light source with one or more light-emitting diodes and a cavity reflector that reflects light from the light source outwardly through a diffuser for use in forming the backlight illumination. The light sources may be mounted to a printed circuit. Support posts on the printed circuit may be used to maintain the diffuser at a fixed distance from the printed circuit. The support posts may have opposing first and second ends. The first ends may be attached to the diffuser with fixed connections such as adhesive connections. The second ends may be attached to the printed circuit using floating connections.

Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.

Abstract: A display calibration system may include a first electronic device that includes an ambient light sensor and a display to be calibrated in a second electronic device. The first electronic device may generate test patterns to be displayed on the display. The ambient light sensor may receive light emitted from the display based on the test patterns to generate display color space data. The first electronic device may generate calibration data for the display based on the display color space data and a target reference color space. The second electronic device may store the calibration data and use the calibration data to generate more accurate images. Because the first electronic device may include other functionalities other display calibration, specialized display calibration equipment may be omitted. Additionally, a third electronic device that acts as an intermediary between the first and second electronic devices.

Abstract: Textured cover assemblies for electronic devices are disclosed. The textured cover assemblies may be placed over a display and may provide anti-glare and anti-reflection properties to the electronic device.

Abstract: An electronic device includes a display having an emulation component and a separate calibration component. The emulation component may provide a user of the device with a list of available emulation presets at least some of which is common across a large batch of displays. The calibration component may include at least one factory calibration setting that may be shared among one or more of the emulation presets. The user may optionally add to the list of emulation presets by filling up empty emulation slots in the emulation component. The user may also be given the option to recalibrate the display or to add custom calibration datasets using calibration targets different than factory targets. The custom calibration datasets may be optimized for one or more of the emulation presets. Thus, when the user selects a particular emulation preset, the display may automatically select the desired calibration dataset for optimal performance.

Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.

Abstract: An electronic device may have a display mounted in a housing. The housing may have a stand that supports the housing on a support surface or may have other shapes. The display may have pixels that display an image. The display may also have a two-dimensional array of light-emitting devices such as light-emitting diodes that supply backlight illumination for the pixels. An array of temperature sensors may be overlapped by the pixels. Control circuitry may maintain historical backlight aging information during operation of the display. The aging information may include information on output brightness levels of the light-emitting diodes and light-emitting diode operating temperatures.

Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.

Abstract: An array of pixels in a display may be illuminated by a backlight having an array of light-emitting diodes in an array of respective cells. A reflector is used to reflect light from the light-emitting diodes through the array of pixels. Within the cells, the reflector has cross-sectional profiles that help distribute light emitted from the light-emitting diodes toward edges of the cells. A light diffuser layer for the backlight may have a partially reflective layer such as a thin-film interference filter with an angularly dependent transmission. Within each cell, the reflector may have cross-sectional profiles with portions that are parabolic or elliptical.

Abstract: A display may store extended display identification data for communicating the capabilities of the display to a source device such as a graphics processing unit. The extended display identification data may include a red primary color value, a green primary color value, and a blue primary color value. The primary color values in the extended display identification data may be determined during manufacturing. For example, a light sensor may measure the native primary colors of the display, and calibration computing equipment may determine if the native primary colors of the display are within a target color gamut. If the native primary colors of the display are outside of the target color gamut by an amount larger than a threshold, the primary color values in the extended display identification data may be adjusted to account for the color variation.

Abstract: An array of pixels in a display may be illuminated by a backlight having an array of light-emitting diodes in an array of respective light-emitting diode cells. A cavity reflector in each cell may help distribute blue light emitted from the light-emitting diode of that cell toward edges of the cell. Optical films in the backlight may include a photoluminescent layer such as a phosphor layer that converts blue light from the light-emitting diode array into white light and may include a dichroic filter for reflecting white light away from the diode array towards the pixel array. A light diffuser layer for the backlight may have printed white ink pads, recesses filled with a high index of refraction material, protrusions for light scattering, light-scattering particles, thin-film interference filters, partially reflective mirrors, and other structures for diffusing the light from the light-emitting diodes.

Abstract: A display such as a liquid crystal display may have an array of pixels that is illuminated using backlight illumination from a backlight. The backlight may have a light guide plate that distributes light from light-emitting diodes across the display. The light-emitting diodes may be overlapped by the light guide plate and may emit light into portions of the light guide plate that have ramped profiles. Light-emitting diodes for the backlight may have multiple light-emitting diode dies mounted on common package substrates. Reflective walls may be formed between the light-emitting diode dies on a substrate. Phosphor may cover the dies. The light-emitting diodes may contain four light-emitting diode dies that emit light in four different directions. Two or more of the dies may emit light of different colors. Light may be emitted into the corners of rectangular light distribution regions of a light guide plate.

Abstract: A display has an array of display pixels formed from display layers such as one or more polarizer layers, a substrate on which an array of display pixel elements such as color filter elements and downconverter elements are formed, a liquid crystal layer, and a thin-film transistor layer that includes display pixel electrodes and display pixel thin-film transistors for driving control signals onto the display pixel electrodes to modulate light passing through the display pixels. A light source such as one or more laser diodes or light-emitting diodes may be used to generate light for the display. The light may be launched into the edge of a polymer layer or other light guide plate structure. A light guide plate may include phase-matched structures such as holographically recorded gratings or photonic lattices that direct the light upwards through the array of display pixels.

Abstract: An electronic device may be provided with a display such as a liquid crystal display. The display may have a layer of liquid crystal material interposed between upper and lower polarizers. A first substrate such as a thin-film transistor layer may be interposed between the liquid crystal layer and the lower polarizer. A second substrate such as a color filter glass layer may be interposed between the upper polarizer and the liquid crystal layer. The color filter glass layer may have opposing upper and lower surfaces. The lower surface of the color filter glass layer may have an array of color filter elements. To prevent damage to display, an electrostatic shielding layer may be formed on the upper surface of the color filter glass layer under the upper polarizer. Reflections may be minimized by using index-matching dielectric layers in the display or thinning the shielding layer.

Abstract: A liquid crystal display (LCD) is provided having a discontinuous electrode. In certain embodiments, different portions (such as finger- or slit-like extensions) of the discontinuous electrode may be at different depths relative to one another and/or may be of different widths relative to one another. Similarly, in other embodiments, the different portions of the discontinuous electrode may be spaced apart in a non-uniform manner.

Abstract: A display may store extended display identification data for communicating the capabilities of the display to a source device such as a graphics processing unit. The extended display identification data may include a red primary color value, a green primary color value, and a blue primary color value. The primary color values in the extended display identification data may be determined during manufacturing. For example, a light sensor may measure the native primary colors of the display, and calibration computing equipment may determine if the native primary colors of the display are within a target color gamut. If the native primary colors of the display are outside of the target color gamut by an amount larger than a threshold, the primary color values in the extended display identification data may be adjusted to account for the color variation.

Abstract: A plasmonic detector and method for manufacturing a plasmonic detector. The plasmonic detector comprises two nanoscale metallic rods coupled to a bias voltage; a nanoscale cavity formed between adjacent ends of the two nanoscale metallic rods; and an absorption material disposed in the nanoscale cavity for converting an electromagnetic field to an electric current for outputting via the nanoscale metallic rods.

Abstract: A display is provided that has upper and lower polarizers, a color filter layer, a liquid crystal layer, and a thin-film transistor layer. The color filter layer and thin-film transistor layer may be formed from materials such as glass that are subject to stress-induced birefringence. To reduce light leakage that reduces display performance, one or more birefringence compensation layers may be incorporated into the display to help compensate for any birefringence effects. The compensation layers may include a birefringence compensation layer attached to the color filter layer or the thin-film transistor layer. A display may include an upper compensation layer attached to the color filter layer and a lower compensation layer attached to the thin-film transistor layer. The compensation layer may be formed from glass or polymer materials that have a negative photo-elastic constant.

Abstract: A display has an array of display pixels formed from display layers such as one or more polarizer layers, a substrate on which an array of display pixel elements such as color filter elements and downconverter elements are formed, a liquid crystal layer, and a thin-film transistor layer that includes display pixel electrodes and display pixel thin-film transistors for driving control signals onto the display pixel electrodes to modulate light passing through the display pixels. A light source such as one or more laser diodes or light-emitting diodes may be used to generate light for the display. The light may be launched into the edge of a polymer layer or other light guide plate structure. A light guide plate may include phase-matched structures such as holographically recorded gratings or photonic lattices that direct the light upwards through the array of display pixels.