Abstract:
An electronic device may be provided with a display mounted in a housing. The display may include a liquid crystal display module and a reflective polarizer having an in-plane optical axis. The display may also include a backlight unit that includes a light source, a light guide element, and a reflector film coupled to a backside of the light guide element. The display may also include a light retardation layer such as a quarter wave film. The quarter wave film may be arranged between the reflective polarizer and the reflector film of the backlight unit. Partially polarized light that is output from a front side of the light guide element may have a first component parallel to the in-plane optical axis and a second component perpendicular to the in-plane optical axis of the reflective polarizer. The second component may be reflected from the reflective polarizer.
Abstract:
An electronic device may be provided with a display mounted in a housing. A color sensing ambient light sensor may measure the color of ambient light. The color sensing ambient light sensor may produce sensor output signals in a device-dependent color space. Control circuitry in the electronic device may convert the sensor output signals from the device-dependent color space to a device-independent color space using a color converting matrix. The color converting matrix may be determined using stored training data. The training data may include color data for different training light sources. The training data may be weighted to selectively control the influence of the training data on the color converting matrix. The training data may be weighted based on a distance between the training color data and a target color in the detected ambient light.
Abstract:
A display may have an array of pixels formed from organic light-emitting diodes of different colors. Each organic light-emitting diode may have an anode, a cathode, and an emissive layer between the anode and cathode. To prevent undesired color shifts with off-axis viewing angles, evaporated color filters may be formed on the cathode in alignment with the light-emitting diodes. The color filters may include red color filters that overlap the red diodes but not the green and blue diodes, may include red, blue, and green filters that overlap respective red, green, and blue diodes, or may include an orange filter that overlaps red and green diodes and a blue filter that overlaps blue diodes. The color filters may serve as a capping layer for the diodes or a capping layer that is separate from the color filters can be incorporated into the display.
Abstract:
An electronic device may generate content that is to be displayed on a display. The display may have an array of pixels each of which includes subpixels of different colors. The content that is to be displayed on the display may include an object such as a black object that is moved across a background. Due to differences in subpixel values in the background for subpixels of different colors, there is a potential for color motion blur to develop along a trailing edge portion of the object as the object is moved across the background. The electronic device may have a blur abatement image processor that processes the content to reduce color motion blur. The blur abatement image processor may identify which pixels are located in the trailing edge and may adjust subpixel values for pixels in the trailing edge.
Abstract:
An electronic device may have a liquid crystal display having a backlight and color mixing prevention structures. The color mixing prevention structures may, in part, be formed from one or more arrays of color filter elements. The liquid crystal display may include first and second transparent substrate layers on opposing sides of a liquid crystal layer. The display may include a first array of color filter elements on the first transparent substrate layer and a second array of color filter elements on the second transparent substrate layer. One or more of the arrays of color filter elements may include a black matrix formed over portions of the color filter elements. The color filter elements may fill or partially fill openings in the black matrix. The display may include a collimating layer on the second transparent substrate layer. The color filter elements may include cholesteric color filter elements.
Abstract:
An electronic device may include a display having an array of display pixels and having display control circuitry that controls the operation of the display. The display control circuitry may adaptively adjust the display output based on ambient lighting conditions. For example, in cooler ambient lighting conditions such as those dominated by daylight, the display may display neutral colors using a relatively cool white. When the display is operated in warmer ambient lighting conditions such as those dominated by indoor light sources, the display may display neutral colors using a relatively warm white. Adapting to the ambient lighting conditions may ensure that the user does not perceive color shifts on the display as the user's vision chromatically adapts to different ambient lighting conditions. Adaptively adjusting images in this way can also have beneficial effects on the human circadian rhythm by displaying warmer colors in the evening.
Abstract:
An active matrix liquid crystal display having an array of pixels is provided. The display includes a thin film transistor (TFT) for each pixel. The TFT has a gate electrode, a source electrode overlapping with a first area of the gate electrode, and a drain electrode overlapping with a second area with the gate electrode. The display also includes a color filter layer disposed over the TFT. The color filter layer has a first via hole to expose a portion of the drain electrode. The display further includes a metal layer disposed over the color filter layer and covering the gate electrode. The metal layer is configured to connect to the drain electrode through the first via hole. The display also includes an organic insulator layer disposed over the metal layer. The organic insulator layer has a second via hole to expose a first portion of the metal layer and a third via hole to expose a second portion of the metal layer.
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:
An electronic device may be provided with a display such as a liquid crystal display. The liquid crystal display may have a color filter layer, a thin-film-transistor layer, and a layer of liquid crystal material between the color filter layer and the thin-film-transistor layer. A lower polarizer may be formed under the thin-film-transistor layer. An upper polarizer may be formed on the color filter layer. A shielding antireflection layer may be formed on the upper polarizer. The shielding antireflection layer may serve both as a shielding layer that protects against display damage due to electrostatic charge and as an antireflection coating that helps to minimize reflections from the surface of the display. The shielding antireflection layer may include low and high index of refraction layers and a conductive layer such as a transparent conductive oxide layer that provides shielding.
Abstract:
A display may have an active area surrounded by an inactive border area. The inactive border area may be provided with an opaque masking material. The display may be a liquid crystal display having a liquid crystal layer sandwiched between a color filter layer and a thin-film transistor layer. Upper and lower polarizers may be provided above and below the color filter and thin-film transistor layers. The upper polarizer may have a polarized central region that overlaps the active area of the display. The upper polarizer may also have an unpolarized portion in the inactive border area overlapping the opaque masking material. The opaque masking material may alternatively be formed on the underside of a clear polymer substrate that is attached to the display above the upper polarizer or may be incorporated within the layers that make up the upper polarizer.