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 light-emitting diodes may be inorganic light-emitting diodes formed from separate crystalline semiconductor structures. An array of pixel control circuits may be used to control light emission from the light-emitting diodes. Each pixel control circuit may be used to supply drive signals to a respective set of the light-emitting diodes. The pixel control circuits may each have a silicon integrated circuit that includes transistors such as emission enable transistors and drive transistors for supplying the drive signals and may each have thin-film semiconducting oxide transistors that are coupled to the integrated circuit and that serve as switching transistors.

Abstract: A display may have a thin-film transistor layer formed from a layer of thin-film, transistor circuitry on a substrate. The thin-film transistor layer may overlap a color filter layer. A portion of the thin-film transistor layer may extend past the color filter layer to for a ledge region. Components such as a flexible printed circuit and a display driver integrated circuit may be mounted to the thin-film transistor layer in the ledge region. The components may have alignment marks. The thin-film transistor layer may have a black masking layer that is patterned to form openings for display pixels. In a border area of the display that overlaps the ledge region, the thin-film transistor layer may have alignment mark viewing windows. Alignment marks formed from black masking material in the windows may be aligned with respective alignment marks on the components.

Abstract: A liquid crystal display may have a thin-film transistor layer with an array of pixel electrode structures for applying electric fields to a liquid crystal layer. The liquid crystal display may also have a color filter layer with an array of color filter elements. The color filter elements may allow the display to display color images. The color filter layer may be interposed between the thin-film transistor layer and a backlight. The liquid crystal layer may be sandwiched between the thin-film transistor layer and the color filter layer. The color filter layer may have a transparent substrate on which the color filter elements are formed. Black masking structures may be formed on a transparent overcoat layer that covers the color filter elements. Black column spacers may be formed from the same layer of material that forms the black masking structures.

Abstract: A display may have a first stage such as a color liquid crystal display stage and a second stage such as a monochromatic liquid crystal display stage that are coupled in tandem so that light from a backlight passes through both stages. The first (upper) stage may be a high resolution display panel that is operated at a first refresh rate while the second (lower) stage is a low resolution display panel that is operated at a second refresh rate that is greater than the first refresh rate. In particular, the second stage may be configured to provide localized dimming that is synchronized to one or more moving objects in the video frames to be displayed to help reduce the perceived motion blur. The localized dimming may be provided via insertion of a black image portion that only overlaps with the moving objects, a blanking row that tracks the moving objects, a black frame, etc.

Abstract: Systems and electronic displays with improved contrast even under bright-light conditions are provided. Such an electronic display may include a self-emissive pixel (e.g., OLED or ?-LED) with a corresponding liquid crystal switchable retarder pixel. A liquid crystal layer of the switchable retarder pixel may be tuned to an “on” state or an “off” state. In the “on” state, the switchable retarder pixel may allow outside light that enters the pixel to reflect back out of the pixel. This may add to the amount of light that appears to be emitted from that pixel. In the “off” state, the switchable retarder pixel may block the outside light that enters the pixel from reflecting back out of the pixel. This may reduce the amount of light that appears to be emitted from that pixel. Selectively controlling the switchable retarder pixels may allow for increased contrast even under bright-light conditions.

Abstract: A touch screen having layers. The touch screen can include a substrate upon which the layers of the touch screen are disposed, and a touch region including a touch pixel electrode, a first display sub-pixel and a second display sub-pixel. The touch screen can also include a sense connection coupled to touch sensing circuitry. An intermediate connection can be disposed between the touch pixel electrode and the sense connection, and can be coupled to the sense connection at the first display sub-pixel and the touch pixel electrode at the second display sub-pixel. In some examples, the sense connection can be disposed at least partially underneath a structure in the first display sub-pixel, such as a data line. In some examples, the intermediate connection can be comprised of a same material type as a structure in the first display sub-pixel, such as a gate line material.

Abstract: An electronic device may include a display having an array of display pixels on a substrate. The display pixels may be organic light-emitting diode display pixels or display pixels in a liquid crystal display. In an organic light-emitting diode display, hybrid thin-film transistor structures may be formed that include semiconducting oxide thin-film transistors, silicon thin-film transistors, and capacitor structures. The capacitor structures may overlap the semiconducting oxide thin-film transistors. Organic light-emitting diode display pixels may have combinations of oxide and silicon transistors. In a liquid crystal display, display driver circuitry may include silicon thin-film transistor circuitry and display pixels may be based on oxide thin-film transistors. A single layer or two different layers of gate metal may be used in forming silicon transistor gates and oxide transistor gates. A silicon transistor may have a gate that overlaps a floating gate structure.

Abstract: Embodiments of the present disclosure relate to display devices and electronic devices incorporating a data line distribution segment between neighboring pixel electrodes. Specifically, embodiments of the present disclosure employ a uniformly distributed data line distribution segment coupled to a data line so as to cause a substantially uniform data line-to-pixel electrode capacitance with the neighboring pixel electrodes even when the data line is disposed closer to one of the neighboring pixel electrodes than the other.

Abstract: A touch screen display may include gate line driver circuitry coupled to a display pixel array. The display may be provided with intra-frame pausing (IFP) capabilities, where touch or other operations may be performed during one or more intra-frame blanking intervals. In one suitable arrangement, a gate driver circuit may include multiple gate line driver segments each of which is activated by a separate gate start pulse. Each gate start pulse may only be released at the end of an IFP interval. In another suitable arrangement, dummy gate driver units may be interposed among active gate driver units. Gate output signals may propagate through the dummy gate driver units during the IFP internal. In another suitable arrangement, each active gate driver unit may be provided with a buffer portion that protects at least some transistor in the gate driver unit from undesired stress.

Abstract: A display may have an array of pixels formed from organic light-emitting diodes and thin-film transistor circuitry. A planarization layer may be interposed between the thin-film transistor circuitry and the organic light-emitting diodes. To protect the organic light-emitting diodes from photoactive compounds that may be outgassed from the planarization layer, an inorganic barrier layer may be interposed between the planarization layer and the organic light-emitting diodes. The inorganic barrier layer may be formed on top of and/or below a pixel definition layer that defines light-emitting zones for the organic light-emitting diodes. In another suitable arrangement, the inorganic barrier layer may itself define light-emitting zones and may be used in place of a polymer-based pixel definition layer. The inorganic barrier layer may include trenches in which the emissive material of the light-emitting diodes is formed.

Abstract: The border routing of conductive traces in devices, such as displays, touch sensor panels, and touch screens, to improve border area space usage, thereby reducing device size, and to reduce trace resistance, thereby improving device operation, is disclosed. The conductive traces can form a staggered stair-step configuration in the device border area, in which the average widths of the traces can be different from each other and each trace can have segments with different widths. The conductive traces can be coupled to an active area of the device to transmit signals to and from the active area in accordance with a device operation. The varying widths can help improve the border area space usage, reduce trace resistance, and reduce the differences in resistance between traces.

Abstract: An electronic device display may have a color filter layer, a thin-film-transistor layer, and a layer of liquid crystal material. The display may have a display cover layer such as a layer of glass or plastic. Adhesive may be used to attach the upper polarizer to the display cover layer. The thin-film transistor layer may have a substrate with upper and lower surfaces. Thin-film-transistor circuitry may be formed on the upper surface. A display driver integrated circuit may be mounted to the lower surface or a flexible printed circuit and may be coupled to the thin-film-transistor circuitry using wire bonding wires. Through vias that are formed through the thin-film-transistor layer substrate may be used in coupling the thin-film-transistor circuitry to the display driver integrated circuit.

Abstract: A display may have an array of pixels. Each pixel may have a light-emitting diode that emits light under control of a drive transistor. The organic light-emitting diodes may have a common cathode layer, a common electron layer, individual red, green, and blue emissive layers, a common hole layer, and individual anodes. The hole layer may have a hole injection layer stacked with a hole transport layer. Pixel circuits for controlling the diodes may be formed from a layer of thin-film transistor circuitry on a substrate. A planarization layer may cover the thin-film transistor layer. Lateral leakage current between adjacent diodes can be blocked by shorting the common hole layer to a metal line such as a bias electrode that is separate from the anodes. The metal line may be laterally interposed between adjacent pixels and may be formed on the planarization layer or embedded within the planarization layer.

Abstract: A display is provided that includes an array of display pixels and gate driver circuitry for providing data and gate line signals to the display pixels. Gate driver circuitry may include gate driver circuits that generate the gate line signals. A gate driver circuit may include at least a buffer transistor, a bootstrapping capacitor coupled to the buffer transistor, a pulldown transistor coupled in series with the buffer transistor, and an isolation transistor coupled to the gate of the pulldown transistor. The buffer transistor may directly receive a first clock signal, whereas the isolation transistor may directly receive a second clock signal that is complementary to the first clock signal. The pulldown transistor is substantially larger than the buffer transistor. The buffer transistor is substantially larger than the isolation transistor. Configured as such, clock loading is minimized while the pulldown transistor is sized to provide the desired fall time performance.

Abstract: A method is provided for fabricating thin-film transistors (TFTs) for an LCD having an array of pixels. The method includes depositing a first photoresist layer over a portion of a TFT stack. The TFT stack includes a conductive gate layer, and a semiconductor layer. The method also includes doping the exposed semiconductor layer with a first doping dose. The method further includes etching a portion of the conductive gate layer to expose a portion of the semiconductor layer, and doping the exposed portion of the semiconductor layer with a second doping dose. The method also includes removing the first photoresist layer, and depositing a second photoresist layer over a first portion of the doped semiconductor layer in an active area of the pixels to expose a second portion of the doped semiconductor layer in an area surrounding the active area.

Abstract: A display may have a color filter layer and a thin-film transistor layer. A layer of liquid crystal material may be located between the color filter layer and the thin-film transistor (TFT) layer. The TFT layer may include thin-film transistors formed on top of a glass substrate. A passivation layer may be formed on the thin-film transistor layers. A first low-k dielectric layer may be formed on the passivation layer. Data line routing structures may be formed on the first low-k dielectric layer. A second low-k dielectric layer may be formed on the first low-k dielectric layer. A common voltage electrode and associated storage capacitance may be formed on the second low-k dielectric layer. The first and second low-k dielectric layers may be formed from material having substantially similar refractive indices to maximize backlight transmittance and may have appropriate thicknesses so as to minimize parasitic capacitive loading.

Abstract: A display may have a thin-film transistor (TFT) layer and color filter layer. Light blocking structures in an inactive area of the display may prevent stray backlight from leaking out of the display. The thin-film transistor layer may have a first substrate, a first black masking layer, a planarization layer, and a layer of TFT circuitry on the planarization layer. The color filter layer may have a second substrate and a second black masking layer on the second substrate. Light-cured sealant may be formed between the TFT layer and the color filter layer. Gaps may be formed in the second black masking layer to allow light to cure the sealant. At least a portion of the TFT circuitry may serve to block stray backlight penetrating through the gaps in the second black masking layer during normal operation of the display.

Abstract: An electronic device may have a flexible display. The display may have portions that are bent along a bend axis. The display may have display circuitry such as an array of display pixels in an active area and signal lines, thin-film transistor support circuitry and other display circuitry in an inactive area of the display surrounding the active area. The display circuitry may be formed on a substrate such as a flexible polymer substrate. The flexible polymer substrate may be formed by depositing polymer on a support structure that has raised portions. The raised portions may create locally thinned regions in the flexible polymer substrate. The reduced thickness of the flexible polymer substrate in the thinned regions may help ensure that a neutral stress plane that is associated with bending the display along the bend axis is aligned with the display circuitry, thereby minimizing stress in the display circuitry.

Abstract: A display may have an array of pixels. The array of pixels may have a shape such as a circular shape or other shape with a curved edge. Display driver circuitry may supply data signals to the pixels using folded vertical data lines and bisected horizontal gate lines. Each folded vertical lines may have a first segment in a left half of the array and a second segment in a right half of the display. Curved coupling segments in an inactive area of the display may be used in joining the first and second segments. Display driver circuits may be provided in top and bottom portions of the inactive area to supply data to respective top and bottom portions of the array. Gate driver output buffers may have different strengths in different rows of the array.

Abstract: A display may have an array of pixels controlled by display driver circuitry. The display driver circuitry may supply the pixels with data signals over data lines in columns of the pixels and may supply the pixels with gate line signals over gate lines in rows of the pixels. The display driver circuitry may have a display driver integrated circuit located on one of the edges of the display. The display driver circuitry may also have gate driver integrated circuits that extend along opposing edges of the display to form a pair of shift registers. Conductive lines in a display substrate may be coupled to opposing ends of the shift registers and to intermediate locations within the shift registers to minimize delays in distributing a gate high voltage signal from the display driver integrated circuit to the shift registers.