Abstract:
A display may have an active area surrounded by a border area. 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. The liquid crystal layer may be retained within the display using a ring of sealant that is dispensed along the border area on the thin-film transistor layer. The thin-film transistor layer may include at least a substrate, a dielectric layer formed over the substrate, a first planarization layer formed on the dielectric layer, and a second planarization layer formed on the first planarization layer. A first continuous trench structure may be formed along the border of the display to help prevent moisture seepage. A second trench structure that is separate from the first trench structure may be formed along the border of the display to help provide proper sealant adhesion.
Abstract:
A display may have a thin-film-transistor layer with a substrate layer. A layer of dielectric may be formed on the substrate layer and may have an upper surface and a lower surface. The thin-film-transistor layer may include an array of display pixels. Data lines and gate lines may provide signals to the display pixels. Gate driver circuitry in an inactive peripheral portion of the display may include a gate driver circuit for each gate line. The gate driver circuits may include thin-film transistors that are formed on the upper surface of the layer of dielectric. Signal lines such as a gate low line, a gate routing line coupled between the gate driver circuits, and a common electrode line may be formed from two or more layers of metal to reduce their widths or may be embedded within the dielectric layer between the upper and lower surfaces under the thin-film transistors.
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:
A display may be provided with integral touch functionality. The display may include a common electrode layer having row electrodes arranged in rows and column electrodes interposed between the row electrodes of each row. The row electrodes may be electrically coupled by conductive paths. The row and column electrodes may be coupled to touch sensor circuitry that uses the row and column electrodes to detect touch events. Each electrode of the common electrode layer may cover a respective portion of an array of pixels. Each pixel of the display may have a respective aperture. The conductive paths that electrically couple row electrodes of the common electrode layer may cover or otherwise block some light from passing through pixels, resulting in reduced apertures. Dummy structures may be provided for other pixels that modify the apertures of the other pixels to match the reduced apertures associated with the conductive paths.
Abstract:
An electronic device display may have an array of display pixels that are controlled using a grid of data lines and gate lines. The display may include compact gate driver circuits that perform gate driver operations to drive corresponding gate lines. Each compact gate driver circuit may include a first driver stage and a second driver stage. The first driver stage may receive a start pulse signal and produce a control signal. The control signal may be stored by a capacitor to identify a control state of the gate driver circuit. The second driver stage may receive the control signal, a clock signal, and a corresponding inverted clock signal and drive the corresponding gate line based on the received signals. The second driver stage may include pass transistor circuitry that passes the clock signal to the corresponding gate line and may include short circuit protection circuitry.
Abstract:
A transistor that may be used in electronic displays to selectively activate one or more pixels. The transistor includes a metal layer, a silicon layer deposited on at least a portion of the metal layer, the silicon layer includes an extension portion that extends a distance past the metal layer, and at least three lightly doped regions positioned in the silicon layer. The at least three lightly doped regions have a lower concentration of doping atoms than other portions of the silicon layer forming the transistor.
Abstract:
To minimize the width of a non-light-emitting border region around an opening in the active area, data lines may be stacked in the border region. Data line portions may be formed using three metal layers in three different planes within the border region. A metal layer that forms a positive power signal distribution path in the active area may serve as a data line portion in the border region. A metal layer may be added in the border region to serve as a data line portion in the border region. Data line signals may also be provided to pixels on both sides of an opening in the active area using supplemental data line paths. A supplemental data line path may be routed through the active area of the display to electrically connect data line segments on opposing sides of an opening within the display.
Abstract:
An electronic device may have a display with an active area configured to display images and an inactive area that is free of pixels and that does not display images. Touch sensor sense lines may have portions located in the active area and portions located in the inactive area. The active and inactive areas may be characterized by respective reflectivity values. To match the reflectivities of the active and inactive areas and thereby avoid undesired visually distinguishable differences in the appearances of these areas, the touch sensor circuitry in the inactive areas may be configured to match the reflectivity values of the active and inactive areas. Sense line portions in the inactive area may have metal traces of enhanced reflectivity and/or uneven surface topology to enhance ambient light reflections through a circular polarizer that overlaps the active and inactive areas.
Abstract:
A display may have rows and columns of pixels. Gate lines may be used to supply gate signals to rows of the pixels. Data lines may be used to supply data signals to columns of the pixels. The data lines may include alternating even and odd data lines. Data lines may be organized in pairs each of which includes one of the odd data lines and an adjacent one of the even data lines. Demultiplexer circuitry may be configured dynamically during data loading and pixel sensing operations. During data loading, data from display driver circuitry may be supplied, alternately to odd pairs of the data lines and even pairs of the data lines. During sensing, the demultiplexer circuitry may couple a pair of the even data lines to sensing circuitry in the display driver circuitry and then may couple a pair of the odd data lines to the sensing circuitry.
Abstract:
To minimize the width of a non-light-emitting border region around an opening in the active area, data lines may be stacked in the border region. Data line portions may be formed using three metal layers in three different planes within the border region. A metal layer that forms a positive power signal distribution path in the active area may serve as a data line portion in the border region. A metal layer may be added in the border region to serve as a data line portion in the border region. Data line signals may also be provided to pixels on both sides of an opening in the active area using supplemental data line paths. A supplemental data line path may be routed through the active area of the display to electrically connect data line segments on opposing sides of an opening within the display.