Abstract: An electronic device display may have pixels formed from crystalline semiconductor light-emitting diode dies, organic light-emitting diodes, or other pixel structures. The pixels may be formed on a display panel substrate. A display panel may extend continuously across the display or multiple display panels may be tiled in two dimensions to cover a larger display area. Interconnect substrates may have outwardly facing contacts that are electrically shorted to corresponding inwardly facing contacts such as inwardly facing metal pillars associated with the display panels. The interconnect substrates may be supported by glass layers. Integrated circuits may be embedded in the display panels and/or in the interconnect substrates. A display may have an active area with pixels that includes non-spline pixels in a non-spline display portion located above a straight edge of the display and spline pixel in a spline display portion located above a curved edge of the display.

Abstract: A display may have an array of pixels such as liquid crystal display pixels. The display may include short pixel rows that span only partially across the display and full-width pixel rows that span the width of the display. The gate lines coupled to the short pixel rows may extend into the inactive area of the display. Supplemental gate line loading structures may be located in the inactive area of the display to increase loading on the gate lines that are coupled to short pixel rows. The supplemental gate line loading structures may include data lines and doped polysilicon that overlap the gate lines in the inactive area. In displays that combine display and touch functionality into a thin-film transistor layer, supplemental loading structures may be used in the inactive area to increase loading on common voltage lines that are coupled to short rows of common voltage pads.

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: A display may include pixels arranged in rows and columns in an active area and display driver circuitry in an inactive area. Data lines for the pixels may be positioned in the active area. Fanout lines may be routed through the active area. Each fanout line may electrically connect the display driver circuitry to a respective data line. One or more pixels may include a drive transistor and a light-emitting diode that are connected in series between a first power supply terminal and a second power supply terminal. A conductive layer may form a first terminal (such as the source terminal, the gate terminal, or the drain terminal) for the drive transistor. A conductive shielding layer may be interposed between the conductive layer and a fanout line to mitigate capacitive coupling between the terminal of the drive transistor and the fanout line.

Abstract: Electrical shield line systems are provided for openings in common electrodes near data lines of display and touch screens. Some displays, including touch screens, can include multiple common electrodes (Vcom) that can have openings between individual Vcoms. Some display screens can have an open slit between two adjacent edges of Vcom. Openings in Vcom can allow an electric field to extend from a data line through the Vcom layer. A shield can be disposed over the Vcom opening to help reduce or eliminate an electric field from affecting a pixel material, such as liquid crystal. The shield can be connected to a potential such that electric field is generated substantially between the shield and the data line to reduce or eliminate electric fields reaching the liquid crystal.

Abstract: A display may have an array of organic light-emitting diode display pixels operating at a low refresh rate. Each display pixel may have six thin-film transistors and one capacitor. One of the six transistors may serve as the drive transistor and may be compensated using the remaining five transistors and the capacitor. One or more on-bias stress operations may be applied before threshold voltage sampling to mitigate first frame dimming. Multiple anode reset and on-bias stress operations may be inserted during vertical blanking periods to reduce flicker and maintain balance and may also be inserted between successive data refreshes to improve first frame performance. Two different emission signals controlling each pixel may be toggled together using a pulse width modulation scheme to help provide darker black levels.

Abstract: To reduce the amount of space occupied in the inactive area of a display by gate driver circuitry, at least a portion of the gate driver circuitry may be positioned in the active area of the display. To accommodate the gate driver circuitry, emissive sub-pixels may be laterally shifted relative to corresponding thin-film transistor sub-pixels. This allows for the thin-film transistor sub-pixels to be grouped adjacent to the central area of the active area, leaving room along an edge of the active area to accommodate one or more additional display components such as gate driver circuitry or fanout portions of data lines.

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 include a display having display pixels formed in an active area of the display. The display further includes display driver circuitry for driving gate lines that are routed across the display. A hole such as a through hole, optical window, or other inactive region may be formed within the active area of the display. Multiple gate lines carrying the same signal may be merged together prior to being routed around the hole to help minimize the routing line congestion around the border of the hole. Dummy circuits may be coupled to the merged segment portion to help increase the parasitic loading on the merged segments. The hole may have a tapered shape to help maximize the size of the active area. The hole may have an asymmetric shape to accommodate multiple sub-display sensor components.

Abstract: A display may have an array of organic light-emitting diode display pixels operating at a low refresh rate. Each display pixel may have six thin-film transistors and one capacitor. One of the six transistors may serve as the drive transistor and may be compensated using the remaining five transistors and the capacitor. One or more on-bias stress operations may be applied before threshold voltage sampling to mitigate first frame dimming. Multiple anode reset and on-bias stress operations may be inserted during vertical blanking periods to reduce flicker and maintain balance and may also be inserted between successive data refreshes to improve first frame performance. Two different emission signals controlling each pixel may be toggled together using a pulse width modulation scheme to help provide darker black levels.

Abstract: A display may have organic light-emitting diode pixels formed from thin-film circuitry. The thin-film circuitry may be formed in thin-film transistor (TFT) layers and the organic light-emitting diodes may include anodes and cathodes and an organic emissive layer formed over the TFT layers between the anodes and cathodes. The organic emissive layer may be formed via chemical evaporation techniques. The display may include moisture blocking structures such as organic emissive layer disconnecting structures that introduce one or more gaps in the organic emissive layer during evaporation so that any potential moisture permeating path from the display panel edge to the active area of the display is completely terminated.

Abstract: An electronic device may include a display and an optical sensor formed underneath the display. The electronic device may include a plurality of transparent windows that overlap the optical sensor. The resolution of the display panel may be reduced in some areas due to the presence of the transparent windows. To mitigate diffraction artifacts, a first sensor (13-1) may sense light through a first pixel removal region having transparent windows arranged according to a first pattern. A second sensor (13-2) may sense light through a second pixel removal region having transparent windows arranged according to a second pattern that is different than the first pattern. The first and second patterns of the transparent windows may result in the first and second sensors having different diffraction artifacts. Therefore, an image from the first sensor may be corrected for diffraction artifacts based on an image from the second sensor.

Abstract: An electronic device may include a display having display pixels formed in an active area of the display. The display further includes display driver circuitry for driving gate lines that are routed across the display. A hole such as a through hole, optical window, or other inactive region may be formed within the active area of the display. Multiple gate lines carrying the same signal may be merged together prior to being routed around the hole to help minimize the routing line congestion around the border of the hole. Dummy circuits may be coupled to the merged segment portion to help increase the parasitic loading on the merged segments. The hole may have a tapered shape to help maximize the size of the active area. The hole may have an asymmetric shape to accommodate multiple sub-display sensor components.

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 both a full pixel density region and a pixel removal region with a plurality of high-transmittance areas that overlap an optical sensor. Each high-transmittance area may be devoid of thin-film transistors and other display components. To improve transmission while maintaining satisfactory touch sensing performance, one or more segments of the touch sensor metal in the pixel removal region may have a reduced width relative to the touch sensor metal in the full pixel density region and/or one or more segments of the touch sensor metal in the pixel removal region may be omitted relative to the touch sensor metal in the full pixel density region. To mitigate a different appearance between the pixel removal region and the full pixel density region at off-axis viewing angles, the position of the touch sensor metal in the pixel removal region may be tuned.

Abstract: A display may have both a full pixel density region and a pixel removal region with a plurality of high-transmittance areas that overlap an optical sensor. Each high-transmittance area may be devoid of thin-film transistors and other display components. To improve transmission while maintaining satisfactory touch sensing performance, one or more segments of the touch sensor metal in the pixel removal region may have a reduced width relative to the touch sensor metal in the full pixel density region and/or one or more segments of the touch sensor metal in the pixel removal region may be omitted relative to the touch sensor metal in the full pixel density region. To mitigate a different appearance between the pixel removal region and the full pixel density region at off-axis viewing angles, the position of the touch sensor metal in the pixel removal region may be tuned.

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.

Abstract: A display may have an array of pixels such as liquid crystal display pixels. The display may include short pixel rows that span only partially across the display and full-width pixel rows that span the width of the display. The gate lines coupled to the short pixel rows may extend into the inactive area of the display. Supplemental gate line loading structures may be located in the inactive area of the display to increase loading on the gate lines that are coupled to short pixel rows. The supplemental gate line loading structures may include data lines and doped polysilicon that overlap the gate lines in the inactive area. In displays that combine display and touch functionality into a thin-film transistor layer, supplemental loading structures may be used in the inactive area to increase loading on common voltage lines that are coupled to short rows of common voltage pads.

Abstract: An electronic device may have a display such as an organic light-emitting diode display. The organic light-emitting diode (OLED) display may have an array of organic light-emitting diode pixels that each have OLED layers interposed between a cathode and an anode. A first passivation layer, a first planarization layer, and a second passivation layer may be formed over the cathode. The first and second passivation layers may be formed from inorganic material. A second planarization layer may be formed over the second passivation layer between the second passivation layer and a polarizer. The second planarization layer may planarize the polarizer at the edges of the active area of the display where the polarizer would otherwise have a steep taper. Planarizing the polarizer in this way mitigates undesirable secondary reflections off of the polarizer. The first and second planarization layers may be formed from organic material.