Abstract: Electronic devices may include displays having organic light-emitting diode pixels, display driver circuitry, and gate driver circuitry. To reduce the amount of space occupied in the inactive area of a display by the gate driver circuitry, one or more of the shift registers in the gate driver circuitry may include register circuits that are shared by multiple rows of pixels. Different drivers may use different clock frequencies to ensure synchronous operation of the display even when some register circuits share pixel rows. For increased flexibility in the arrangement of the register circuits in the shift registers, one or more of the shift registers may be split across the active area of the display. In some cases, one of the emission drivers may be omitted from the gate driver circuitry and a single emission driver may provide multiple emission control signals for the pixels.

Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.

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 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: Electronic devices, storage medium containing instructions, and methods pertain to cancelling noise that results from application of clocks/clock drivers of a display. The electronic display may inject counter noise into the cathode. For example, the counter noise may be injected via a sensing layer, via unused clocks, and/or via a power rail of the display.

Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.

Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.

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 organic light-emitting diode display may have rounded corners. A negative power supply path may be used to distribute a negative voltage to a cathode layer, while a positive power supply path may be used to distribute a positive power supply voltage to each pixel in the display. The positive power supply path may have a cutout that is occupied by the negative power supply path to decrease resistance of the negative power supply path in a rounded corner of the display. To mitigate reflections caused by the positive power supply path being formed over tightly spaced data lines, the positive power supply path may be omitted in a rounded corner of the display, a shielding layer may be formed over the positive power supply path in the rounded corner, or non-linear gate lines may be formed over the positive power supply path.

Abstract: A display may have an array of organic light-emitting diode display pixels operating at a low refresh rate. Each display pixel may include a drive transistor coupled in series with one or more emission transistors and a respective organic light-emitting diode (OLED). A semiconducting-oxide transistor may be coupled between a drain terminal and a gate terminal of the drive transistor to help reduce leakage during low-refresh-rate display operations. A silicon transistor may be further interposed between the semiconducting-oxide transistor and the gate terminal of the drive transistor. One or more capacitor structures may be coupled to the source terminal and/or the drain terminal of the semiconducting-oxide transistor to reduce rebalancing current that might flow through the semiconducting-oxide transistor as it is turned off. Configured in this way, any emission current flowing through the OLED will be insensitive to any potential drift in the threshold voltage of the semiconducting-oxide transistor.

Abstract: A display may have an array of organic light-emitting diode display pixels operating at a low refresh rate. Each display pixel may include a drive transistor coupled in series with one or more emission transistors and a respective organic light-emitting diode (OLED). A semiconducting-oxide transistor may be coupled between a drain terminal and a gate terminal of the drive transistor to help reduce leakage during low-refresh-rate display operations. A silicon transistor may be further interposed between the semiconducting-oxide transistor and the gate terminal of the drive transistor. One or more capacitor structures may be coupled to the source terminal and/or the drain terminal of the semiconducting-oxide transistor to reduce rebalancing current that might flow through the semiconducting-oxide transistor as it is turned off. Configured in this way, any emission current flowing through the OLED will be insensitive to any potential drift in the threshold voltage of the semiconducting-oxide transistor.

Abstract: An electronic device may include a display such as a light-emitting diode display. The electronic device may be a head-mounted device that provides a virtual reality or augmented reality environment to a user. To reduce artifacts in the display, a display may be operable in both a normal scanning mode and a partial scanning mode. In the normal scanning mode, every row of the display may be enabled to emit light in each frame. In the partial scanning mode, only a subset of the rows of the display may be enabled to emit light in each frame. The display may have a higher refresh rate in the partial scanning mode than in the normal scanning mode. To ensure uniform transistor stress across the display, the scanning driver for the display may scan the disabled rows in the partial scanning mode even though the rows will not be used to emit light.

Abstract: Aspects of the subject technology relate to display circuitry. The display circuitry includes gate-in-panel (GIP) control circuitry on opposing sides of a display pixel array. The GIP control circuitry can include scan drivers for each pixel row on both sides of that pixel row, the scan drivers on either side configured for enablement or disablement for single-sided reduced-power operations. The GIP control circuitry can include a single scan driver and a single emission controller for each pixel row, in which the scan driver and emission controller for each row are disposed on opposing sides of the row. The scan drivers for a first subset of the pixel rows can be interleaved with the emission controllers for a different subset of the pixel rows.

Abstract: A touch sensitive device that can detect the amount of pressure being applied to a touch screen from a user or other external object is provided. A spacer of the touch screen can be coated with a layer of conductive material and the change in capacitance between the spacer and various circuit elements of the touch screen can be measured. The change in capacitance can be correlated to the amount of pressure being applied to the touch screen, thus providing a method to determine the pressure being applied. During operation of the device, the system can time multiplex touch, display and pressure sensing operations so as to take advantage of an integrated touch and display architecture.

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 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: 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 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: Methods and devices useful in discharging an aberrant charge on the VCOM of an electronic display and harvesting energy from the VCOM of the electronic display are provided. By way of example, a method may include supplying an activation signal to an active switching device of an electronic display. The active switching device is configured to discharge an aberrant charge on a common electrode of the electronic display. The method further includes discharging the aberrant charge by way of the active switching device. Discharging the aberrant charge comprises preventing a possible occurrence of image artifacts from becoming apparent on the electronic display.

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.