Abstract:
Display driver circuitry may load data into an array of pixels via data lines. The display driver circuitry may supply control signals including scan signals to the pixels via control lines. Each pixel may have transistors and capacitor circuitry for controlling the emission of light from a light-emitting diode. A drive transistor may be coupled in series with the light-emitting diode to control the amount of current flowing through the light-emitting diode. The drive transistor may have a drive transistor gate terminal that is coupled to one of the source-drain terminals of a switching transistor. The switching transistor may have a switching transistor gate terminal that receives the scan signal. When transitioning prior to an emission phase of operation, the scan signal may have a two-step transition profile or other shape that enhances display performance by reducing dynamic effects in the switching transistor.
Abstract:
A display may have an array of organic light-emitting diode display pixels. Each display pixel may have a light-emitting diode that emits light under control of a drive transistor. Each display pixel may also have control transistors for compensation and programming operations. 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. The capacitor may have a first terminal coupled to the gate of the drive transistor and a second terminal coupled to the light-emitting diode. In one embodiment, two scan control signals and two emission control signals may be used for each row of display pixels. In another embodiment, a single scan control signal and a single emission control signal may be formed for each row of display pixels.
Abstract:
A display may have an array of organic light-emitting diode display pixels. Each display pixel may have a light-emitting diode that emits light under control of a drive transistor. Each display pixel may also have control transistors for compensation and programming operations. 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. The capacitor may have a first terminal coupled to the gate of the drive transistor and a second terminal coupled to the light-emitting diode. In one embodiment, two scan control signals and two emission control signals may be used for each row of display pixels. In another embodiment, a single scan control signal and a single emission control signal may be formed for each row of display pixels.
Abstract:
A display may have an array of organic light-emitting diode display pixels. Each display pixel may have a light-emitting diode that emits light under control of a drive transistor. Each display pixel may also have control transistors for compensating and programming operations. The array of display pixels may have rows and columns. Row lines may be used to apply row control signals to rows of the display pixels. Column lines (data lines) may be used to apply display data and other signals to respective columns of display pixels. A bottom conductive shielding structure may be formed below each drive transistor. The bottom conductive shielding structure may serve to shield the drive transistor from any electric field generated from the adjacent row and column lines. The bottom conductive shielding structure may be electrically floating or coupled to a power supply line.
Abstract:
An electronic device may be provided with an organic light-emitting diode display. The display may include row driver circuitry that provides an emission control signal at an output terminal to display pixels. The emission control signals may enable or disable light emission by the pixels. The row driver circuitry may include a bootstrapping capacitor that stores charge for boosting a gate signal at an intermediate node for a pull-up transistor above a power supply voltage. The row driver circuitry may include a pull-down transistor coupled to the intermediate node. The source terminal of the pull-down transistor may be coupled to the output terminal or an additional pull-down transistor may be stacked with the pull-down transistor to reduce leakage current. Charge pump circuitry may be coupled to the intermediate node to ensure that the intermediate node is maintained at a voltage above the power supply voltage.
Abstract:
An electronic device may be provided with an organic light-emitting diode display. The display may include row driver circuitry that provides an emission control signal at an output terminal to display pixels. The emission control signals may enable or disable light emission by the pixels. The row driver circuitry may include a bootstrapping capacitor that stores charge for boosting a gate signal at an intermediate node for a pull-up transistor above a power supply voltage. The row driver circuitry may include a pull-down transistor coupled to the intermediate node. The source terminal of the pull-down transistor may be coupled to the output terminal or an additional pull-down transistor may be stacked with the pull-down transistor to reduce leakage current. Charge pump circuitry may be coupled to the intermediate node to ensure that the intermediate node is maintained at a voltage above the power supply voltage.
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 include an active area with a first region and a second region. The first region may overlap an input-output component such as a camera and may have a higher transparency than the second region. The first region may have a lower pixel density than the second region. Signal lines that pass through the first region may have transparent portions that overlap the first region and opaque portions that overlap the second region. To mitigate artifacts caused by high resistance of the transparent portions of the signal lines, the signal lines may include supplemental opaque portions that are electrically connected in parallel to the transparent portions and that are routed through the second region around the first region.
Abstract:
A light emitter that operates through a display may cause display artifacts, even when the light emitter operates using non-visible wavelengths. To mitigate artifacts caused by a light emitter operating through a display, the display may have a higher density of thin-film transistor sub-pixels than emissive sub-pixels. This allows for a region in the display to include emissive sub-pixels but be free of thin-film transistor sub-pixels. The light emitter may operate through this region in the display. Additionally, 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.
Abstract:
A light emitter that operates through a display may cause display artifacts, even when the light emitter operates using non-visible wavelengths. To mitigate artifacts caused by a light emitter operating through a display, the display may have a higher density of thin-film transistor sub-pixels than emissive sub-pixels. This allows for a region in the display to include emissive sub-pixels but be free of thin-film transistor sub-pixels. The light emitter may operate through this region in the display. Additionally, 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.