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 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 include an array of pixels. Each pixel in the array includes an organic light-emitting diode coupled to a drive transistor, a data loading transistor, a first capacitor for storing data charge, and a second capacitor. During a data programming phase, the data loading transistor may be activated to load in a data value onto the first capacitor. After the data programming phase, the second capacitor may be configured to receive a lower voltage, which extends a threshold voltage sampling time for the pixel. Configured and operated in this way, the temperature luminance sensitivity of the display can be reduced.
Abstract:
An electronic device may include a display with pixels formed using light-emitting diodes, thin-film silicon transistors, thin-film semiconducting-oxide transistors, and capacitors. The silicon transistors, semiconducting-transistors, and capacitors may have control terminals that are coupled to gate or routing lines that extend across the face of the display and that are formed in a low resistance source-drain metal routing layer. Forming routing/gate lines using the low resistance source-drain metal routing layer dramatically reduces the resistance of the gate lines, which enables better timing margins for large display panels operating at higher refresh rates.
Abstract:
Electronic devices, stored instructions, and methods for delaying operations that may increase a length of time used to charge a battery. The operations may include, for example, display off-time sensing that detect aging of a display while the display is off to set compensation values for operation of the display the next time the display is on. By delaying the operations until battery charging transitions into a reduced current consumption, the battery charging may occur more quickly that if such operations are performed during a higher current demand since reduced current availability may greatly increase a duration of time used to charge the battery in the higher current demand portion of the battery charging.
Abstract:
An electronic device (10) comprises a display (12) and a controller (58). The controller (58) is configured to determine a change in a refresh rate of the display (1)2 from a first frequency to a second frequency. The controller (58) is also configured to selectively generate a control signal configured to control emission of a light emitting diode (54) of a display pixel (40) of the display (12) based on the first frequency.
Abstract:
A display may include an array of pixels. Each pixel in the array includes an organic light-emitting diode coupled to associated semiconducting oxide transistors. The semiconducting oxide transistors may exhibit different device characteristics. Some of the semiconducting oxide transistors may be formed using a first oxide layer formed from a first semiconducting oxide material using first processing steps, whereas other semiconducting oxide transistors are formed using a second oxide layer formed from a second semiconducting oxide material using second processing steps different than the first processing steps. The display may include three or more different semiconducting oxide layers formed during different processing steps.
Abstract:
A display pixel may include an organic light-emitting diode, one or more emission transistors, a drive transistor, a gate setting transistor, a data loading transistor, and an initialization transistor. The drive transistor may be implemented as a semiconducting-oxide transistor to mitigate threshold voltage hysteresis to improve first frame response at high refresh rates, to reduce undesired luminance jumps at low refresh rates, and to reduce image sticking. The gate setting transistor may also be implemented as a semiconducting-oxide transistor to reduce leakage at the gate terminal of the drive transistor. The initialization transistor may also be implemented as a semiconducting-oxide transistor so that it can be controlled using a shared emission signal to reduce routing complexity. The remaining transistors in the pixel may be implemented as p-type silicon transistors. Display pixels configured in this way can support in-pixel threshold voltage compensation and on-bias stress phase to further mitigate the hysteresis.
Abstract:
A display may include an array of organic light-emitting diode display pixels having transistors characterized by threshold voltages subject to transistor variations. Compensation circuitry may be used to measure a transistor threshold voltage for a pixel. The threshold voltage may be sampled by controlling the pixel to sample the threshold voltage onto a capacitor at the pixel. The pixel may include at least one semiconducting-oxide transistor, silicon transistors, and a light-emitting diode. The diode may be coupled to a data line that can be used for both data loading and compensation sensing operations. Reset operations may be performed after data programming and before emission to reset the anode voltage for the diode.
Abstract:
A display has rows and columns of pixels (22). A data line (Dn) in each column provides image data signals to the pixels of that column. Each row has first and second control lines (select[m], monitor[m]) coupled to the gates of first and second respective transistors (SE, MO) in each pixel. A third transistor in each pixel servea as a drive transistor (DR) and is coupled in series with a light-emitting diode (30) between positive and ground power supply voltages (VDD, VSS). A display driver circuitry in the display characterizes each of the light-emitting diodes in a column using the data line in an adjacent column from that light-emitting diode. Each of the drive transistors in a column is characterized using the data line in that column and the data line in an adjacent column.