A pixel circuit and a display device including the same are disclosed. The pixel circuit includes a driving element including a first electrode connected to a first node to which a pixel driving voltage is applied, a gate electrode connected to a second node, and a second electrode connected to a third node, and configured to supply an electric current to a light emitting element; a first switch element discharging the second node; and a second switch element configured to supply a data voltage to the second node. The light emitting element and the first switch element are commonly connected to a VSS node to which a low-potential power supply voltage is applied.

A display device includes pixels connected to scan lines, sensing lines, readout lines, and data lines; a scan driver including stages to supply a scan signal and a sensing signal to the scan lines and the sensing lines; a data driver which supplies a data signal to the data lines; a timing controller which divides one frame into an active period including a scan period in which the data signal is supplied to the data lines and a display period in which the pixels emit light in response to the data signal, and a blank period including a sensing period in which electrical characteristics of the pixels are detected and a reset period in which the stages are reset; and a compensator which generates a compensation value for compensating for deterioration of the pixels based on sensing values provided from the readout lines during the sensing period.

Methods and systems to provide baseline measurements for aging compensation for a display device are disclosed. An example display system has a plurality of active pixels and a reference pixel. Common input signals are provided to the reference pixel and the plurality of active pixels. The outputs of the reference pixel is measured and compared to the output of the active pixels to determine aging effects. The display system may also be tested applying a first known reference current to a current comparator with a second variable reference current and the output of a device under test such as one of the pixels. The variable reference current is adjusted until the second current and the output of the device under test is equivalent of the first current. The resulting current of the device under test is stored in a look up table for a baseline for aging measurements during the display system operation. The display system may also be tested to determine production flaws by determining anomalies such as short circuits in pixel components such as OLEDs and drive transistors.

Disclosed is a system and method to improve the extraction of transistor and OLED parameters in an AMOLED display for compensation of programming voltages to improve image quality. A pixel circuit includes an organic light emitting device, a drive device to provide a programmable drive current to the light emitting device, a programming input to provide the programming signal, and a storage device to store the programming signal. A charge-pump amplifier has a current input and a voltage output. The charge-pump amplifier includes an operational amplifier in negative feedback configuration. The feedback is provided by a capacitor connected between the output and the inverting input of the operational amplifier. A common-mode voltage source drives the non-inverting input of the operational amplifier. An electronic switch is coupled across the capacitor to reset the capacitor. A switch module including the input is coupled to the output of the pixel circuit and an output is coupled to the input of the charge-pump amplifier. The switch module includes a set of electronic switches that may be controlled by external control signals to steer current in and out of the pixel circuit and provide a discharge path between the pixel circuit and the charge-pump amplifier and isolating the charge-pump amplifier from the pixel circuit. A controller is coupled to the pixel circuit, charge-pump amplifier and the switch module. The controller controls input signals to the pixel circuit, charge-pump amplifier and switch module in a predetermined sequence to produce an output voltage value which is a function of a parameter of the pixel circuit. The sequence includes providing a program voltage to the programming input to either pre-charge an internal capacitance of the pixel circuit to a charge level and transfer the charge to the charge-pump amplifier via the switch module to generate the output voltage value or provide a current from the pixel circuit to the charge-pump amplifier via the switch module to produce the output voltage value by integration over a certain period of time.

A system is provided for controlling an array of pixels in a display in which each pixel includes a light-emitting device and a reference voltage source that controllably supplies a reference voltage having a magnitude that turns off the light-emitting device. While the reference voltage is coupled to a drive transistor, a control voltage is supplied to the gate of the drive transistor to cause the drive transistor to transfer to a node common to the drive transistor and the light-emitting device, a voltage that is a function of the threshold voltage and mobility of the drive transistor. During an emission cycle, the current conveyed through the light emitting device via the drive transistor is controlled by a voltage stored in the storage capacitor, which is a function of the threshold voltage and mobility of the drive transistor so that the current supplied to the light-emitting device remains stable.

An electronic device includes a display panel. The display panel includes a number of pixels, each of which includes a driving thin-film-transistor (TFT) and a light-emitting diode. Compensation circuitry external to the display panel applies offset data to pixel data for each pixel of the plurality of pixels before the pixel data is provided to the plurality of pixels.

A gamma measurement method of a display device includes: storing a current value that is measured during gamma tuning of a display panel; resetting a target current of global current management (GCM) by referring to the current value; and measuring gamma of the display panel while applying the target current of the GCM.

The present application discloses an organic light-emitting display panel and a driving method thereof, as well as an organic light-emitting display device. The display panel includes: an array arrangement including pixel units, wherein each pixel unit comprises a first, a second, a third and a fourth subpixels; a pixel circuit is formed in each subpixel; the first, second, third and fourth subpixels of an identical pixel unit are arranged along a column direction and are electrically connected with a given reference signal line; a color of the first subpixel, a color of the second subpixel, a color of the third subpixel and a color of the fourth subpixel differ from one another, and the color of the first subpixel, the color the second subpixel and the color the third subpixel are red, blue and green, respectively; and the color of the fourth subpixel is not white.

Methods and apparatuses relating to controlling an emission of a display panel. In one embodiment, a display driver hardware circuit includes row selection logic to select a number of rows in an emission group of a display panel, wherein the number of rows is adjustable from a single row to a full panel of the display panel, column selection logic to select a number of columns in the emission group of the display panel, wherein the number of columns is adjustable from a single column to the full panel of the display panel, and emission logic to select a number of pulses per data frame to be displayed, wherein the number of pulses per data frame is adjustable from one to a plurality and a pulse length is adjustable from a continuous duty cycle to a non-continuous duty cycle.

A display pixel is provided that is operable to support hybrid compensation scheme having both in-pixel threshold voltage canceling and external threshold voltage compensation. The display may include multiple p-type silicon transistors with at least one n-type semiconducting-oxide transistor and one storage capacitor. An on-bias stress phase may be performed prior to a threshold voltage sampling and data programming phase to mitigate hysteresis and improve first frame response. In low refresh rate displays, a first additional on-bias stress operation can be performed separate from the threshold voltage sampling and data programming phase during a refresh frame and a second additional on-bias stress operation can be performed during a vertical blanking frame. The display pixel may be configured to receive an initialization voltage and an anode reset voltage, either of which can be dynamically tuned to match the stress of the first and second additional on-bias stress operations to minimize flicker.