Pixel circuit and driving method thereof, electroluminescent display panel and display device

Abstract

The invention discloses a pixel circuit and a driving method thereof, an electroluminescent display panel and a display device. The pixel circuit comprises an initialization module, a data writing-in module, a light emitting control module, a voltage storage module, a driving transistor, a first voltage maintaining module, a switch control module, an external compensation module and a light-emitting diode. The driving transistor is a double-gate transistor; and a second gate of the double-gate transistor is electrically connected with the external compensation module through the switch control module. Under the control of the switch control module, the external compensation module collects the voltage of a third node and then provides a compensation voltage for a second node so as to realize adjustment of the threshold voltage of the dual-gate transistor, so that the threshold voltage of the dual-gate transistor is close to a standard threshold voltage and the current of the light-emitting diode during light emitting is be independent of the threshold voltage. Therefore, a phenomenon that the current is affected by the drift of the threshold voltage is avoided; and the residual image is eliminated to improve the quality of the displayed picture.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a pixel circuit, a driving method thereof, an electroluminescence display panel and a display device. Background technique [0002] Organic Light Emitting Display (OLED) display is a current-driven display, so it needs a stable current to drive it to emit light; and due to the process and device aging, the threshold voltage of the drive transistor in the pixel circuit (V th ) is prone to drift, resulting in uneven display and afterimages. [0003] At present, in order to avoid the drift of the threshold voltage, there are generally two ways: one is to use the pixel circuit with internal compensation to compensate the threshold voltage of the driving transistor, and the other is to use an external compensation circuit to compensate the threshold voltage of the driving transistor in the pixel circuit. , to alleviate the problems of display unevenness and image retention. [000...

AI Technical Summary

Problems solved by technology

[0006] The embodiment of the present invention provides a pixel circuit, its driving method, an electroluminescence display panel and a display device, so as to solve the problems in the prior art of how to effectively improve the drift of the threshold voltage, eliminate afterimages, and improve the uniformity of the display screen

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