Pixel unit driving circuit and method, pixel unit and display device

Abstract

The invention provides a pixel unit driving circuit, a pixel unit driving method, a pixel unit and a display device. The pixel unit driving circuit comprises a driving thin film transistor, a first switch element, a storage capacitor and a driving control unit, wherein the gate of the driving thin film transistor is connected with the first end of the storage capacitor and respectively connected with the drain of the driving thin film transistor and the low level output end of a driving power supply through the driving control unit; the second end of the storage capacitor is connected with the high level output end of the driving power supply; the source of the driving thin film transistor is connected with a negative electrode of an organic light emitting diode (OLED) through the first switch element and connected with a data wire through the driving control unit; and the drain of the driving thin film transistor is connected with the low level output end of the driving power supply through the driving control unit. The driving thin film transistor is guaranteed to work in a saturated region, and voltages of the gate and the source of the driving thin film transistor compensate for threshold voltage by controlling charging and discharging of the storage capacitor, so that the brightness of an OLED panel is uniform, and the problem of brightness attenuation is solved.

Description

technical field [0001] The invention relates to the field of organic light-emitting display, in particular to an AMOLED (active matrix organic light-emitting diode) pixel unit drive circuit and method, a pixel unit and a display device. Background technique [0002] Existing pixel unit drive circuits such as figure 1 As shown, the drive circuit includes two thin film transistors and a capacitor. One of the thin film transistors is a switch tube T1, which is controlled by the scanning signal Vscan output from the scanning line. The purpose is to control the input of the data signal Vdata on the data line. A thin film transistor is the driving tube T2, which controls the OLED to emit light; Cs is the storage capacitor, used to maintain the voltage applied to the driving tube T2 during the non-scanning period, and the above circuit is called a 2T1C pixel unit driving circuit. [0003] The ability of AMOLED (Active Matrix Organic Light Emitting Diode) to emit light is driven by...

AI Technical Summary

Problems solved by technology

[0003] The ability of AMOLED (Active Matrix Organic Light Emitting Diode) to emit light is driven by the current generated by the driving thin film transistor in a saturated state, because when the same gray scale voltage is input, the different driving thin film transistors The threshold voltage will lead to different drive currents, resulting in current inconsistencies

However, the uniformity of the threshold voltage Vth on the LTPS (low temperature polysilicon technology) process is very poor, and Vth also drifts, so the brightness uniformity of the traditional 2T1C pixel unit drive circuit has always been poor

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