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 source of the driving thin film transistor is connected with a data wire through the first switch element; the drain of the driving thin film transistor is respectively connected with a positive electrode of an organic light emitting diode (OLED) and the low level output end of a driving power supply; the source of the driving thin film transistor is connected with the high level output end of the driving power supply through the driving control unit; the gate of the driving thin film transistor is connected with the drain of the driving thin film transistor through the driving control unit; and the driving control unit controls the driving thin film transistor to work in a saturated region and voltages of the gate and the source of the driving thin film transistor to compensate for threshold voltage by controlling charging and discharging of the storage capacitor. By the invention, the problems of non-uniform brightness of an OLED panel and brightness attenuation are solved.

Description

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

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 transistor in a saturated state, because when the same grayscale voltage is input, the different threshold voltages of the driving transistor Will lead to different drive currents, resulting in inconsistencies in the current

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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