Pixel unit driving circuit and method as well as pixel unit

Abstract

The invention provides a pixel unit driving circuit and method as well as a pixel unit. The pixel unit driving circuit comprises a driving thin film transistor, a first switching element, a storage capacitor, a driving control unit and a charging control unit; a grid electrode of the driving thin film transistor is connected with the first end of the storage capacitor, and is further connected with a drain electrode of the driving thin film transistor through the charging control unit; a source electrode of the driving thin film transistor is connected with an OLED (Organic Light Emitting Diode), and is connected with the second end of the storage capacitor through the driving control unit; the drain electrode of the driving thin film transistor is connected with a driving power supply through the first switching element; the second end of the storage capacitor Cs is connected with the driving power supply through the charging control unit; the driving control unit is connected with the driving power supply and the OLED respectively; and the charging control unit is connected with a data wire and the OLED respectively. With the adoption of the pixel unit driving circuit provided by the invention, critical voltage of the driving thin film transistor is compensated, and the fall of driving current, caused by boosting of critical voltage due to material aging of the OLED, can be compensated.

Description

technical field [0001] The present invention relates to the field of organic light-emitting display, in particular to a pixel unit driving circuit, a pixel unit driving method and a pixel unit. Background technique [0002] The ability of AMOLED (Active Matrix Organic Light Emitting Diode) to emit light is driven by the current generated by the driving TFT in a saturated state, because when the same gray-scale voltage is input, different threshold voltages will produce different The drive current, resulting in current inconsistency. The uniformity of Vth (transistor threshold voltage) on the LTPS (low temperature polysilicon) process is very poor, and Vth also drifts, so the brightness uniformity of traditional 2T1C circuits has always been poor. [0003] The traditional 2T1C pixel unit driving circuit such as figure 1 As shown, the circuit only contains two TFTs, T1 is used as a switch, and DTFT is used for pixel driving. The operation of the traditional 2T1C pixel unit ...

AI Technical Summary

Problems solved by technology

The driving current formula of the 2T1C pixel unit driving circuit includes Vth. As mentioned above, due to the immaturity of the LTPS process, even with the same process parameters, the Vth of the TFTs at different positions on the manufactured panel is quite different, resulting in The driving current of OLED is different under the same grayscale voltage, so the brightness of different positions of the panel under this driving scheme will be different, and the brightness uniformity is poor.

At the same time, with the extension of the use of the OLED panel, the OLED material is gradually aging, resulting in an increase in the critical voltage of the OLED light emission. Under the same current, the luminous efficiency of the OLED material decreases, and the brightness of the panel decreases.

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