Organic light-emitting pixel driving circuit and driving method thereof

Abstract

The application discloses an organic light-emitting pixel driving circuit and a driving method thereof. The organic light-emitting pixel driving circuit comprises a reset unit, a data signal input unit, a compensation unit, a storage unit, a driving unit and a light-emitting unit. The driving unit generates light emission current based on a data signal and provides light emission current to the light-emitting unit. The driving unit comprises a first driving transistor and a second driving transistor which are connected in series and have a common gate electrode. The first driving transistor is used for storing the data signal to the storage unit in the compensation phase. The first driving transistor and the second driving transistor are used for providing light emission current to a light-emitting diode in the light emission phase. According to the scheme, current of the compensation phase is relatively high so that the data signal is enabled to be rapidly stored to the storage unit.

Description

technical field [0001] The present disclosure generally relates to display technology, and in particular, relates to an organic light emitting pixel driving circuit and a driving method thereof. Background technique [0002] With the continuous development of display technology, the sizes and specifications of displays are changing with each passing day. For example, in order to meet the portability of electronic devices, the demand for smaller size display screens continues to increase. [0003] In addition, with the development of display technology, users have higher requirements on the display quality of the display screen. For example, users tend to prefer high PPI (PixelsperInch, pixels per inch) display to improve the accuracy and consistency of the display. The OLED (Organic Light-Emitting Diode, Organic Light-Emitting Diode) display is more and more widely used in various portable electronic devices because of its thinness, power saving and other characteristics. ...

AI Technical Summary

Problems solved by technology

When the charging current is small and the capacity of capacitor C1 is large, charge the N1 node to the specified potential (V data -|V th |) will take longer

On the other hand, as the resolution of the display panel becomes higher and higher, the duration of the compensation phase of each pixel becomes shorter and shorter, resulting in insufficient charging of the capacitor C1, and the potential of the N1 node at the end of the compensation phase cannot reach the expected potential ( i.e. V data -|V th |) problem

When the charging current is not enough to make the potential of the N1 node reach the predetermined potential during the compensation phase, in order to meet the demand for the potential of the N1 node, on the one hand, V can be increased data The voltage value of the N1 node is used to compensate the potential of the N1 node, but this will undoubtedly increase the power consumption of the entire display panel

[0008] On the other hand, if the channel width w of the driving transistor DT is increased to increase the width-to-length ratio w / l of the driving transistor DT to increase the magnitude of the charging current, it will undoubtedly increase the difficulty of the manufacturing process.

The reason is that in practice, the width w of the driving transistor DT is relatively small, and when each pixel area changes a small width w, in different pixel driving circuits, the change of the width w of the driving transistor may produce a large error, resulting in The w / l of the drive transistor DT in each pixel area has a significant difference, resulting in uneven brightness and dark display problems

In addition, if the width-to-length ratio w / l of the drive transistor DT is increased by reducing the channel length l of the drive transistor DT, it will also lead to a large error caused by the length change in each drive circuit, and also cause brightness and darkness to be different. average display problem

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