Amoled pixel driving circuit and its driving method

Abstract

The present invention provides an AMOLED pixel driving circuit and its driving method, which adopts a 6T1C pixel driving circuit with a specific driving sequence, can effectively compensate the threshold voltage of the driving thin film transistor, and stabilize the current flowing through the organic light emitting diode , to ensure uniform luminance of organic light-emitting diodes, improve the display effect of the picture, and reduce the number of thin-film transistors and scanning control signals through the combination of N-type thin-film transistors and P-type thin-film transistors, thereby simplifying the structure of the pixel driving circuit and increasing the effective Luminous area.

Description

technical field [0001] The invention relates to the field of display technology, in particular to an AMOLED pixel driving circuit and a driving method thereof. Background technique [0002] Organic light emitting diode (Organic Light Emitting Display, OLED) display device has self-illumination, low driving voltage, high luminous efficiency, short response time, high definition and contrast, nearly 180° viewing angle, wide operating temperature range, and can realize flexible display and With many advantages such as large-area full-color display, it is recognized by the industry as a display device with the most potential for development. [0003] OLED display devices can be divided into passive matrix OLED (Passive Matrix OLED, PMOLED) and active matrix OLED (Active Matrix OLED, AMOLED) two categories according to the driving method, namely direct addressing and thin film transistor (Thin Film Transistor, TFT) matrix addressing two types. Among them, AMOLED has pixels arra...

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Problems solved by technology

[0005] like figure 1 As shown, an AMOLED pixel driving circuit with a 7T2C structure includes 7 thin film transistors and 2 capacitors, which are respectively: a first thin film transistor T10, a second thin film transistor T20, a third thin film transistor T30, a fourth thin film transistor T40, The fifth thin film transistor T50, the sixth thin film transistor T60, the seventh thin film transistor T70, the first capacitor C10, and the second capacitor C20, the pixel drive circuit needs to be controlled by four scan control signals, which are the first scan control signal S10, The second scan control signal S20, the third scan control signal S30, and the fourth scan control signal S40; the working timing diagram of the circuit is as follows figure 2 As shown, the working process of the circuit includes: a first stage 10, a second stage 20, and a third stage 30, wherein in the second stage 20, the second scanning control signal S20 first provides a high potential and then provides a low potential, and this When the second scanning control signal S20 provides a low potential, due to the effect of the first capacitor C1, the potential at the connection point between the first capacitor C1 and the second capacitor C2 will be unstable, and the pixel driving circuit needs 7 One thin film transistor and two capacitors, the structure is complex, the effective light-emitting area of ​​the pixel is low, and the number of scanning control signals is large, which makes the timing controller more complicated

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