Pixel driving circuit and method of active organic electroluminescent display

Abstract

The invention discloses pixel driving circuit and method of an active organic electroluminescent display. The pixel driving circuit comprises a driving transistor, four switch transistors, a coupling capacitor, a storage capacitor and a light-emitting diode, wherein a drain electrode of the first transistor is connected with a data wire, a grid electrode of the first transistor is connected with a first scanning control wire, and a source electrode of the first transistor is connected with the C end of the coupling capacitor; a drain electrode of the second transistor is connected with source electrodes of the third transistor and the fourth transistor, a grid electrode of the second transistor is connected with the A ends of the coupling capacitor and the storage capacitor and a drain electrode of the third transistor, and a source electrode of the second transistor is connected with a drain electrode of the fifth transistor and the B end of the storage capacitor and is grounded through the organic light-emitting diode; a grid electrode of the third transistor is connected with a second scanning control wire; a drain electrode of the fourth transistor is connected with a power wire, and a grid electrode of the fourth transistor is connected with a light-emitting control wire; and a grid electrode of the fifth transistor is connected with the first scanning control wire, and a source electrode is grounded. The invention can effectively compensate the unevenness of threshold voltages of the transistors and the degradation of a start voltage of the OLED (Organic Light Emitting Diode), ensures that the brightness of an image displayed by the OLED is even and realizes high contrast.

Description

technical field [0001] The invention relates to a pixel driving technology of a light emitting diode display, in particular to a pixel driving circuit of an active organic electroluminescent display and a driving method thereof. Background technique [0002] Organic light-emitting diode (OLED) display has the advantages of small size, self-illumination, large viewing angle, short response time, and low production cost, which has attracted more and more researchers to participate. The passive driving method requires high efficiency and brightness of the OLED light-emitting device. The high-voltage or current pulse driving method makes the working efficiency of the light-emitting device very low and reduces the service life of the OLED, and cannot meet the requirements of high-resolution and large-information display. requirements. For large-screen high-resolution displays, active drive methods are usually used. [0003] Currently, thin film transistors used in active OLEDs ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the shortcoming and deficiency of above-mentioned prior art, provide the pixel driving circuit of active organic electroluminescent display, not only can effectively solve the inhomogeneity of each pixel point driving TFT threshold voltage in the active matrix OLED display, It can also solve the problem of OLED turn-on voltage degradation, so that the brightness of the OLED display is uniform

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