Pixel driving circuit and method for organic light emitting diode

Abstract

The invention provides a pixel driving circuit and method for an organic light emitting diode. The pixel driving circuit comprises a first transistor (T1), a second transistor (T2), a third transistor (T3), a fourth transistor (T4), a fifth transistor (T5), a sixth transistor (T6), a storage capacitor (C1) and the organic light emitting diode (OLED), and further comprises a scanning control end (Scan), a data signal end (Data), a constant flow source (Iref), a control light emitting signal end (Em), a power supply voltage (VDD) and a power supply negative electrode (VSS). The first transistor (T1) is a driving transistor. According to the pixel driving circuit and method for the organic light emitting diode, a 6T1C compensating circuit is adopted for carrying out compensation on a threshold voltage (Vth) of the driving transistor in each pixel, the threshold voltage (Vth) is captured through the constant flow source (Iref), data writing in and threshold voltage (Vth) capturing are carried out at the same time, the changes of the threshold voltage (Vth) of the driving transistor are effectively compensated for, and the display quality is improved.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a pixel driving circuit and a driving method of an organic light emitting diode. Background technique [0002] As a new generation of display technology, AMOLED (Active Matrix / Organic Light Emitting Diode, active matrix organic light emitting diode panel) has the advantages of high brightness, wide color gamut, wide viewing angle, fast response, and small size. The light-emitting device of the AMOLED is an organic light-emitting diode (Organic Light-Emitting Diode, OLED). Driven by the AMOLED driving circuit, when a current flows through the organic light-emitting diode, the organic light-emitting diode emits light. AMOLED is a current-driven device. The brightness is determined by the current flowing through the organic light-emitting diode itself. Most existing integrated circuits (Integrated Circuit, IC) only transmit voltage signals, so the AMOLED pixel circuit needs to comp...

AI Technical Summary

Problems solved by technology

Since the threshold voltage of the driving transistor (T2') will drift with the working time, the light emission of the organic light-emitting diode (OLED') will be unstable; in addition, due to the existence of the leakage current of the switching transistor (T1'), the storage capacitor The voltage of (C1') is unstable, which also leads to the instability of the light emission of the organic light-emitting diode (OLED')

Moreover, due to the drift of the threshold voltage of the driving transistor (T2') of each pixel is different, increasing or decreasing, the light emission among each pixel is uneven

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