OLED driving film transistor parameter obtaining method

Abstract

The invention provides an OLED driving film transistor parameter obtaining method. The OLED driving film transistor parameter obtaining method comprises steps of using a data line to provide different first gate voltage, second gate voltage, third gate voltage and fourth gate voltage, using a sensing unit at a gate of a second film transistor to write the first gate voltage, the second gate voltage, the third gate voltage and the fourth gate voltage, wherein the source electrode of the second film transistor detects driving current flowing through a second film transistor and a third film transistor when a conducted third film transistor, a lead and a switched-off switch are connected to reference voltage, calculating a drain source electrode step voltage of a third film transistor according to current flowing through the second film transistor and the third film transistor and obtaining source electrode voltage of a more accurate second film transistor which corresponds to the first gate voltage, the second gate voltage, the third gate voltage and the fourth gate voltage so as to obtain accurate parameters of the driving film transistor. As a result, compensation is performed on an OLED panel according to the parameters of the driving film transistor in order to improve image compensation uniformity.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a parameter acquisition method for OLED driving thin film transistors. 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 pi...

AI Technical Summary

Problems solved by technology

It is generally considered that the gate-source voltage difference of the second thin film transistor T20 corresponding to the driving current is the difference between the preset gate voltage and the reference voltage Vref, but in fact, when the switch S10 is closed, due to the equivalent resistance of the wire 300 and The presence of the drain-source voltage across the third thin film transistor T30 makes the source voltage of the second thin film transistor T20 greater than the reference voltage Vref, that is, the gate-source voltage difference of the second thin film transistor T20 is not equal to the preset gate voltage The difference from the reference voltage Vref, so the parameters obtained to drive the thin film transistor will have a large deviation

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