Black frame voltage compensation method for data driver of OLED display

Abstract

The invention discloses a black frame voltage compensation method for a data driver of an OLED display, and the method comprises the following steps: giving out a plurality of set point voltages which at least comprise a highest-order voltage, a lowest-order voltage, and at least one-order voltage between the highest-order voltage and the lowest-order voltage; building a voltage curve of a data driver based on the set point voltages; enabling the highest-order voltage to be set independent of the voltage curve; and independently pulling up the highest-order voltage. Through the independent giving of a black frame voltage, the method enables the black frame voltage to be independent for adjustment, thereby enlarging range of circuit operation and exerting no impact on the setting of gray scale voltages. Through the setting of the independent black frame voltage, the method can increase the difference between the black frame voltage and the voltage of one gray scale which is one gray scale less, improves the tolerance for current leakage of a thin film transistor (TFT) assembly, and can solve a problem that the current leakage of the assembly causes the slight lighting of the frame which affects comparison.

Description

technical field [0001] The invention relates to the field of OLED displays, in particular to a method for compensating black screen voltage of a data driver of an OLED display. Background technique [0002] Currently, the OLED display mainly includes a timing controller, a data driver, a scan driver, and an emission control line driver. The voltage (Gamma) setting of the data driver is generally set in the same way as that of the LCD, which means that the data voltage of the black screen and the next-order data voltage are only about 10mV apart, as long as the voltage of the storage capacitor of the pixel drops due to leakage When it is easy to cause the panel to emit light and affect the brightness of the black screen, thereby reducing the contrast. [0003] figure 1 It is a schematic diagram of 2T1C pixel design for current OLED display products, figure 2 is the voltage curve of its data driver, image 3 is a schematic circuit diagram of the data driver, and the volta...

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Problems solved by technology

However, this method cannot independently increase the 255-level voltage of the black screen, because the second-order 245-level voltage will also be pulled up, which will affect the screen display

However, the gap between the 255-level voltage of the black screen and the next-order 254-level voltage is very small. When the voltage of the 255-level data driver (data) of the black screen is stored in the storage capacitor 21, the thin film transistor (TFT) 22 of the scanning line driver (scandriver) will be is turned off, but the voltage of the storage capacitor 21 will cause the voltage drop of the storage capacitor 21 through the leakage current of the thin film transistor (TFT) 22 of the scan driver (scandriver), and the voltage drop of the storage capacitor 21 will cause the thin film transistor (DTFT) of the data driver to drop ) 23 of the Vgs voltage (Vgs is the voltage between the gate and source of the MOS transistor) rises so that the thin-film transistor (DTFT) 23 of the data driver that should be in the off state is gradually turned on, thus generating an I OLED The electric current makes the organic light emitting diode (OLED) 24 panel emit light, thereby reducing the image display quality and contrast of the organic light emitting diode (OLED) 24 panel

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