Pixel drive circuit of OLED display and drive method of said pixel drive circuit

Abstract

The invention discloses a pixel drive circuit of an OLED display and a drive method of said pixel drive circuit. The pixel drive circuit includes a drive transistor, two switch transistors, a coupling capacitor, a storage capacitor and an organic LED, wherein the drain electrode of the first switch transistor is connected with a data line, the grid electrode of the first switch transistor is connected with a first scanning control line and a source electrode of the first switch transistor is connected with a B terminal of the coupling capacitor; the drain electrode of the second switch transistor is connected with the storage capacitor and the A terminal of the coupling capacitor, the grid electrode of the second switch transistor is connected with the second scanning control line and the source electrode of the second switch transistor is connected with the drain electrode of the drive transistor, and the second switch transistor is connected with a power line through an OLED; the grid electrode of the drive transistor is connected with the storage capacitor and the A terminal of the coupling capacitor and the source electrode of the drive transistor is in grounded connection. According to the invention, the circuit can compensate non-uniformity of threshold voltage of a film transistor and the degradation of OLED threshold voltage effectively, so that uniformity of image luminance of an OLED display screen is improved.

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 a light emitting diode display and a driving method thereof. Background technique [0002] With the development of display technology, passive array OLED has been unable to meet the requirements of high resolution and large amount of information display. For large-screen high-resolution displays, active array drive methods are usually used. [0003] Currently, thin film transistors used in active array OLEDs mainly include hydrogenated amorphous silicon thin film transistors (a-Si:HTFT) and low temperature polysilicon thin film transistors (LTPS TFT). The threshold voltage of a-Si:H TFT will drift with the working time. In order to solve this problem, technicians once proposed a compensation circuit. The pixel driving circuit is composed of 6 a-Si:H transistors and a storage capacitor. Refer to Figure 1 and Figure 2, wher...

AI Technical Summary

Problems solved by technology

Generally speaking, the current-programmed pixel driving circuit needs a long charging time when displaying low grayscale, which affects its use in large-screen high-resolution displays.

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