GOA circuit

Abstract

The invention provides a GOA circuit including m cascaded GOA units. The n-th GOA unit includes: an output control module, a forward and reverse scan control module, a node signal control circuit, a second pull-down circuit, a first pull-down circuit, and a pull-up circuit. The forward and reverse scan control module controls the GOA circuit to perform forward scanning or reverse scanning. The output control module controls the outputting of the n-th gate drive signal. The first pull-down circuit includes a seventh TFT. The second pull-down circuit includes a fifth TFT. The node signal controlcircuit controls the on-off state of the fifth TFT. The pull-up circuit includes an eighth TFT. After a liquid crystal display panel is powered off, a first global control signal is a low-level signal. The GOA circuit can eliminate a residual image appearing during the abnormal power-off of the liquid crystal display panel and improves user experience.

Description

technical field [0001] The invention relates to the field of display technology, in particular to a GOA circuit. Background technique [0002] At present, liquid crystal display devices have been widely used in various electronic products as display components of electronic equipment, and a GOA (Gate Driver On Array, GOA for short) circuit is an important part of the liquid crystal display device. The GOA circuit is a technology that uses the existing thin-film transistor liquid crystal display array manufacturing process to manufacture the gate line scanning drive signal circuit on the array substrate to realize the drive mode of progressive scanning of the gate. [0003] Display panels based on Low Temperature Polysilicon (LTPS) technology can be divided into NMOS type, PMOS type, and both NMOS and CMOS of PMOS type. Similarly, GOA circuits are divided into NMOS circuits, PMOS circuits and CMOS circuits. Compared with CMOS circuits, NMOS circuits save the PP (P doping, ...

AI Technical Summary

Problems solved by technology

In the case of abnormal power failure, if the GOA circuit cannot effectively realize the All Gate ON function (that is, set all the gate driving signals in the GOA circuit to an effective potential to scan the liquid crystal display device at the same time), the panel will have afterimages.

[0004] For example, taking forward sweep as an example, in figure 1 In the GOA circuit unit shown, when an abnormal power-off is triggered, if the n+1th clock signal connected to the thin film transistor NT3 is at a high potential at this time, then the forward scanning control signal and the n+1th clock signal The potential will be pulled down to a low potential synchronously, and at the same time, the high potential of the gate of the thin film transistor NT5 cannot be released, thereby causing the thin film transistor NT5 to remain on, and at this time the thin film transistor NT8 is also in the on state, the high potential signal VGH and the low potential signal VGL Superimposed together, the gate of the thin film transistor NT7 cannot be pulled down completely, causing the thin film transistor NT7 to pull down the potential of the gate driving signal G(n) output to the thin film transistor of the pixel unit, so that the gate driving signal G(n) is not enough to turn on In the thin film transistor of the pixel unit, the charge of the pixel electrode cannot be released in time, which will cause residual image in the effective display area when the power is abnormally cut off

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