Gate Driver Circuit Feed-Through Voltage Compensation
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Solution Overview
Problem
Existing gate driver circuits for liquid crystal displays (LCDs) fail to effectively reduce the influence of feed-through voltage on image quality, which hampers the improvement of image quality due to variable liquid crystal capacitance.
Innovation Solution
A multi-stage gate driver circuit with an energy storage unit, charge unit, driver unit, first reset unit, and second reset unit is introduced, utilizing multiple reset voltages to compensate for feed-through voltage, forming a four-order driver circuit that reduces the impact of parasitic capacitors on pixel electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If common voltage adjustment is used to compensate for feed through voltage, then image quality can be improved, but the effectiveness is limited because liquid crystal capacitance is not a fixed parameter
Solution Approach 1:
The gate driver circuit is divided into multiple stages (first stage, second stage, third stage, fourth stage) with each stage having dedicated reset units and energy storage units. This segmentation allows independent control and compensation at different stages, enabling effective feed-through voltage compensation without relying on common voltage adjustment alone
Solution Approach 2:
The energy storage units are pre-charged before the actual driving operation. The first and second reset units are activated in advance to prepare the circuit state, and the third reset unit is activated later to complete the compensation. This preliminary action ensures that the compensation mechanism is ready before feed-through voltage affects the pixel electrodes
2Device complexity
If traditional second-order driver GOA circuit (4T1C) is used, then device complexity is reduced, but it cannot effectively reduce the influence of feed through voltage on image quality
Solution Approach 1:
The circuit is segmented into multiple driving stages (first, second, third, fourth stages) with each stage containing specific functional units (driver units, reset units, energy storage units). This segmentation increases the circuit order from second-order to fourth-order, enabling effective feed-through voltage compensation while maintaining reasonable complexity through modular design
Solution Approach 2:
Energy storage units are introduced as intermediary elements between the driver transistors and the gate lines. These energy storage units temporarily store electrical energy and release it at appropriate times to compensate for feed-through voltage effects, acting as mediators that decouple the direct relationship between driver output and pixel electrode voltage
3Object-affected harmful factors
If gate driver voltage is adjusted to compensate for feed through voltage, then pixel electrode voltage changes can be reduced, but liquid crystal capacitance variability makes objective improvement difficult
Solution Approach 1:
The circuit uses feedback mechanisms where the output of later stages (third and fourth stages) is fed back to control the reset units of earlier stages. This feedback loop automatically adjusts the compensation amount based on the actual feed-through voltage effect, eliminating the need for manual common voltage adjustment and providing objective image quality improvement
Solution Approach 2:
The multi-stage circuit structure enables self-compensation of feed-through voltage. The circuit automatically generates the necessary compensation signals through its internal energy storage units and reset units without requiring external intervention or adjustment of common voltage, making the system self-sufficient in correcting image quality issues
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The four-order driver circuit effectively compensates for feed-through voltage without altering common voltage, thereby enhancing image quality by stabilizing pixel electrode voltages and improving display performance.
Implementation Method 1
an energy storage unit; a charge unit, electrically connected between an (N−1)th gate line and the energy storage unit, and used for pre-charging the energy storage unit according to the signal of the (N−1)th gate line to obtain a voltage
Data Source
AI summary
The present disclosure provides a gate driver circuit and a driving method. The circuit comprises multi-stage GOA circuits, an Nth stage GOA circuit of which comprises: a charge unit, electrically connected between an (N−1)th gate line and an energy storage unit, and used for pre-charging the energy storage unit according to the signal of the (N−1)th gate line to obtain a voltage; a driver unit used for pulling up the signal of the Nth gate line to a pull-up voltage according to the voltage and a clock pulse signal; a first reset unit used for resetting the signal of the Nth gate line to the first reset voltage or the third reset voltage according to the signal of an (N+1) gate line and the first reset voltage or the third reset voltage; and a second reset unit used for resetting the signal of the Nth gate line to the second reset voltage according to the signal of an (N+3) gate line and the second reset voltage. In the circuit of the present disclosure, two reset units are used to achieve four-order driving for the pixel units, thus effectively solving the influence of a feed through voltage on the pixel electrode and improving the quality effect of images.