Gate Driving Circuit With Voltage Regulation Against Leakage Current
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Solution Overview
Problem
The existing gate driving circuits in liquid crystal displays (LCDs) face issues with leakage currents, which reduce the driving control voltage and impair the ability to generate gate signals of sufficient voltage for accurate data signal writing, thereby affecting image display quality.
Innovation Solution
The proposed gate driving circuit incorporates a voltage regulation unit, a control unit, and an energy store unit, along with a driving unit and a buffer unit, to regulate and maintain a high driving control voltage by using a second clock with a 180° phase shift relative to the first clock, preventing leakage current-induced voltage drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the transistor is turned on by the first clock for generating the gate signal, then the gate signal can be generated, but leakage current flows through the transistor causing the driving control voltage to decrease
Solution Approach 1:
The patent implements a feedback mechanism where the third transistor detects the voltage level of the driving control voltage and activates the fourth transistor to charge the capacitor when the voltage drops below a threshold, thereby restoring the voltage and eliminating the contradiction between gate signal generation and voltage maintenance
Solution Approach 2:
The circuit performs self-regulation through the voltage detection and automatic charging mechanism, where the system monitors its own voltage level and autonomously replenishes energy when needed, resolving the voltage loss issue without external intervention
2Power
If the energy store unit performs charging process based on start pulse signal, then the driving control voltage is generated, but leakage current causes voltage drop during operation
Solution Approach 1:
The patent employs periodic charging action through the fourth transistor that activates intermittently to replenish the capacitor when voltage drops occur, creating a periodic restoration cycle that maintains voltage stability despite continuous leakage current
Solution Approach 2:
The system dynamically adjusts the charging state of the capacitor based on the voltage level parameter, switching between discharge (during normal operation) and charge (when voltage drops), thereby adapting to changing conditions and maintaining reliable voltage output
3Duration of action of stationary object
If the driving control voltage decreases due to leakage current, then the transistor can remain on for continuous operation, but the gate signal cannot reach sufficient voltage for accurate data writing
Solution Approach 1:
The voltage detection mechanism provides feedback on the driving control voltage level, triggering automatic correction charging when the voltage falls below the threshold required for accurate data writing, thus maintaining both continuous operation and writing precision
Solution Approach 2:
The system takes preliminary action by charging the capacitor in advance when voltage drops are detected, preventing the voltage from falling to levels that would compromise data writing accuracy, thereby proactively maintaining operational precision
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
This solution ensures that the driving control voltage reaches and maintains a high enough level to generate gate signals effectively, enhancing image display quality by preventing unwanted voltage reductions due to leakage currents.
Implementation Method 1
The energy store unit, electrically coupled to the driving unit and the buffer unit, is put in use for providing the driving control voltage to the driving unit through performing a charging process based on the input signal
Implementation Method 2
The voltage regulation unit, electrically coupled to the energy store unit, is utilized for regulating the driving control voltage based on a control signal
Data Source
AI summary
A gate driving circuit having a low leakage current control mechanism is disclosed for providing a plurality of gate signals forwarded to a plurality of gate lines respectively. The gate driving circuit includes a plurality of shift registers. Each shift register includes a driving unit, an energy store unit, a buffer unit, a voltage regulation unit, and a control unit. The driving unit generates a gate signal based on a driving control voltage and a first clock. The buffer unit functions to receive a start pulse signal. The energy store unit provides the driving control voltage through performing a charging process based on the start pulse signal. The control unit generates a control signal based on the first clock and a second clock having a phase opposite to the first clock. The voltage regulation unit regulates the driving control voltage based on the control signal.