GOA Pull-Down Maintenance Module Reduces Leakage
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Solution Overview
Problem
Conventional gate driver on array (GOA) circuits using amorphous silicon TFTs experience current leakage due to zero gate-source voltage difference, affecting voltage levels and requiring additional signal lines, which increases production costs and complicates narrow border design.
Innovation Solution
The GOA circuit design incorporates a pull-up control module, output module, pull-down module, and maintenance modules with specific TFT configurations and signal controls to manage voltage levels without additional signal lines, ensuring negative gate-source voltage differences to reduce current leakage and enhance stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If zero gate-source voltage difference is used in amorphous silicon TFTs, then the TFT structure is simple, but current leakage occurs affecting voltage levels
Solution Approach 1:
The patent changes the gate-source voltage parameter from zero to negative voltage by introducing a maintenance module that applies a negative voltage to the gate of the pull-down maintenance TFT. This parameter change reduces the gate-source voltage difference magnitude, thereby reducing current leakage while maintaining circuit functionality without adding complex structures.
2Reliability
If additional signal lines are added to reduce current leakage, then voltage stability improves, but production cost increases and narrow border design becomes difficult
Solution Approach 1:
The patent makes the maintenance module's TFT serve multiple functions: it maintains the low voltage level at the first node during the scan signal output phase, and simultaneously reduces current leakage by applying negative gate voltage. This multi-functionality eliminates the need for separate additional signal lines while achieving both voltage stability and leakage reduction.
Solution Approach 2:
The maintenance module uses the existing scan signal and low voltage signal to automatically maintain the voltage level at the first node without requiring external control signals. The circuit self-regulates by using the scan signal timing to activate the maintenance TFT, which then holds the voltage stable throughout the output phase.
3Ease of manufacture
If conventional GOA circuit structure is used, then manufacturing process is simple, but current leakage affects performance
Solution Approach 1:
The patent segments the GOA circuit into distinct functional modules: pull-up control module, output module, pull-down module, and pull-down maintenance module. Each module has a specific function, and the maintenance module is integrated into the existing structure rather than adding a completely separate system. This segmentation allows for simpler manufacturing while improving performance through modular functionality.
Data Source
AI summary
The invention provides a GOA circuit, other than the first to the fourth GOA units, in each GOA unit: the first pull-down maintenance module receives the first control signal, low voltage signal, scan signal and circuit start signal, and is connected to the first node, wherein the 52nd TFT of the first pull-down maintenance module has a gate connected to the first node, a source receives the circuit start signal, and a drain connected to the gates of the 31st TFT and 41st TFT so that when the first node is at high voltage, the gate-source voltage difference of the 31st TFT and the 41st TFT are both negative to effectively reduce the current leakage and prevent the current leakage from affecting the voltage of the first node, to improve the circuit stability without additional signal lines, able to facilitate production cost reduction and achieving narrow border design.