Gate Driving Circuit Leakage Current Reduction
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Solution Overview
Problem
Existing touchscreen display devices face issues with leakage current during touch operations, leading to voltage drops and abnormal signal outputs, which affect display quality and touch recognition accuracy, especially in bright environments.
Innovation Solution
A gate driving circuit that time-divides the frame into display and touch periods, using a touch enable signal to manage the voltage of the Q node, ensuring it remains stable and minimizing leakage current by applying a gate signal to turn off the transistor and maintaining a voltage equal to the Q node during touch periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gate driver circuit operates during touch period without voltage management, then touch operation can be performed, but leakage current increases causing Q node voltage drop and abnormal signal output
Solution Approach 1:
The patent applies preliminary action by pre-charging the Q node to a high voltage level (VGH) before the touch period begins. The touch enable signal is activated early to ensure the Q node is fully charged and ready to withstand the touch period, preventing voltage drop during touch operation. This preparatory charging action ensures that when the touch period starts, the Q node has sufficient voltage headroom to maintain stable signal output despite leakage current.
Solution Approach 2:
The patent implements dynamics by dynamically adjusting the voltage level of the Q node based on the operational phase. During the touch period, the Q node voltage is maintained at a high level through the touch enable signal, while during non-touch periods it operates at normal levels. This dynamic voltage adjustment allows the circuit to adapt to different operational requirements, minimizing leakage current during touch operation while maintaining normal functionality during display periods.
2Adaptability or versatility
If the frame time is divided into display and touch periods, then touch recognition can be performed, but the clock time for high-resolution timing is reduced
Solution Approach 1:
The patent applies periodic action by dividing the frame time into distinct display periods and touch periods, with the touch period occurring at regular intervals. The touch enable signal is activated periodically to indicate when touch operation should occur, allowing the system to alternate between display and touch recognition modes. This periodic division enables touch recognition capability while maintaining a predictable timing structure that preserves sufficient clock time for high-resolution timing requirements.
3Loss of energy
If the Q node voltage is allowed to drop during touch period, then leakage current is reduced, but abnormal signal output occurs affecting display quality
Solution Approach 1:
The patent applies preliminary action by pre-charging the Q node to a high voltage level (VGH) before the touch period begins. The touch enable signal is activated early to ensure the Q node is fully charged and ready to withstand the touch period, preventing voltage drop during touch operation. This preparatory charging action ensures that when the touch period starts, the Q node has sufficient voltage headroom to maintain stable signal output despite leakage current.
Solution Approach 2:
The patent converts the harmful effect of leakage current during touch operation into a beneficial outcome by using the touch enable signal to actively maintain the Q node voltage. Instead of allowing the voltage to drop (which would reduce leakage but cause signal abnormalities), the system uses the touch enable signal to counteract the leakage current's effect, transforming the potential harm into an opportunity to demonstrate robust voltage management and stable signal output during touch operation.
Data Source
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AI summary
A display device and a device and method for driving the same are provided. The display device minimizes leakage of a stage in a standby state to hold a voltage of a Q node of the stage during touch operation.