Gate Driver Circuit With Q-Node Discharge for Low-Speed Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices face issues with the rise of Q node voltage during low-speed operation, causing image quality defects due to leakage and noise, leading to image quality defects.
Innovation Solution
A gate driver circuit with potential maintaining means connected to the Q node, maintaining the Q node voltage below a predefined level, preventing image quality defects by compensating for leakage and noise during low-speed operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the display panel operates at low-speed for a long time, then the Q node voltage rises during skip frame, but the output voltage at output node is damaged due to leakage and noise causing image quality defect
Solution Approach 1:
The patent applies preliminary anti-action by introducing a discharge transistor that actively discharges the Q node voltage before leakage and noise can cause damage. The discharge transistor is configured to maintain the Q node voltage below a predetermined level during skip frames, preventing the voltage rise that would otherwise lead to output voltage damage and image quality defects.
Solution Approach 2:
The discharge transistor serves as an intermediary element between the Q node and ground, providing a controlled discharge path. This intermediary component regulates the Q node voltage by selectively conducting discharge current, thereby preventing excessive voltage accumulation while maintaining normal operation during active frames.
2Reliability
If potential maintaining means is added to maintain Q node voltage, then image quality defect is prevented, but device complexity increases
Solution Approach 1:
The patent merges the discharge function with the existing shift register stage circuitry by integrating the discharge transistor into the conventional GIP circuit structure. The discharge transistor shares control signals and circuit nodes with existing components, combining voltage maintenance functionality with the standard shift register operation without requiring entirely separate control logic.
Solution Approach 2:
The discharge transistor is designed to perform multiple functions: it acts as a voltage clamp during skip frames to prevent Q node voltage rise, serves as part of the shift register stage during normal operation, and can be controlled using existing control signals from the gate driver circuit. This multi-functionality reduces the need for additional dedicated control mechanisms.
Data Source
AI summary
The disclosure relates to a display panel, a display device, and a gate driver circuit. According to an embodiment, a display panel includes a gate driver circuit in which when a display device operates at low-speed for a long time, a voltage of a Q node between an input and an output of a gate shift register in a gate driver circuit does not rise but is maintained at a value below a certain voltage. Here, potential maintaining circuit (PMC) is connected to a Q node, a Q2 node, or a vulnerable node between an input unit and an output unit of the gate shift register. The PMC maintains a potential of the Q node at a value below a selected level during a light-emitting operation for display. Thus, image quality defect due to damage to output voltage resulting from leakage and noise at an output node is prevented.