Pixel Unit Pre-Charging Circuit for High Refresh Rate Displays
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Solution Overview
Problem
In high-resolution and high-refresh-rate TFT-LCD displays, the short charging time for pixel units results in a lower charging rate, significantly impacting display effects due to insufficient time for pixel unit charging.
Innovation Solution
The array substrate design includes first and second scanning lines for each row of pixel units, where the second scanning lines are pre-charged by control switches connected to the first scanning lines of the next row, allowing for simultaneous charging and pre-charging of adjacent rows through a timing control circuit and scan drive circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If resolution and refresh frequency are increased, then display quality and responsiveness are improved, but pixel unit charging time becomes insufficient
Solution Approach 1:
The patent applies preliminary action by introducing a pre-charging phase before the main charging phase. Specifically, a pre-charging transistor is activated before the main charging transistor to partially charge the pixel electrode in advance, ensuring that the pixel unit has sufficient voltage even when the total charging time is reduced due to higher refresh rates. This resolves the contradiction by performing part of the charging work beforehand.
Solution Approach 2:
The charging process is segmented into two distinct phases: pre-charging and main charging. The pre-charging transistor and main charging transistor operate at different times and provide different charging currents. This segmentation allows the system to optimize each phase independently, with pre-charging providing initial voltage and main charging completing the full charge, thereby accommodating higher refresh rates while maintaining adequate charging time.
2Manufacturing precision
If resolution is increased, then display quality is improved, but charging rate of pixel units decreases
Solution Approach 1:
The pre-charging transistor activates before the main charging transistor to establish an initial voltage level on the pixel electrode. This preliminary charging action reduces the charging burden on the main transistor, enabling faster overall charging rates even as resolution increases and pixel density rises.
Solution Approach 2:
The patent changes the charging parameters by introducing a two-stage charging process with different current levels. The pre-charging phase uses a higher current for a shorter duration to quickly establish initial voltage, while the main charging phase uses a controlled current to complete the charge. This parameter change enables the system to maintain high charging rates despite increased resolution requirements.
Data Source
AI summary
The present disclosure provides an array substrate and a display device. The array substrate includes a plurality of pixel units arranged in a matrix form. When one row of pixel units is charged through a second scanning line, a next row of pixel units is pre-charged through a first scanning line, so as to improve the charging efficiency of the pixel units.