Scan Driving Circuit Pre-Charging for Display Panels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing frame rate of display panels results in shorter charging times for pixels, leading to insufficient charging, and the chamfering process in prior art reduces the pre-charge effect, affecting pixel charging efficiency.
Innovation Solution
A scan driving circuit with multiple output channels, multiplex modules, and a logical control unit that adjusts power signals based on scanning sequences, ensuring effective pre-charging by separating chamfering cycles between power signals to prevent clipping during the pre-charging phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the frame rate of the display panel is increased, then the display performance is improved, but the charging time of the pixel becomes shorter leading to insufficient charging
Solution Approach 1:
The patent applies pre-charging by activating the next row of pixels before the current row is fully scanned. The pre-charge signal is applied to the next row in advance, allowing capacitors to begin charging before the main scanning reaches that row. This preliminary action compensates for the reduced charging time caused by higher frame rates, ensuring sufficient charge accumulation without reducing the display refresh rate.
2Reliability
If the chamfering process is applied to reduce capacitive coupling effect, then the TFT switching performance is improved, but the pre-charge effect is reduced affecting pixel charging efficiency
Solution Approach 1:
The patent applies different signal characteristics to different operational phases: full chamfering is applied during the main scanning phase to reduce capacitive coupling effects and improve TFT switching reliability, while no chamfering (or reduced chamfering) is applied during the pre-charging phase to maintain charging efficiency. This local differentiation of signal quality allows each phase to optimize for its specific function without compromising the other.
Solution Approach 2:
The patent dynamically adjusts the chamfering characteristics of the power signal based on the operational phase. During pre-charging, the power signal maintains a simple waveform to maximize charging current. During main scanning, the power signal incorporates chamfering to reduce capacitive coupling. This dynamic adaptation of signal characteristics resolves the contradiction between switching performance and charging efficiency.
Data Source
AI summary
The invention provides a scan driving circuit, comprising: a plurality of rows of output channels successively arranged, at least a first multiplex module, and at least a second multiplex module; the power end of the (4m−3)-th row of output channels receiving a first power signal, the power end of the (4m−2)-th row of output channels receiving an output end of one first multiplex module, the power end of the (4m−1)-th row of output channels receiving an output end of one second multiplex module, and the power end of the 4m-th row of output channel receiving a second power signal; the first and second multiplex modules having control ends receiving a selection signal, a first input end receiving the first power signal, and a second input end receiving the second power signal; the selection signal controlling the first and second multiplex modules to change respective output power signal.