Pixel Structure with Asymmetric Coupling Capacitors for LCD Greenish Frame Correction
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Solution Overview
Problem
Liquid crystal display panels using the dot inversion driving method often display greenish frames due to unbalanced polarity, leading to reduced gray scale and display quality issues.
Innovation Solution
The solution involves a pixel structure with specific coupling capacitors between data lines and common lines, adjusting the capacitance to ensure that red, green, and blue sub-pixels have identical pixel voltages, thereby balancing polarity and eliminating the greenish frame issue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the dot inversion driving method is used, then the liquid crystal display panel can be driven with polarity inversion to prevent permanent deformation, but the common voltage shifts toward high-level causing unbalanced polarity and greenish frame display
Solution Approach 1:
The patent applies different coupling capacitor values to different data lines based on their specific polarity patterns. The third and fifth data lines (controlling green sub-pixels) have smaller coupling capacitors compared to the second and fourth data lines, creating local差异化 compensation that balances the common voltage shift and eliminates greenish frame while maintaining the dot inversion driving benefits
Solution Approach 2:
The patent changes the capacitance parameter of coupling capacitors connected to different data lines. By adjusting the coupling capacitor values (making C3 and C5 smaller than C2 and C4), the patent compensates for the common voltage shift caused by unbalanced polarity distribution, thereby resolving the greenish frame issue while preserving the polarity inversion driving method's effectiveness in preventing permanent deformation
Data Source
AI summary
A pixel structure includes a plurality of data lines and a common line. The common line overlaps each data line, and is coupled with each data line to respectively form a first coupling capacitor, a second coupling capacitor, a third coupling capacitor, a fourth coupling capacitor, a fifth coupling capacitor, and a sixth coupling capacitor. The third coupling capacitor is smaller than the second coupling capacitor, and the fifth coupling capacitor is smaller than the fourth coupling capacitor.