Liquid Crystal Display Common Electrode Crosstalk Shielding
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Solution Overview
Problem
Liquid crystal display devices using the in-plane switching mode experience crosstalk due to overlapping electrodes, leading to reduced aperture ratio and transmittance, which affects display luminance and power consumption.
Innovation Solution
A liquid crystal display device design featuring a second common electrode that covers the data line, maintaining a constant common voltage and preventing crosstalk by overlapping with the data line in a specific pattern, thereby enhancing visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a common electrode with large area is formed for high aperture ratio in in-plane switching mode, then the aperture ratio is improved, but crosstalk occurs due to overlap with other electrodes and wirings
Solution Approach 1:
The common electrode is divided into two separate electrodes: a first common electrode formed below the data line and a second common electrode formed above the data line. This segmentation allows each electrode to be positioned strategically to prevent crosstalk while maintaining the overall aperture ratio. The first common electrode suppresses electric field noise from below the data line, while the second common electrode suppresses noise from above, eliminating vertical crosstalk without requiring a single large overlapping electrode.
2Manufacturing precision
If the data line width is increased, then the manufacturing precision is improved, but the aperture ratio and transmittance reduce
Solution Approach 1:
The solution moves the common electrode structure to a different dimensional arrangement by forming common electrodes on both the upper and lower sides of the data line. This vertical stacking in the Z-dimension allows the data line to maintain its necessary width for manufacturing precision while the common electrodes are positioned in the vertical dimension to suppress electric field noise, thereby preserving the aperture ratio and transmittance that would otherwise be reduced by wider data lines.
3Object-generated harmful factors
If a second transparent common electrode is formed above the data line to suppress electric field noise, then vertical crosstalk is eliminated, but the device complexity increases
Solution Approach 1:
The first common electrode below the data line and the second common electrode above the data line are electrically connected through a via hole that penetrates the data line. This merging of the two segmented electrodes into a single electrically continuous structure simplifies the overall device complexity by maintaining a unified common voltage potential, while still achieving vertical crosstalk elimination through the distributed electrode configuration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces light leakage and vertical crosstalk, increases the aperture ratio, and improves display visibility by maintaining a stable common voltage across the display device.
Implementation Method 1
a second common electrode which covers the data line... maintaining a constant common voltage and preventing crosstalk by overlapping with the data line
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A liquid crystal display device comprises additional common electrode patterns (160c, 160a) to shield data lines (132) and common lines (133) and, thus, to avoid undesired fringe fields. The liquid crystal display device prevents crosstalk and enhances visibility.