Perforated Common Electrode for LCD Data Line Capacitance Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display (LCD) devices, particularly in fringe field switching (FFS) mode, face challenges with high capacitance on data lines leading to signal delay due to the overlap between the common electrode and data lines, which affects the efficiency and speed of data signal transmission.
Innovation Solution
The implementation of a common electrode with perforations along the data line regions, where each perforation has a width narrower than the data line, reduces the capacitance between the common electrode and the data line, thereby minimizing signal delay and enhancing the aperture ratio without causing light leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the common electrode is formed to overlap with the data line to improve electrical connection and coverage, then the capacitance between the common electrode and data line increases, but this causes signal delay and reduces data transmission efficiency
Solution Approach 1:
The common electrode is segmented by forming perforations (through-holes) along the data line region, dividing it into multiple isolated sections. This segmentation reduces the overlapping area between the common electrode and data line, thereby reducing capacitance and signal delay while maintaining electrical connection at the segmented points.
Solution Approach 2:
The common electrode is designed with a porous structure (perforations) in the region overlapping with the data line. This porous design reduces the effective overlapping area, reducing parasitic capacitance between the common electrode and data line, thus minimizing signal delay without completely eliminating the electrode's functional area.
2Loss of time
If the common electrode is formed with perforations to reduce capacitance and signal delay, then the overlap area between common electrode and data line decreases, but this may reduce the aperture ratio and light transmittance
Solution Approach 1:
The common electrode is designed with different local qualities: the region overlapping with the data line contains perforations to reduce capacitance, while other regions maintain continuous electrode structure for proper electrical function. This local differentiation allows the electrode to simultaneously achieve low capacitance in critical areas and maintain overall functionality.
Solution Approach 2:
The perforations in the common electrode are designed with specific dimensional characteristics (width smaller than data line width, controlled depth) to optimize the balance between reducing capacitance and maintaining light transmittance. The three-dimensional structure of the perforations allows precise control over the effective overlapping area.
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
This solution effectively reduces signal delay on data lines and prevents insufficient charging of capacitors in pixels, while maintaining high light transmittance and aperture ratio, by minimizing the overlap area between the common electrode and data lines through the use of perforations in the common electrode.
Implementation Method 1
Each of the perforations has a width smaller than a width of the data line. The plurality of perforations reduce capacitance between data line and the common electrode.
Data Source
AI summary
A pixel of an LCD device includes a gate line, a data line intersecting with the gate line, a gate insulation layer between the data line and the gate line, a thin film transistor formed at an intersection of the gate line and the data line, a planarization layer, a common electrode formed on the planarization layer, a pixel electrode formed over the common electrode, and an insulation layer between the common electrode and the pixel electrode. The common electrode is formed with groove extending along a region where the data line extends. Material of the common electrode is absent from the groove to reduce capacitance between the common electrode and the data line.