IPS LCD Electrode Sidewall Layout for Higher Aperture Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In-plane switching mode (IPS) active matrix liquid crystal display (LCD) devices face issues with reduced aperture ratio, deteriorated viewing angle characteristics, and inferior display characteristics due to rubbing dust caused by comb-teeth-shaped electrodes and differences in level within the aperture.
Innovation Solution
The IPS mode LCD device features pixel and common electrodes formed on the side walls of convex parts along data wirings, eliminating the need for comb-teeth-shaped electrodes, thereby increasing effective electrode areas, ensuring a uniform lateral electric field, and reducing rubbing dust production during the alignment process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If comb-teeth-shaped electrodes are formed in the aperture to reduce drive voltage, then electrode area is increased, but aperture ratio is lowered
Solution Approach 1:
The patent transitions from planar electrode arrangement to three-dimensional arrangement by forming electrodes on the side walls of convex portions. This vertical dimension utilization increases effective electrode area without occupying additional planar aperture space, thereby resolving the contradiction between electrode area and aperture ratio.
2Ease of manufacture
If comb-teeth-shaped electrodes are formed on the same plane, then manufacturing is simplified, but vertical electric field is generated causing deteriorated viewing angle characteristics
Solution Approach 1:
By forming electrodes on the side walls of convex portions rather than on the same plane, the patent creates a vertical separation between pixel electrodes and common electrodes. This three-dimensional arrangement generates primarily lateral electric fields parallel to the substrate, eliminating the harmful vertical electric field component and improving viewing angle characteristics.
3Area of moving object
If comb-teeth-shaped electrodes are formed in the aperture, then electrode coverage is improved, but difference in level causes rubbing dust production
Solution Approach 1:
The patent forms electrodes on the side walls of convex portions, creating a controlled three-dimensional structure. The alignment film covers both the upper surfaces and side walls, providing a continuous rubbing surface that eliminates abrupt level differences. This prevents rubbing dust generation while maintaining effective electrode coverage through the vertical side wall arrangement.
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 configuration enhances aperture ratio, improves viewing angle characteristics, and suppresses point defects by maintaining a uniform electric field and minimizing rubbing dust, resulting in improved brightness, contrast, and display quality.
Implementation Method 1
liquid crystal molecules of the liquid crystal layer within the pixel region are rotated in a plane approximately parallel to the substrate by a voltage applied between a common electrode connected to one the common electrode wirings and the pixel electrode
Data Source
AI summary
In a region where data wirings are formed on a TFT substrate, convex parts, each having a trapezoidal cross section or the like, are formed. A pixel electrode is formed on one of side faces of the convex part, and a common electrode is formed on the other side face. Furthermore, the pixel electrodes and the common electrodes are set to face each other between the convex parts adjacent to each other.