LCD Pixel Electrode Slits for Dark Line Suppression
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Solution Overview
Problem
In liquid crystal display devices with multiple domains, a dark line phenomenon occurs at the outline of pixels due to differing tilt directions of liquid crystal molecules, affecting display quality.
Innovation Solution
The liquid crystal display device incorporates a pixel electrode with a slit group along its outline and vicinity, featuring alignment films on both substrates with distinct alignment directions, which helps in suppressing the dark line formation by managing the tilt directions of liquid crystal molecules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple domains with different liquid crystal tilt directions are formed in one pixel to widen viewing angle, then viewing angle is improved, but dark lines appear at pixel outlines
Solution Approach 1:
The pixel electrode is segmented by introducing slit groups that divide it into multiple regions. These slits create distinct domains within the pixel, allowing different liquid crystal tilt directions in different regions, which widens the viewing angle while controlling dark line formation at the pixel outline
Solution Approach 2:
The slit groups are strategically positioned at specific locations (such as at oblique angles to the pixel outline) to create local variations in liquid crystal alignment. This local modification of the electrode structure controls the tilt direction in specific regions, improving viewing angle while suppressing dark lines at the pixel boundary
2Adaptability or versatility
If domain limitation means such as protrusions or fishbone electrodes are used to control liquid crystal tilt direction, then viewing angle is improved, but device structure becomes more complex
Solution Approach 1:
Instead of changing the physical structure of the electrode into complex shapes like fishbone patterns or protrusions, the invention changes the parameter of the electrode by introducing slits. This simpler modification achieves the same domain control function with less structural complexity and easier manufacturing
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 presence of a slit group on the pixel electrode effectively reduces the width of dark lines and improves transmittance, enhancing the display quality by minimizing the occurrence of dark lines at the pixel outlines.
Implementation Method 1
A first alignment film is disposed on a surface of the pixel electrode, the surface being a surface facing the liquid crystal layer. A second alignment film is disposed on a surface of the counter electrode, the surface being a surface facing the liquid crystal layer.
Implementation Method 2
The liquid crystal molecules are tilted in different directions in the domains in this way, thereby allowing improvement in a viewing angle.
Data Source
AI summary
A liquid crystal display device includes: a liquid crystal layer extending at least in a display region; first and second substrates affixed to each other so as to sandwich the liquid crystal layer therebetween; and a pair of polarization plates disposed to sandwich these substrates therebetween. The first substrate is provided with a pixel electrode corresponding to each of a plurality of pixels. The second substrate is provided with a counter electrode so as to face the pixel electrode. A first alignment film is disposed on the pixel electrode. A second alignment film is disposed on the counter electrode. The pixels each include a plurality of domains having different combinations of alignment directions of the first and second alignment films. The pixel electrode has a slit group along at least a part of an outline of the pixel electrode and in the vicinity of the outline.