Elliptical Electrode Opening for LCD Response Speed and Transmittance
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Solution Overview
Problem
Horizontal alignment mode liquid crystal display devices face challenges in achieving both high-speed response and high transmittance, particularly for ultra-high-definition pixels, as existing techniques either compromise transmittance or introduce image sticking issues.
Innovation Solution
The implementation of an opening with an elliptical or circular shape in the electrode generates a fringe electric field, allowing for controlled alignment of liquid crystal molecules without reducing transmittance, thereby enhancing response speed and maintaining high transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a polymer structure is formed by photopolymerizing a photopolymerizable monomer in the liquid crystal layer, then the response speed is improved, but the transmittance decreases due to reduced aperture ratio
Solution Approach 1:
The invention extracts the harmful polymer structure formation by removing photopolymerizable monomers from the liquid crystal composition. Instead of allowing polymerization that reduces aperture ratio and transmittance, the patent uses a different approach (surface treatment with specific compounds) to achieve fast response without the harmful polymer network that blocks light
Solution Approach 2:
The invention changes the parameter of the liquid crystal composition by specifying particular compounds for surface treatment (compounds with specific molecular structures and properties) rather than using photopolymerizable monomers. This parameter change allows achieving fast response speed through controlled molecular alignment without the side effect of reduced transmittance
2Speed
If rectangular or rhombic openings are formed in the common electrode to rotate liquid crystal molecules, then the response speed is improved, but the transmittance significantly decreases due to limited rotation region
Solution Approach 1:
The invention applies asymmetry by using openings with specific aspect ratios (width-to-length ratio of 0.5 to 2.0) and specific orientations relative to the liquid crystal alignment direction. This asymmetric opening design optimizes the fringe electric field distribution to achieve effective liquid crystal rotation with larger active area, improving both response speed and maintaining transmittance
Solution Approach 2:
The invention considers the dimensional relationship between the opening shape and the liquid crystal molecule rotation in three-dimensional space. By optimizing the opening's width-to-length ratio and orientation, the patent creates an optimal fringe field distribution that extends the effective rotation region, allowing more liquid crystal molecules to participate in the switching process
3Illumination intensity
If the aperture ratio is increased to improve transmittance, then the transmittance is improved, but the response speed decreases
Solution Approach 1:
The invention applies local quality by creating non-uniform electric field distribution through strategically positioned openings in the common electrode. The fringe electric field is concentrated at specific locations (edges and corners of openings) where it most effectively influences liquid crystal alignment, allowing fast response in critical regions while maintaining high transmittance overall through larger aperture ratio
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 approach enables a liquid crystal display device to achieve both high-speed response and high transmittance, particularly beneficial for ultra-high-definition pixels, by stabilizing liquid crystal molecule alignment and preventing excessive rotation.
Implementation Method 1
forming an opening having a shape including an elliptical portion and/or a circular portion in the electrode as an opening for generating a fringe electric field
Data Source
AI summary
A liquid crystal display device includes, in the given order: a first substrate; a liquid crystal layer containing liquid crystal molecules; and a second substrate; wherein the first substrate includes a first electrode, a second electrode positioned closer to the liquid crystal layer than the first electrode is, and an insulating film between the first electrode and the second electrode, the second electrode has an opening having a shape including an elliptical portion and/or a circular portion, in a no-voltage-applied state, where no voltage is applied between the first electrode and the second electrode, the liquid crystal molecules are aligned parallel to the first substrate, and in a plan view, the major axis of the elliptical portion is parallel or perpendicular to the alignment azimuth of the liquid crystal molecules in the no-voltage-applied state.