Liquid Crystal Display Alignment Aid for Pre-Tilt Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal displays face challenges in achieving uniform pre-tilt of liquid crystal molecules, leading to decreased contrast ratio and display deterioration due to non-uniform initial alignment, which results in afterimages.
Innovation Solution
Incorporating an alignment aid with halogen atoms and photo-polymerizable groups, such as mesogens like naphthalene or biphenyl, into the liquid crystal layer, which is electrically neutral or quasi-neutral, and polymerized using light to control pre-tilt and reduce non-polymerized alignment aid residues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional alignment methods are used, then the liquid crystal display can be manufactured, but non-uniform pre-tilt of liquid crystal molecules occurs leading to afterimages and decreased contrast ratio
Solution Approach 1:
The patent introduces an alignment aid as an intermediary substance between the liquid crystal molecules and the alignment layer. This alignment aid includes a mesogen having halogen atoms and a photo-polymerizable group, which mediates the alignment process by providing uniform pre-tilt control when polymerized, thereby eliminating afterimages and improving contrast ratio without compromising manufacturing feasibility
Solution Approach 2:
The patent changes the chemical parameters of the alignment system by using a specific alignment aid composition containing halogen atoms (such as bromine or chlorine) combined with photo-polymerizable groups. This parameter change enables the alignment aid to achieve both electrical neutrality and photo-polymerizability, resulting in uniform pre-tilt control and improved display characteristics
2Manufacturing precision
If an alignment aid with photo-polymerizable groups is used, then pre-tilt uniformity is improved, but non-polymerized alignment aid residues remain causing afterimages
Solution Approach 1:
The patent employs a photo-polymerization process that acts as a strong chemical reaction to completely polymerize the alignment aid molecules. The photo-polymerizable groups in the alignment aid undergo complete polymerization when exposed to light, converting all non-polymerized residues into polymerized structures, thereby eliminating the source of afterimages while maintaining pre-tilt uniformity
Solution Approach 2:
The patent converts the potential harm of non-polymerized alignment aid residues into a benefit by designing the alignment aid with specific photo-polymerizable groups that ensure complete polymerization. The halogen atoms in the mesogen enhance the polymerization efficiency, transforming the alignment aid from a potential source of afterimages into a beneficial component that provides both alignment and complete polymerization
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 ensures uniform pre-tilt control of liquid crystal molecules, reducing afterimages and improving display characteristics by minimizing the remaining non-polymerized alignment aid, thereby enhancing the overall performance of liquid crystal displays.
Implementation Method 1
The alignment polymer is formed by light-irradiating the liquid crystal molecules and an alignment aid
Data Source
AI summary
A liquid crystal display includes: a first substrate, a second substrate facing the first substrate, a field generating electrode disposed on at least one of the first substrate and the second substrate and a liquid crystal layer interposed between the first substrate and the second substrate. The liquid crystal layer includes liquid crystal molecules and an alignment polymer. The alignment polymer is formed by light-irradiating the liquid crystal molecules and an alignment aid. The alignment aid includes a mesogen having halogen atoms and at least one photo-polymerizable group combined to the mesogen, and the alignment aid is electrically neutral or quasi-neutral.