Vertical Alignment Liquid Crystal Display Polymer Network
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Solution Overview
Problem
The existing Vertical Alignment (VA) liquid crystal display technology faces challenges with high energy consumption, environmental impact, and human health hazards due to the use of chemical solvents in the alignment process, and the alignment layer formation process is non-uniform and prone to defects, leading to poor long-term reliability and high production costs.
Innovation Solution
A VA liquid crystal display that eliminates the need for a Polyimide (PI) alignment layer by using an auxiliary alignment agent with a polymer network, where the agent is directly dissolved in the liquid crystal and aligns the molecules vertically without solvents, and a polymer network is formed through UV irradiation to enhance alignment force and anchoring energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a PI alignment layer is coated using chemical solvents and high-temperature baking is applied, then vertical alignment of liquid crystal molecules is achieved, but energy consumption increases and environmental harm occurs
Solution Approach 1:
The patent changes the physical and chemical parameters of the alignment process by replacing the traditional PI alignment layer with a small molecule auxiliary alignment agent that has different molecular structure and alignment mechanism. This agent contains polar groups that interact with liquid crystal molecules through dipole-dipole interactions, achieving vertical alignment without requiring high-temperature baking (200°C+) and chemical solvents like NMP, thus resolving the contradiction between alignment reliability and energy consumption
Solution Approach 2:
The patent utilizes the phase transition properties of the auxiliary alignment agent, which transitions from a liquid state (dissolved in liquid crystal) to a solid crystalline state upon cooling, forming a stable alignment structure. This phase transition enables the alignment function without requiring high-temperature processing, reducing energy consumption while maintaining alignment stability
2Reliability
If a PI alignment layer is coated using chemical solvents and high-temperature baking is applied, then vertical alignment of liquid crystal molecules is achieved, but environmental harm and health hazards increase
Solution Approach 1:
The patent extracts and eliminates the harmful components from the alignment process by removing the PI alignment layer formulation that contains NMP solvent and other harmful chemicals. The small molecule auxiliary alignment agent is designed to be solvent-free or use environmentally friendly solvents, and does not require high-temperature baking that releases harmful emissions, thus achieving vertical alignment without environmental harm and health hazards
Solution Approach 2:
The patent converts the previously harmful high-temperature baking process and chemical solvent usage into a beneficial low-temperature or room temperature process using the auxiliary alignment agent. The agent's molecular design allows it to self-assemble and provide alignment function through weak intermolecular forces, transforming the harmful alignment process into an environmentally friendly one while maintaining alignment reliability
3Reliability
If a PI alignment layer is coated, then vertical alignment process is completed, but alignment uniformity and coating quality are poor leading to yield loss
Solution Approach 1:
The patent implements self-service alignment mechanism where the small molecule auxiliary alignment agent automatically orients itself through molecular interactions with the liquid crystal molecules. The agent's polar groups spontaneously align with the liquid crystal molecules' long axes through dipole-dipole interactions, eliminating the need for complex coating equipment and high-temperature baking processes that cause non-uniformity, thus improving manufacturing precision while maintaining alignment stability
Solution Approach 2:
The patent replaces the mechanical coating system (spray coating equipment, high-temperature baking furnaces) with a molecular-level alignment mechanism. The auxiliary alignment agent works at the molecular level through chemical interactions rather than requiring complex mechanical coating processes, eliminating defects such as non-uniform coating, lack of coating, non-stick, and foreign matter, thereby improving yield and alignment uniformity
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 stabilizes the alignment of liquid crystal molecules, improves the vertical alignment effect, reduces energy consumption, and enhances environmental protection by eliminating the need for high-temperature baking and solvent use, while maintaining high contrast and wide view angle properties.
Implementation Method 1
a polymer network which penetrates the entire liquid crystal layer, stabilizes alignment of the liquid crystal molecules and enhances vertical alignment effect of the auxiliary alignment agent to the liquid crystal molecules
Implementation Method 2
a polymer network which penetrates the entire liquid crystal layer
Data Source
AI summary
A vertical alignment liquid crystal display includes a first substrate, a second substrate, a liquid crystal layer located between the first substrate and the second substrate, a first and a second passivation layers respectively located at inner sides of the first and the second substrates, a common electrode layer and a pixel electrode layer respectively located on the first and the second passivation layers. The liquid crystal layer includes liquid crystal molecules, auxiliary alignment agent and a polymer network penetrating the entire liquid crystal layer. The auxiliary alignment agent makes the liquid crystal molecules in the liquid crystal layer vertically aligned on the surfaces of the first and the second substrates. The polymer network stabilizes alignment of the liquid crystal molecules and enhances vertical alignment effect of the auxiliary alignment agent to the liquid crystal molecules.