Polyimide Alignment Solution for Liquid Crystal Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional liquid crystal display devices face issues with residual images due to incomplete separation of ionic electrons from the alignment layer when the voltage is interrupted, leading to suboptimal performance in terms of contrast ratio, voltage holding, and reliability.
Innovation Solution
A liquid crystal alignment solution utilizing specific polymers such as polyamide acid-polyamide acid, polyimide-polyamide acid, and polyimide-polyimide polymers with defined chemical structures, which are applied to form a stable alignment layer that reduces residual images and enhances pre-tilt angle stability, voltage holding ratio, and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional alignment layer materials (polyimide, PVA, PEO, PA) are used, then the alignment layer can be formed with chemical resistance and thermal stability, but residual images occur due to incomplete separation of ionic electrons when voltage is interrupted
Solution Approach 1:
The patent changes the chemical parameters of the alignment layer by introducing specific functional groups (sulfonic acid groups -SO3H, carboxylic acid groups -COOH, or phosphoric acid groups -PO3H2) with defined concentrations (0.1-10 mmol/g). This parameter modification enables the alignment layer to effectively separate ionic electrons while maintaining stability, thereby reducing residual images without sacrificing reliability.
Solution Approach 2:
The patent creates a composite alignment layer material by combining polyimide base structure with acid functional groups. The resulting composite material (polyimide containing -SO3H, -COOH, or -PO3H2 groups) integrates the chemical resistance and thermal stability of polyimide with the ionic electron separation capability of acid groups, simultaneously achieving high reliability and reduced residual images.
2Ease of manufacture
If polyimide is used as alignment layer material due to its chemical resistance and thermal stability, then the alignment layer can be formed easily with uniform orientation, but the ionic electrons are not completely separated when voltage is interrupted
Solution Approach 1:
The patent modifies the chemical composition parameters of polyimide by incorporating acid functional groups (-SO3H, -COOH, -PO3H2) at specific concentrations. This parameter change enhances the ionic electron separation capability while maintaining the ease of manufacture and uniform orientation properties of polyimide alignment layers.
3Manufacturing precision
If inorganic film deposition method is used to form alignment layer, then uniform orientation of liquid crystal molecules can be obtained, but the manufacturing process is complex and not economically viable
Solution Approach 1:
The patent replaces the complex mechanical inorganic film deposition process with a simpler chemical coating method. By incorporating acid functional groups into the polyimide alignment layer, the invention achieves uniform liquid crystal molecule orientation through chemical interaction rather than mechanical deposition, thereby simplifying the fabrication process while maintaining manufacturing precision.
Data Source
AI summary
A liquid crystal alignment solution is provided, including at least one polymer selected from the group consisting of a polyamide acid-polyamide acid polymer represented by formula (A), a polyimide-polyamide acid polymer represented by formula (B) and a polyimide-polyimide polymer represented by formula (C), as defined in the contexts.