Rod-Shaped Additive for Liquid-Crystal Vertical Alignment
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Solution Overview
Problem
Conventional liquid-crystal display devices face challenges with uneven alignment and low voltage holding ratios due to the instability of polar compounds used for vertical alignment, leading to poor product yield and performance.
Innovation Solution
The introduction of a specific additive molecule with a rod-shaped structure, represented by formula (I), which improves vertical alignment, voltage holding ratio, and stability of liquid-crystal molecules without the need for a conventional alignment film, by forming a network structure that enhances molecular alignment and anchoring on substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional rubbing method is used to form alignment groove, then liquid-crystal alignment can be achieved, but uneven alignment and brush marks occur leading to poor product yield
Solution Approach 1:
The patent extracts and eliminates the rubbing step from the conventional alignment process. By using a photopolymerizable alignment layer that can be directly photo-patterned without mechanical rubbing, the invention removes the source of brush marks and uneven alignment, thereby improving both alignment uniformity and product yield
Solution Approach 2:
The patent replaces the mechanical rubbing method with a photochemical method. Instead of using mechanical contact to create alignment grooves, the invention uses photopolymerization of a specially designed alignment layer that self-organizes into alignment structures when exposed to light, eliminating mechanical defects
2Ease of manufacture
If polar compounds are used for vertical alignment without alignment layer, then the procedure is simplified, but compatibility with vertical alignment ability and high voltage holding ratio is difficult to achieve
Solution Approach 1:
The patent creates a composite liquid-crystal composition that combines polar compounds with specific additives having rod-shaped structures. This composite formulation integrates the vertical alignment capability of polar compounds with the voltage holding ratio enhancement provided by the rod-shaped additives, achieving both process simplification and high reliability
Solution Approach 2:
The patent modifies the chemical composition parameters of the liquid-crystal mixture by introducing specific rod-shaped additives with particular molecular structures. These parameter changes in composition enable the system to simultaneously achieve vertical alignment and maintain high voltage holding ratio without requiring additional alignment layers
3Manufacturing precision
If polar compounds are used for vertical alignment, then alignment ability is achieved, but stability of alignment ability needs to be improved
Solution Approach 1:
The patent formulates a composite liquid-crystal composition that combines polar compounds with rod-shaped additives. This composite structure provides enhanced stability to the alignment ability by creating a more robust molecular organization that resists degradation over time and under operating conditions
Solution Approach 2:
The patent incorporates stabilizing additives in advance into the liquid-crystal composition to prevent future degradation of alignment ability. These additives act as cushioning agents that maintain molecular order and prevent alignment deterioration before it occurs, ensuring long-term stability
Data Source
AI summary
An additive, liquid-crystal composition and a liquid-crystal display using the additive are provided. The additive includes a first additive molecule having a structure represented by formula (I):wherein Ri1, Ri2, Ri3, Ai1, Ai2, Zi, m1 and m2 are defined as in the specification.