Polysiloxane Alignment Film for LCD Residual Polymer Removal
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Solution Overview
Problem
The existing liquid crystal display devices, particularly in the Super Vertical Alignment (SVA) mode, face issues with residual non-hardened reactive mesogen in the liquid crystal layer, leading to persistence defects and reduced display quality, and require an alignment layer that uniformly aligns liquid crystal molecules.
Innovation Solution
A liquid crystal display device with a reduced residual polymer in the liquid crystal layer, utilizing an alignment film composed of first and second polysiloxanes with specific bonding structures and pre-tilting functional groups, and a phase separation enhancer, to uniformly align and tilt liquid crystal molecules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If reactive mesogen is used in the liquid crystal layer to pre-tilt liquid crystal molecules, then the alignment and viewing angle are improved, but non-hardened reactive mesogen remains in the liquid crystal layer causing persistence defects
Solution Approach 1:
The patent extracts the harmful non-hardened reactive mesogen from the liquid crystal layer by using an alignment film with specific polysiloxane structures that selectively interact with and remove residual reactive mesogen, thereby eliminating persistence defects while maintaining the alignment benefits
Solution Approach 2:
The alignment film acts as an intermediary between the liquid crystal layer and the substrate, containing polysiloxanes that mediate the interaction to reduce residual reactive mesogen. The first and second polysiloxanes work together to achieve both alignment and purification functions
2Shape
If a conventional alignment layer is used to align liquid crystal molecules, then alignment is achieved, but uniform alignment and persistence defect reduction are not sufficiently accomplished
Solution Approach 1:
The alignment film is constructed as a composite material containing first polysiloxanes and second polysiloxanes with different bonding structures. This composite structure enables both uniform alignment of liquid crystal molecules and effective reduction of persistence defects through the synergistic interaction of different polysiloxane components
Solution Approach 2:
The patent applies local quality by having different polysiloxane components perform different functions: first polysiloxanes provide alignment functionality while second polysiloxanes with specific bonding structures target the reduction of residual reactive mesogen, creating localized functional zones within the alignment film
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 effectively reduces residual polymers, enhancing display quality by minimizing persistence defects and improving the uniform alignment of liquid crystal molecules, thereby improving the viewing angle and overall performance of the liquid crystal display device.
Implementation Method 1
The reactive mesogen, if light is irradiated thereto, is hardened, pre-tilting the liquid crystal molecules.
Data Source
AI summary
A liquid crystal display device is provided, including a liquid crystal layer interposed between a first display panel and a second display panel; and an alignment film formed on at least one of the first and second display panels, the alignment film including first polysiloxanes and second polysiloxanes disposed on the first polysiloxanes, wherein a first portion of silicon atoms of the second polysiloxanes are bonded to vertical functional groups interacting with liquid crystal molecules in the liquid crystal layer, and to first pre-tilting functional groups aligning the liquid crystal molecules in the liquid crystal layer to be tilted with respect to at least one of the first and second display panels by being cross-linked. The bonding structure of the first and the second polysiloxanes being different.