Liquid Crystal Alignment Lamination to Prevent Orientation Irregularities
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Solution Overview
Problem
Light modulation devices with a liquid crystal alignment film on one substrate and a pressure-sensitive adhesive layer on the other experience orientation irregularities due to surface damage and shear force during manufacturing, leading to abnormal liquid crystal alignment.
Innovation Solution
A manufacturing method for light modulation devices with a liquid crystal alignment film on one substrate and a pressure-sensitive adhesive layer on the other, incorporating precise control of orientation angles within ±15 degrees to improve the orientation state, using silicone-based pressure-sensitive adhesives and alignment films to enhance lamination force and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a pressure-sensitive adhesive layer is formed on one substrate instead of an alignment film, then the device structure is simplified and manufacturing cost is reduced, but surface damage and shear force cause liquid crystal alignment abnormalities
Solution Approach 1:
The patent introduces a release film as an intermediary layer between the pressure-sensitive adhesive layer and the liquid crystal alignment film. This release film protects the alignment film from surface damage during lamination and prevents shear force from causing alignment abnormalities, while still allowing the adhesive to bond the substrates effectively.
Solution Approach 2:
The release film is applied to the pressure-sensitive adhesive layer before lamination with the alignment film. This preliminary protective action prevents surface damage and shear force from affecting the alignment film during the manufacturing process, ensuring proper liquid crystal alignment is maintained.
2Ease of manufacture
If a liquid crystal alignment film is formed only on one substrate, then the manufacturing process is simplified compared to forming alignment films on both substrates, but orientation irregularities occur due to surface damage and shear force
Solution Approach 1:
The release film serves as a protective intermediary that allows the alignment film to be formed on only one substrate while preventing surface damage and shear force from causing orientation irregularities during the lamination process.
Solution Approach 2:
The patent changes the surface energy parameters of the release film to optimize its protective function. By controlling the surface energy of the release film within specific ranges, it provides adequate protection to the alignment film while maintaining proper adhesion characteristics for the pressure-sensitive adhesive layer.
3Strength
If the surface energy of the pressure-sensitive adhesive layer is increased to improve adhesion, then lamination force is enhanced, but shear force increases causing alignment abnormalities
Solution Approach 1:
The release film acts as a buffer that decouples the adhesion function from the alignment function. This allows the pressure-sensitive adhesive layer to have high surface energy for strong adhesion without directly transmitting shear force to the alignment film, as the release film protects against this shear force.
Solution Approach 2:
The patent optimizes the surface energy parameters of both the release film and pressure-sensitive adhesive layer to achieve the right balance. The release film has surface energy characteristics that provide protection while the adhesive layer has surface energy within specific ranges to ensure adequate adhesion without excessive shear force transmission.
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 method stabilizes the orientation state of liquid crystals, reducing irregularities and enhancing the performance of light modulation devices by ensuring consistent alignment and adhesion between the two surfaces.
Implementation Method 1
a pressure-sensitive adhesive layer or adhesive layer is formed on the other substrate instead of the alignment film
Implementation Method 2
it is possible to obtain the orientation state of the liquid crystal compound suitable for uses in smart window or eyewear by the surface action of the alignment film and the pressure-sensitive adhesive layer or adhesive layer
Data Source
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AI summary
The present application can provide a method for manufacturing a light modulation device capable of removing defects such as orientation irregularities and further improving the orientation state in a light modulation device that adjusts orientation of a liquid crystal compound or the like with a liquid crystal alignment film and a pressure-sensitive adhesive layer or adhesive layer.