Liquid Crystal Capsule Shell Surface Tension Reduction

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Solution Overview

Problem

Liquid crystal display devices with traditional liquid crystal layers face challenges due to high driving voltage requirements and complexity in measuring anchoring energy, which is exacerbated by the use of liquid crystal capsules with shells having a critical surface tension greater than or equal to that of the liquid crystal molecules, leading to increased anchoring energy and voltage needs.

Innovation Solution

A liquid crystal display device and method involving a liquid crystal capsule with a shell having a critical surface tension smaller than the liquid crystal molecule, where the shell is formed using a polymer material or an additive with a lower critical surface tension, reducing anchoring energy and driving voltage through a nano emulsion solution process and ultraviolet irradiation for polymerization and lamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a liquid crystal capsule with a shell having a critical surface tension greater than or equal to that of the liquid crystal molecule is used, then the shell provides sufficient structural stability, but the anchoring energy increases excessively leading to high driving voltage (over 150V)

Engineering Contradiction:

Improvestructural stability of shellVSAvoiddriving voltage

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the critical surface tension parameter of the shell material to be smaller than that of the liquid crystal molecule, which fundamentally alters the anchoring energy characteristics and reduces driving voltage from over 150V to below 60V while maintaining structural stability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite shell structure consisting of a polymer outer shell and an inner layer with lower critical surface tension, combining the structural advantages of the polymer shell with the low anchoring energy properties of the inner layer to simultaneously achieve stability and voltage reduction

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If the critical surface tension of the shell is reduced to lower anchoring energy and driving voltage, then the driving voltage decreases to below 60V, but the measurement and quantization of anchoring energy becomes more difficult

Engineering Contradiction:

Improvedriving voltageVSAvoidanchoring energy measurement

Core Design Contradiction:

Use of energy by moving objectVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces complex mechanical measurement methods with a material property-based approach, where the critical surface tension of the shell material is selected to be smaller than that of the liquid crystal molecule, thereby reducing anchoring energy and driving voltage while simplifying the measurement process through material selection rather than complex experimentation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a traditional liquid crystal layer with two glass substrates is used, then the device provides good color reproducibility, but the weight and thickness increase making it unsuitable for flexible displays

Engineering Contradiction:

Improvecolor reproducibilityVSAvoiddevice weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent extracts and removes one of the two glass substrates from the traditional LCD structure, replacing it with a flexible substrate, thereby eliminating the weight and thickness penalty while maintaining the liquid crystal layer and color reproducibility through the capsule-based liquid crystal configuration

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs flexible substrates and thin film structures to replace rigid glass substrates, enabling the LCD device to be flexible and lightweight while maintaining optical performance through the liquid crystal capsule layer

Inventive Principle:

Principle #30Flexible shells and thin films

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 approach reduces the driving voltage of the liquid crystal layer to below 60V, simplifies the fabrication process, and enables easier application of liquid crystal capsules in LCD devices by lowering anchoring energy and improving optical properties.

Implementation Method 1

a critical surface tension of the shell is smaller than a critical surface tension of the liquid crystal molecule

Methodology Applied

Scientific EffectSurface tension: Surface Tension

Implementation Method 2

the shell is formed using a polymer material or an additive with a lower critical surface tension, reducing anchoring energy and driving voltage through a nano emulsion solution process and ultraviolet irradiation for polymerization

Methodology Applied

Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentUS11619842B2Liquid crystal display device including liquid crystal capsule and method of fabricating the same

Publication Date: 2023.04.04 LG DISPLAY CO LTD

AI summary

A liquid crystal capsule includes: a shell; and a liquid crystal molecule in the shell, wherein a critical surface tension of the shell is smaller than a critical surface tension of the liquid crystal molecule. Further, the liquid crystal molecule includes a nematic liquid crystal and the shell includes polytetramethyldisiloxane. The liquid crystal capsule also includes an additive in the shell and the additive has a critical surface tension smaller than that of the liquid crystal molecule.