Liquid Crystal Optical Layer Structure for Thermal Deformation Control

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Solution Overview

Problem

Optical devices face challenges in maintaining durability due to thermal deformation and varying transmittance, which is affected by the difference in elastic modulus and thermal expansion coefficients between substrates and polarizing layers.

Innovation Solution

Incorporating a liquid crystal layer with a liquid crystal compound that changes transmittance based on external actions, and strategically designing the positions and structures of substrates and polarizing layers to minimize stress and deformation, allowing the device to switch between transmissive and blocking modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a substrate and polarizing layer are combined to form an optical device, then the device can perform optical functions, but thermal deformation occurs due to differences in elastic modulus and thermal expansion coefficients

Engineering Contradiction:
ImprovedurabilityVSAvoidthermal deformation
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by carefully selecting and adjusting the elastic modulus and thermal expansion coefficient parameters of the substrate and polarizing layer materials. By matching these parameters within specific ranges, the patent reduces thermal deformation while maintaining optical functionality. This is achieved through material selection and compositional adjustment rather than structural modification.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a liquid crystal layer is added to enable transmittance switching, then the device can switch between transmissive and blocking modes, but the device becomes more susceptible to thermal deformation

Engineering Contradiction:
Improvetransmittance switchingVSAvoidthermal deformation
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent uses composite materials by combining the liquid crystal layer with specifically designed substrate and polarizing layer materials that have matched elastic moduli and thermal expansion coefficients. This composite structure allows the liquid crystal layer to provide transmittance switching functionality while the matched materials minimize thermal deformation across the entire device structure.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If the device structure is simplified to reduce manufacturing complexity, then manufacturing cost decreases, but stress from thermal expansion differences increases

Engineering Contradiction:
Improvemanufacturing complexityVSAvoidthermal stress
Core Design Contradiction:
Ease of manufactureVSStress or pressure

Solution Approach 1:

The patent applies parameter changes by optimizing the thickness and material composition parameters of each layer to achieve a balance between manufacturing simplicity and stress reduction. By adjusting these parameters within specific ranges, the patent reduces thermal stress without requiring complex multi-layer structures or additional stress-compensation components.

Inventive Principle:
Principle #35Parameter changes

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 optical device achieves a transmittance change rate of ±10% or less after a heat resistance test, effectively preventing deformation and maintaining low haze values, even in the absence of external actions.

Implementation Method 1

a liquid crystal layer having a liquid crystal compound, wherein a transmittance of the optical device varies depending on whether or not an external action is applied

Methodology Applied
Scientific EffectLiquid crystal effect: Liquid Crystals

Implementation Method 2

the difference in an elastic modulus and a coefficient of thermal expansion between a substrate and a polarizing layer or between the substrate and other layers

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3385781B1Optical element
Publication Date: 2024.05.15 LG CHEM LTD
  • EP3385781B1 patent drawingFigure 1~2
  • EP3385781B1 patent drawingFigure 3~4
  • EP3385781B1 patent drawing

AI summary

The present application relates to an optical device and a use thereof. The optical device of the present application is a member in which transmittance can vary depending on whether or not an external action is present, and has excellent durability.