Optical Member Oxygen Barrier for Wavelength Conversion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Display devices with backlight units face challenges in maintaining reliability and durability due to oxygen ingress and heat sensitivity in their wavelength conversion layers, which can affect the performance and longevity of the optical members.

Innovation Solution

Incorporating an oxygen barrier within the wavelength conversion layer, which is diffused and bonded with polymers during heat treatment, enhances the air-tightness and heat-resistance characteristics of the optical member and display device, thereby improving durability and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the wavelength conversion layer is made transparent and uses polymer materials, then the light transmission efficiency is improved, but the oxygen barrier property deteriorates leading to reduced reliability

Engineering Contradiction:
Improvelight transmission efficiencyVSAvoidoxygen barrier property
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies composite materials by combining polymer materials with inorganic oxygen barrier particles (such as silica, alumina, or titania) within the wavelength conversion layer. This creates a composite structure where the polymer provides light transmission while the inorganic particles provide oxygen barrier properties, thus resolving the contradiction between transparency and oxygen protection.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent introduces an oxygen barrier layer as an intermediary component between the wavelength conversion layer and the external environment. This intermediate layer specifically addresses the oxygen barrier deficiency of transparent polymer materials without affecting their light transmission properties, allowing both requirements to be satisfied simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the quantum dot particle size is reduced to convert blue light, then the wavelength conversion accuracy is improved, but the particle stability deteriorates due to increased surface area

Engineering Contradiction:
Improvewavelength conversion accuracyVSAvoidparticle stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent uses composite materials by embedding quantum dots in a stabilizing matrix or coating them with protective shells. This composite structure maintains the small particle size needed for accurate blue light conversion while the surrounding matrix or shell provides structural stability and reduces surface-related degradation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by providing enhanced protection specifically at the particle surface through coatings or shell structures. This localized intervention addresses the stability issue at the particle level without affecting the overall wavelength conversion accuracy achieved by the small particle size.

Inventive Principle:
Principle #3Local quality

3Device complexity

If the optical member structure is simplified, then the manufacturing cost is reduced, but the heat resistance deteriorates leading to reduced durability

Engineering Contradiction:
Improvestructural simplicityVSAvoidheat resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies multi-functionality by designing the wavelength conversion layer to simultaneously perform wavelength conversion and heat management functions. By incorporating materials with appropriate thermal properties and designing the layer structure to facilitate heat dissipation, the single layer serves multiple purposes, maintaining simplicity while improving heat resistance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses parameter changes by selecting and optimizing material properties such as thermal conductivity, heat capacity, and operating temperature ranges. By adjusting these parameters in the wavelength conversion layer materials and structure, the layer can maintain simplicity while achieving improved heat resistance through careful parameter selection.

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 solution effectively reduces oxygen introduction into the wavelength conversion layer, maintains the stability of wavelength conversion particles, and enhances the overall reliability and durability of the optical member and display device by improving air-tightness and heat-resistance.

Implementation Method 1

an oxygen barrier which reduces permeation of oxygen

Methodology Applied
Scientific EffectOxygen barrier: Diffusion Barrier

Implementation Method 2

wavelength conversion particles which convert wavelength of light

Methodology Applied
Scientific EffectWavelength conversion: Photoluminescence

Implementation Method 3

means for effectively transferring the light emitted from the light emitting device to the liquid crystal

Methodology Applied
Scientific EffectLight transmission: Refraction

Data Source

PatentEP2771737B1Optical member
Publication Date: 2021.09.29 LG INNOTEK CO LTD
  • EP2771737B1 patent drawingFigure 1~2
  • EP2771737B1 patent drawingFigure 3~4
  • EP2771737B1 patent drawingFigure 5~8

AI summary

Disclosed are an optical member, a display device including the same, and a method of fabricating the same. The optical member includes a first substrate; a wavelength conversion layer on the first substrate; and a second substrate on the wavelength conversion layer, wherein the wavelength conversion layer includes an oxygen barrier.