Wavelength Conversion Sealing for Display Durability

Solution Overview

Problem

Liquid crystal display devices using wavelength conversion materials are vulnerable to degradation from oxygen and moisture, particularly on their side surfaces which are not adequately protected by traditional sealing methods, leading to potential bluish light emission issues.

Innovation Solution

A display device design incorporating a sealing member with a light shielding material, such as a black polymer resin, around the side surfaces of the wavelength conversion layer, along with an auxiliary sealing member and a passivation film made of silicon oxide or aluminum oxide, to prevent exposure to oxygen and moisture and block visible light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a wavelength conversion material is coated on the light guide plate to convert blue light into white light, then image quality such as color reproducibility is improved, but the side surface of the wavelength conversion layer is exposed to oxygen and moisture causing degradation

Engineering Contradiction:

Improvecolor reproducibilityVSAvoidresistance to oxygen and moisture degradation

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

A sealing member in the form of a thin film or shell structure is introduced to cover and seal the side surface of the wavelength conversion layer. This sealing member acts as a protective barrier that prevents oxygen and moisture from reaching the wavelength conversion material, thereby resolving the contradiction between maintaining color reproduction quality and preventing environmental degradation.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The sealing member is constructed using composite material structure, combining materials with different properties - one that provides sealing functionality and another that provides light shielding. This composite approach allows the sealing member to simultaneously protect against moisture penetration and prevent light leakage, addressing both the reliability and image quality concerns.

Inventive Principle:

Principle #40Composite materials

2Reliability

If the wavelength conversion layer is sealed with protective films, then degradation from oxygen and moisture is prevented, but visible light can still leak from the side surface causing bluish phenomenon

Engineering Contradiction:

Improveprotection from oxygen and moistureVSAvoidbluish light emission

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The sealing member is constructed using composite material structure, combining materials with different properties - one that provides sealing functionality and another that provides light shielding. This composite approach allows the sealing member to simultaneously protect against moisture penetration and prevent light leakage, addressing both the reliability and image quality concerns.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The sealing member is designed to perform multiple functions simultaneously: it acts as both a moisture barrier and a light shield. By integrating these two functions into a single component, the sealing member prevents both environmental degradation and light leakage without requiring separate structures, thereby eliminating the bluish phenomenon while maintaining protection.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of manufacture

If the side surface of the wavelength conversion layer is left uncovered, then manufacturing process is simplified, but the wavelength conversion material is vulnerable to degradation and light leakage

Engineering Contradiction:

Improvecoating process simplicityVSAvoidprotection from degradation and light leakage

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

A sealing member in the form of a thin film or shell structure is introduced to cover and seal the side surface of the wavelength conversion layer. This sealing member acts as a protective barrier that prevents oxygen and moisture from reaching the wavelength conversion material, thereby resolving the contradiction between maintaining color reproduction quality and preventing environmental degradation.

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

Effectively protects the wavelength conversion material from degradation, preventing bluish light emission and enhancing the durability and image quality of the display device.

Implementation Method 1

a sealing member surrounding a side surface of the optically functional layer... The sealing member may include a light shielding material that substantially blocks visible light

Methodology Applied

Scientific EffectLight shielding: Absorption (EM radiation)

Implementation Method 2

a passivation film disposed to cover exposed surfaces of the optically functional layer and the sealing member

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentUS10416501B2Display device and manufacturing method thereof

Publication Date: 2019.09.17 SAMSUNG DISPLAY CO LTD

AI summary

A display device and a manufacturing method of a display device are provided. The display device comprises: an optically functional layer including a wavelength conversion material; a display panel disposed on the optically functional layer and having at least one side which protrudes outward from an edge of the optically functional layer; and a sealing member surrounding a side surface of the optically functional layer and disposed such that at least a portion of the sealing member is in contact with a lower surface of the protruding portion of the display panel, wherein the sealing member includes a light shielding material that substantially blocks visible light.