OLED Reflective Layer UV Wavelength Filtering

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional OLED displays are susceptible to deterioration of electrical characteristics due to ultraviolet (UV) radiation, which causes thermal damage and affects the organic thin film layer and surface characteristics, especially in thin or flexible displays where traditional sealing methods are challenging to apply.

Innovation Solution

An OLED display with a reflective layer comprising laminated materials of different refractive indices and an encapsulation layer that includes both organic and inorganic thin films, where the refractive indices of the materials are chosen to minimize the impact of UV radiation, and the encapsulation layer uses UV radiation curing materials to prevent thermal damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UV radiation is used to cure the encapsulation layer, then the encapsulation is formed successfully, but thermal damage is generated affecting the organic thin film layer and surface characteristics

Engineering Contradiction:

Improveencapsulation formationVSAvoidthermal damage to organic thin film layer

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A reflective layer is introduced as an intermediary component between the OLED and the encapsulation layer. This reflective layer selectively reflects UV radiation wavelengths that would cause thermal damage to the organic thin film layer while allowing the UV curing process to proceed for the encapsulation layer formation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The solution separates the UV radiation spectrum into different wavelength segments. The reflective layer is designed to reflect specific harmful UV wavelengths while permitting other wavelengths to pass through for effective encapsulation curing, thus segmenting the radiation effects.

Inventive Principle:

Principle #1Segmentation

2Reliability

If traditional sealing methods (can or cup shaped container) are used, then electrical and light emitting characteristics are protected from deterioration, but the display cannot be made thin or flexible

Engineering Contradiction:

Improveprotection from deteriorationVSAvoiddisplay thickness and flexibility

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The invention replaces rigid traditional sealing containers with thin film encapsulation layers that conform to the OLED structure. These thin films provide the necessary protection against moisture and oxygen while maintaining the display's thin and flexible characteristics.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The mechanical sealing system (containers and sealants) is replaced with a thin film encapsulation system that provides protection through material properties rather than physical containment, enabling thin and flexible display construction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If UV radiation is irradiated onto the organic thin film layer, then the encapsulation layer is cured, but the characteristics of the organic thin film layer and surface characteristics are negatively affected

Engineering Contradiction:

Improveencapsulation layer curingVSAvoidorganic thin film layer characteristics

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The reflective layer serves as a mediator that modifies the UV radiation characteristics before they reach the organic thin film layer, allowing encapsulation curing to proceed while preserving the organic layer's characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The reflective layer changes the parameters of UV radiation by selectively reflecting specific wavelengths. This parameter modification allows the curing process to occur at effective wavelengths while blocking wavelengths that would degrade the organic thin film layer.

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 the change in electric characteristics caused by UV radiation, enhancing the luminance and lifespan of the OLED display by preventing thermal damage and moisture/oxygen permeation, making it suitable for thin or flexible OLEDs.

Implementation Method 1

the reflective layer comprising a laminated first material and second material, the first material and the second material having different refractive indices

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

reflective layer on the OLED, the reflective layer comprising a laminated first material and second material

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 3

The organic thin film of the encapsulation layer may include an ultraviolet radiation curing material

Methodology Applied

Scientific EffectPhotopolymerisation: Photopolymerisation

Data Source

PatentUS7875895B2Organic light emitting diode (OLED) display and method of manufacturing the same

Publication Date: 2011.01.25 SAMSUNG DISPLAY CO LTD

AI summary

An organic light emitting display includes a substrate, an OLED including an anode electrode, a cathode electrode and an organic thin film formed between the anode electrode and the cathode electrode, a reflective layer on the OLED, the reflective layer comprising a laminated first material and second material, the first material and the second material having different refractive indices, and an encapsulation layer on the reflective layer, the encapsulation layer comprising at least one of organic thin film and inorganic thin film.