Display Encapsulation With Transition-Metal-Oxide Compensation

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Solution Overview

Problem

Existing organic light emitting display devices suffer from afterimages and non-uniform brightness due to oxidation of the second inorganic encapsulation layer, which affects display quality and reliability.

Innovation Solution

Incorporating optical compensation layers made of transition metal oxides, such as cobalt or cerium oxides, on or below the second inorganic encapsulation layers to minimize oxidation and maintain uniform brightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional encapsulation structure is used without optical compensation layer, then the device structure is simpler, but oxidation occurs on the second inorganic encapsulation layer causing afterimages and non-uniform brightness

Engineering Contradiction:

Improvedisplay qualityVSAvoidencapsulation structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

An optical compensation layer comprising a transition metal oxide is introduced as an intermediary between the light emitting element and the second inorganic encapsulation layer. This intermediary layer absorbs excess oxygen and prevents oxidation of the encapsulation layer, thereby eliminating afterimages and non-uniform brightness while maintaining structural integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The encapsulation structure is enhanced by combining inorganic materials with an optical compensation layer made of transition metal oxide. This composite structure leverages the protective properties of inorganic materials and the oxygen absorption properties of transition metal oxides to achieve both structural stability and oxidation prevention.

Inventive Principle:

Principle #40Composite materials

2Illumination intensity

If the second inorganic encapsulation layer is exposed to light from the light emitting element, then the light transmission is maintained, but oxidation occurs leading to afterimages

Engineering Contradiction:

Improvelight transmissionVSAvoidoxidation

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The optical compensation layer utilizing transition metal oxide converts the harmful effect of light-induced oxidation into a beneficial process. The transition metal oxide actively absorbs oxygen and prevents oxidation reactions, transforming the potential harm of light exposure into a protective mechanism that eliminates afterimages.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If no optical compensation layer is included, then the manufacturing process is simpler, but non-uniform brightness occurs due to partial oxidation

Engineering Contradiction:

Improvemanufacturing processVSAvoidbrightness uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The optical compensation layer is incorporated into the encapsulation structure during the manufacturing process to perform preliminary protection against oxidation. By including this layer in advance, the device prevents non-uniform brightness and afterimages before they can occur during operation, ensuring consistent brightness uniformity.

Inventive Principle:

Principle #10Preliminary action

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

Reduces afterimages and enhances display quality by stabilizing the second inorganic encapsulation layer, improving moisture and oxygen proof functions, thereby increasing the reliability of the display device.

Implementation Method 1

an optical compensation layer, which is disposed on or below the second inorganic encapsulation layer, and includes or be formed of a transition metal oxide

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

reducing or minimizing the occurrence of an afterimage of a display device due to oxidation by light emitted from the light emitting element

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 3

a light emitting element (for example, a light emitting diode, especially an organic light emitting diode) on the display area

Methodology Applied

Scientific EffectLight emitting: Light Emitting Diode

Data Source

PatentUS20250275420A1Display device

Publication Date: 2025.08.28 LG DISPLAY CO LTD

AI summary

According to an aspect of the present disclosure, there is provided a display device. The display device includes a substrate which includes a display area and a non-display area adjacent to the display area, a light emitting element such as a light emitting diode on the display area, a first inorganic encapsulation layer on the light emitting element, an organic encapsulation layer on the first inorganic encapsulation layer, a second inorganic encapsulation layer on the organic encapsulation layer, and an optical compensation layer, which is disposed on or below the second inorganic encapsulation layer, and includes or is formed of a transition metal oxide. Therefore, it can reduce or minimize the oxidation of the second inorganic encapsulation layer and suppress occurrence of an afterimage.