OLED First Electrode Segmentation for Dark Spot Repair

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Solution Overview

Problem

Organic light emitting display devices face issues with dark spot defects due to foreign substances on electrodes, which are difficult to repair without causing additional defects, especially in non-repairable locations, leading to reduced yield and visibility.

Innovation Solution

The design incorporates a first electrode with alternating patterns that are partially recessed and protruded, allowing for electrical disconnection of defective areas and connection to adjacent sub-pixels through a repair pattern, reducing dark spots via light diffusion and improving repair efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a foreign substance remains on the first electrode, then dark spot defects occur, but repair techniques can normalize the affected area

Engineering Contradiction:
Improvedisplay qualityVSAvoidrepairability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The first electrode is divided into multiple segments (first, second, third, and fourth electrodes) with insulating regions between them. This segmentation allows defective portions to be isolated and repaired independently without affecting the entire electrode structure, enabling localized repair while maintaining overall display quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the electrode structure are assigned different functions: light-emitting regions for display and insulating regions for electrical isolation. The insulating regions specifically provide local quality by preventing electrical interference between adjacent electrode segments, enabling targeted repair of defective areas.

Inventive Principle:
Principle #3Local quality

2Reliability

If repair techniques are applied to normalize defective areas, then dark spot defects are reduced, but additional defects may be introduced

Engineering Contradiction:
Improvedisplay qualityVSAvoidadditional defects
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Insulating regions are pre-formed between adjacent electrode segments during the manufacturing process, before defects occur. This preliminary structural preparation enables future repair operations to be performed safely without risking damage to neighboring electrodes, as the insulating barriers are already in place.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Insulating regions act as intermediary elements between adjacent light-emitting electrodes. These intermediaries prevent electrical interaction between segments, allowing repair processes to be applied to one segment without causing harmful effects to adjacent segments.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of repair

If the first electrode is designed with alternating patterns including insulating regions, then repair efficiency is improved, but device complexity increases

Engineering Contradiction:
Improverepair efficiencyVSAvoidelectrode structure
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The electrode is segmented into discrete units with insulating regions, which simplifies the repair process by allowing individual segments to be addressed separately. While the overall structure becomes more complex, the modular design actually reduces repair complexity by enabling targeted interventions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The alternating pattern of light-emitting and insulating regions serves multiple functions: electrical isolation, mechanical support, and repair facilitation. This multi-functionality justifies the increased structural complexity by providing inherent repair capabilities without requiring additional separate components.

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

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

This solution effectively reduces dark spot defects and enhances the visibility and yield of organic light emitting display devices by allowing for seamless light emission even with foreign substances present, through the use of interdigitated patterns and a repair mechanism that connects adjacent sub-pixels.

Implementation Method 1

a visible light generated from the organic light emitting layer

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

reducing dark spots via light diffusion

Methodology Applied
Scientific EffectLight diffusion: Diffusion

Data Source

PatentEP3188166B1Organic light emitting display device
Publication Date: 2022.01.05 LG DISPLAY CO LTD
  • EP3188166B1 patent drawingFigure 1
  • EP3188166B1 patent drawingFigure 2
  • EP3188166B1 patent drawingFigure 3

AI summary

Disclosed is an organic light emitting display device including a plurality of sub-pixels on an array substrate in which each sub-pixel includes a circuit part (TFT) including a switching transistor, a driving transistor and a capacitor; and a light emitting part having a shape defined with a width and a length and including a first electrode (370) electrically connected to the driving transistor, an organic light emitting layer and a second electrode, the first electrode (370) including a first pattern (371) having a recess, a second pattern (272) having a protrusion received in the recess, and a third pattern (273) connecting the first and second patterns, wherein a depth of the recess is greater than a half of a longer of the width and the length of the light emitting part.