OLED Color Shift Prevention Layer Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Residual organic material from vapor deposition in OLED displays causes mask deformation, leading to insufficient alignment accuracy and color shift issues due to the weight of residual material affecting the mask openings, resulting in mixed color regions.

Innovation Solution

A color shift prevention layer with opaque patterns is introduced above or under the organic light-emitting layer, specifically designed to block mixed light emitted from mixed color regions, ensuring accurate color alignment and preventing color shifts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If vapor deposition process is used to form organic material layer, then organic material can be deposited onto pre-selected pixel regions, but residual organic material deforms the mask and causes color shift problems

Engineering Contradiction:

Improvevapor deposition processVSAvoidmask alignment accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent converts the harmful effect of residual organic material (which causes mask deformation and color shift) into a beneficial feature by designing the mask with a compensation structure. The residual material is intentionally allowed to deposit on specific compensation regions of the mask, and these regions are pre-designed to counterbalance the deformation, thereby maintaining accurate alignment throughout the vapor deposition process

Inventive Principle:

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

2Quantity of substance

If residual organic material remains near mask openings, then material is available for deposition, but the weight deforms the mask and changes opening shape

Engineering Contradiction:

Improveresidual organic materialVSAvoidmask opening shape

Core Design Contradiction:

Quantity of substanceVSShape

Solution Approach 1:

The patent applies preliminary action by pre-designing the mask structure with compensation regions before the vapor deposition process begins. The mask is configured with specific geometric features and material distribution patterns that anticipate the accumulation of residual organic material, allowing the mask to maintain its functional shape despite the added weight and material deposition

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If mask alignment accuracy is insufficient, then mixed color regions are formed in organic material layer, but color shift problems occur

Engineering Contradiction:

Improvemask alignment accuracyVSAvoidcolor shift

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

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

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 color shift prevention layer effectively shields and blocks mixed light from mixed color regions, resolving color shift problems and improving production yield by maintaining accurate color alignment and preventing color shifts.

Implementation Method 1

the color shift prevention layer is able to shield and block the mixed light emitted from the mixed color regions

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

the organic material layer of an OLED display can be formed by vapor depositing red (R), green (G), blue (B) color organic material layer with a vapor deposition apparatus

Methodology Applied

Scientific EffectVapor deposition: Physical Vapour Deposition

Data Source

PatentUS9640590B2Organic light-emitting diode display and fabrication method thereof

Publication Date: 2017.05.02 ALPHA TOUCH GROUP LLC

AI summary

An organic light-emitting diode (OLED) display and fabrication method thereof are provided. The OLED display includes an organic light-emitting layer comprising a plurality of primary color regions and a plurality of mixed color regions, wherein the primary color regions and the mixed color regions have the same light emitting direction. A color shift prevention layer is disposed above or under the organic light-emitting layer, the color shift prevention layer comprising a plurality of opaque patterns disposed on the light emitting direction of the corresponding mixed color regions. The color shift prevention layer incorporated in the OLED display is able to block the mixed light emitted from the mixed color regions of the organic light-emitting layer. Therefore, the color shift problem can be solved.