Optical Path Length-Adjusting Layer for Light-Emitting Display

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Solution Overview

Problem

The production process for light-emitting display devices with optical path length-adjusting layers using inorganic materials like ITO is complex, leading to increased costs and reduced productivity due to the need for multiple layers and etching processes.

Innovation Solution

A method involving the use of a light-transmissive resin material, such as a photocurable resin, formed through vapor-phase film forming methods like flash evaporation or spray coating, which simplifies the process by eliminating the need for resist layers and etching, and forms optical path length-adjusting layers with adjusted thicknesses for precise light extraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If inorganic materials like ITO are used to form optical path length-adjusting layers, then the optical path length can be adjusted for light extraction, but the production process becomes complicated with multiple layers and etching processes

Engineering Contradiction:
Improveoptical path length adjustment precisionVSAvoidproduction process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex resist layer formation and etching processes from the production flow. Instead of using inorganic ITO layers requiring photolithography and etching, the invention directly forms organic optical path length-adjusting layers through simple coating and curing processes, eliminating the disturbing resist and etching steps while maintaining optical path length adjustment capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the material parameter from inorganic ITO to organic resin materials, and changes the process parameter from sputtering/vapor deposition with etching to coating/curing processes. This material and process substitution maintains the optical path length adjustment function while dramatically simplifying the production process

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If inorganic materials like ITO are used in optical path length-adjusting layers, then optical path length can be controlled, but production cost increases and productivity decreases

Engineering Contradiction:
Improveoptical path length controlVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent removes the time-consuming resist coating, patterning, and etching steps from the production sequence. By directly forming organic optical path length-adjusting layers through coating and curing, the process eliminates multiple sequential operations, thereby increasing production speed and efficiency while maintaining optical control

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent enables continuous formation of optical path length-adjusting layers across the entire substrate without interruption for resist processing. The coating and curing steps can be performed continuously over large areas, maintaining productive action throughout the process rather than having intermittent stops for complex patterning operations

Inventive Principle:
Principle #20Continuity of useful 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

This method simplifies the production process, reduces costs, and achieves highly definite full-color displays by efficiently forming optical path length differences without the complexity of resist layers and etching, enabling effective light extraction for blue, green, and red wavelengths.

Implementation Method 1

the part being in a region including the at least one pixel region is cured to form a light-transmissive resin layer

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

the forming the film of the light-transmissive resin material is performed by a vapor-phase film forming method

Methodology Applied
Scientific EffectVapor-phase film forming: Physical Vapour Deposition

Data Source

PatentEP2404335B1Method for producing light-emitting display device
Publication Date: 2019.09.11 UDC IRELAND
  • EP2404335B1 patent drawingFigure 1~3
  • EP2404335B1 patent drawingFigure 4~6
  • EP2404335B1 patent drawingFigure 7~8

AI summary

A method for producing a light-emitting display device, the method including forming a film of a light-transmissive resin material on a substrate over which a reflective metal and a semi-transparent member can be disposed in at least one of a plurality of pixel regions corresponding to red, green and blue; curing part of the film of the light-transmissive resin material to form a light-transmissive resin layer, the part being in a region including the at least one pixel region; and developing the light-transmissive resin layer after the curing to form an optical path length-adjusting layer.