OLED Surface Structures for Vehicle Light Masking

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Solution Overview

Problem

The challenge is to enhance the usability and availability of Organic Light-Emitting Diodes (OLEDs) for vehicle lights, as they face issues with moisture, high temperatures, and defects such as dark spots and pixel shrinkage, leading to high reject rates and increased production costs.

Innovation Solution

A method is introduced to treat the surfaces of OLEDs by applying structures that create a light-dark contrast on the luminous and rear surfaces, using materials that promote or prevent light coupling, thereby distracting from defects and improving light extraction efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If OLEDs are used as light sources in vehicle lights, then cost advantages and homogeneous luminous appearance are improved, but reliability under harsh environmental conditions deteriorates due to moisture penetration and high temperatures

Engineering Contradiction:
Improvemanufacturing costVSAvoidservice life under environmental stress
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies a thin glass encapsulation layer to protect the OLED from moisture and oxygen penetration, while maintaining the thin-film structure that enables cost-effective manufacturing. The glass layer acts as a barrier film that prevents environmental degradation without significantly increasing device thickness or production complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent combines organic light-emitting materials with inorganic glass encapsulation to create a composite structure that leverages the advantages of both materials: the organic layer provides flexible, cost-effective light emission while the inorganic glass layer provides robust protection against moisture and temperature stress.

Inventive Principle:
Principle #40Composite materials

2Reliability

If glass encapsulation is used to protect against moisture and oxygen, then reliability is improved, but manufacturing complexity and cost increase compared to plastic alternatives

Engineering Contradiction:
Improvesealing performanceVSAvoidencapsulation structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a thin glass encapsulation layer that provides effective sealing against moisture and oxygen while maintaining a simple, thin-film structure. The thin-film approach minimizes added complexity and thickness compared to bulk encapsulation methods.

Inventive Principle:
Principle #30Flexible shells and thin films

3Manufacturing precision

If OLED manufacturing is optimized for vehicle applications, then quality is improved, but productivity decreases due to high reject rates from stringent quality requirements

Engineering Contradiction:
Improvequality standardVSAvoidproduction output
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies a light-extraction-promoting structure that modifies the optical properties of the OLED surface, enhancing light output and creating a visually dominant pattern that masks minor manufacturing defects such as dark spots and pixel shrinkage, thereby reducing reject rates while maintaining quality standards.

Inventive Principle:
Principle #32Color changes

4Illumination intensity

If light extraction efficiency is increased, then luminous output is improved, but manufacturing precision requirements increase due to sensitivity to defects

Engineering Contradiction:
Improveluminous outputVSAvoiddefect tolerance
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent applies a light-extraction-promoting structure that enhances light output while creating a visually dominant optical pattern that masks minor manufacturing defects, thereby increasing luminous efficiency without proportionally increasing precision requirements.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent modifies the optical parameters of the OLED surface by applying a light-extraction-promoting structure, changing the refractive index profile and light extraction characteristics to improve luminous output while the resulting optical pattern provides defect masking.

Inventive Principle:
Principle #35Parameter changes

5Reliability

If surface structures are applied to mask defects, then usability is improved, but device complexity increases

Engineering Contradiction:
ImproveusabilityVSAvoidsurface structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies a light-extraction-promoting structure that creates a visually dominant optical pattern to mask defects, improving usability while maintaining a relatively simple surface modification approach.

Inventive Principle:
Principle #32Color 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

This approach increases the usability of OLEDs by masking defects, enhancing light output, and extending the lifespan of OLEDs, ultimately reducing production costs and environmental impact while improving the quality and availability of OLEDs for vehicle applications.

Implementation Method 1

A light-extraction-promoting structure is applied to at least one surface of an OLED... which structure... increases light output from the OLED

Methodology Applied
Scientific EffectLight extraction: Refraction

Data Source

PatentEP3407400B1Method for treating the surfaces of oleds intended for use as light sources in vehicle lights and light source with at least one correspondingly treated OLED as light source
Publication Date: 2023.07.05 ODELO
  • EP3407400B1 patent drawingFigure 1
  • EP3407400B1 patent drawingFigure 2
  • EP3407400B1 patent drawingFigure 3

AI summary

A method for treating at least one surface (12, 13) of an OLED (01) intended as a light source in a vehicle lamp and a light source for fulfilling a lighting function of a vehicle lamp or for contributing to a predetermined light distribution of a lighting function of a vehicle lamp are described. The OLED (01) has a luminous surface (02) intended for frontal light emission and a rear surface (03) opposite the luminous surface (02). The method provides for the deposition of one or more structures (06) at least on the luminous surface (02) and/or the rear surface (03), which structure (06) generates a light-dark contrast at least within the area defined by the luminous surface (02), at least when warm.The structure (06) is applied at least within the area occupied by the luminescent surface (02) on the surface (12) of the OLED (01) encompassing the luminescent surface (02) and/or on the surface (13) of the OLED (01) encompassing the rear surface (03) opposite the luminescent surface (02). To maintain the light-dark contrast on the finished surface (12, 13) of the OLED (01), the application comprises: - several sections (07) separated from one another by parts of the structure (06) that are free of the structure (06), and/or - several sections of the structure (06) separated from one another by sections (07) that are free of the structure (06). The light source comprises at least one OLED (01) treated according to such a method as a light source.