OLED Shielding Lamella Structure for Glare Reduction

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Solution Overview

Problem

Organic light-emitting diodes (OLEDs) used for large area illumination suffer from glare due to their lambertian characteristic, which causes discomfort by directing artificial light in all directions, including towards observers.

Innovation Solution

A light emitting device with a shielding structure comprising macroscopic lamella elements connected to the basic layer, guiding artificial light out of the device to prevent glare and acting as a heat dissipator through high thermal conductivity connections, such as gluing or welding, to channelize light flux and reduce direct visibility of the light-emitting layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If OLED is used as large area illumination device with high light flux, then illumination intensity is improved, but glare occurs due to lambertian light distribution

Engineering Contradiction:
Improvelight fluxVSAvoidglare
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the light-emitting surface into multiple segments by adding a shielding structure with lamella elements. These elements segment the uniformly emitting OLED surface into multiple zones, redirecting light from different areas to achieve non-uniform angular distribution and reduce glare while maintaining overall illumination intensity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shielding structure acts as an intermediary element between the OLED light source and the observer. It intercepts and redirects the lambertian light distribution, transforming the direct glare-causing light paths into indirect illumination paths that reduce discomfort while preserving light flux.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If shielding structure is added to prevent glare, then glare is reduced, but device complexity increases

Engineering Contradiction:
ImproveglareVSAvoidstructure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The shielding structure is designed to serve multiple functions simultaneously: it prevents glare by controlling light distribution, dissipates heat through thermally conductive connections to the substrate, and maintains mechanical stability. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity.

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

Solution Approach 2:

The patent optimizes parameters of the shielding structure such as the geometry of lamella elements, their spacing, and thermal conductivity properties to achieve effective glare reduction with minimal structural complexity. By carefully selecting these parameters, the design achieves the desired optical performance without excessive complexity.

Inventive Principle:
Principle #35Parameter 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

The solution effectively channels light to illuminate specific areas without glare, providing efficient heat dissipation and ensuring that observers do not have a direct line of sight to the light-emitting layer, thus addressing the glare issue while maintaining high light intensity and efficiency.

Implementation Method 1

the lamella elements guide the artificial light out of the light emitting device

Methodology Applied
Scientific EffectLight guidance: Reflection

Implementation Method 2

acting as a heat dissipator through high thermal conductivity connections, such as gluing or welding

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2135307B1Light emitting device
Publication Date: 2018.09.19 KONINKLIJKE PHILIPS NV
  • EP2135307B1 patent drawingFigure 1
  • EP2135307B1 patent drawingFigure 2
  • EP2135307B1 patent drawingFigure 3

AI summary

The invention relates to a light emitting device (10), comprising a stack of layers (15) of a substrate, with a basic layer (20), a first electrode layer (30) and a second electrode layer (40), wherein an organic light-emitting layer (50) is sandwiched between the first (30) and the second electrode layer (40), the organic light-emitting layer (50) is emitting an artificial light (51). The invention discloses that at least a part of the basic layer (20) is covered by a shielding structure (60), wherein the shielding structure (60) comprises a plurality of lamella elements (70,70'), the lamella elements (70,70') extend sheet like from the stack of layers (15) in such a way, that the lamella elements (70,70') guide the artificial light (51) out of the light emitting device (10).