Organic EL Device Segmentation for Luminance and Transparency

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Solution Overview

Problem

Existing organic electroluminescence (EL) displays face issues with reduced luminance and increased power consumption due to the need for increased light emission area, leading to decreased transparency and shorter element lifetime.

Innovation Solution

The organic electroluminescence device incorporates a base material with recessed portions, a reflective layer, a filling layer, and transparent electrodes, partitioning the display region into light emitting and transmissive areas to enhance light utilization efficiency and transparency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the light emission area is increased to achieve required luminance, then the luminance is improved, but the transparency is decreased and power consumption is increased

Engineering Contradiction:

ImproveluminanceVSAvoidtransparency area

Core Design Contradiction:

Illumination intensityVSArea of stationary object

Solution Approach 1:

The display region is divided into multiple unit regions, each containing a light emitting area and a transmissive area. This segmentation allows different portions of the device to serve different functions: the light emitting areas collectively provide the required luminance while the transmissive areas maintain transparency, resolving the contradiction between luminance and transparency.

Inventive Principle:

Principle #1Segmentation

2Illumination intensity

If the light emission area is increased to achieve required luminance, then the luminance is improved, but the power consumption is increased

Engineering Contradiction:

ImproveluminanceVSAvoidpower consumption

Core Design Contradiction:

Illumination intensityVSUse of energy by moving object

Solution Approach 1:

By segmenting the display into unit regions with dedicated light emitting and transmissive areas, the light emitting elements only need to illuminate their specific light emitting areas. This reduces the total active light emitting area required compared to a fully illuminated display, thereby reducing power consumption while maintaining required luminance in the light emitting portions.

Inventive Principle:

Principle #1Segmentation

3Illumination intensity

If the light emission area is increased to achieve required luminance, then the luminance is improved, but the element lifetime is decreased

Engineering Contradiction:

ImproveluminanceVSAvoidelement lifetime

Core Design Contradiction:

Illumination intensityVSDuration of action of moving object

Solution Approach 1:

The division into unit regions with separate light emitting and transmissive areas reduces the overall active light emitting area. Since organic EL elements have limited lifetimes due to material degradation under continuous operation, reducing the active area decreases the total stress on the light emitting materials, thereby extending element lifetime while maintaining required luminance in the light emitting portions.

Inventive Principle:

Principle #1Segmentation

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 configuration achieves high light emitting efficiency, maintains high transmittance, and extends the element's lifetime by optimizing the light emitting area and reducing power consumption.

Implementation Method 1

a reflective layer... The reflective layer is disposed at least on a surface of the recessed portion

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

an organic layer including at least a light emitting layer... Organic electroluminescence device

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS10826021B2Organic electroluminescence device including a plurality of unit regions each including a light emitting area and a transmissive area

Publication Date: 2020.11.03 SHARP KK

AI summary

An organic electroluminescence device according to one aspect of the disclosure includes a base material including a recessed portion on an upper face, and a light emitting element including a reflective layer, a filling layer having optical transparency, a first electrode having optical transparency, an organic layer including at least a light emitting layer, and a second electrode having optical transparency. The reflective layer is disposed at least on a surface of the recessed portion. The filling layer is disposed at an inside of the recessed portion with the reflective layer interposed between the recessed portion and the filling layer. The first electrode is disposed at least on an upper-layer side of the filling layer. The organic layer is disposed on an upper layer of the first electrode. The second electrode is disposed on an upper-layer side of the organic layer. The organic electroluminescence device includes a display region that is divided into a plurality of unit regions. The plurality of unit regions each having the light emitting element has a light emitting area and a transmissive area that are partitioned.