Color Conversion Element Light Recycling via Low Refractive Layers

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Solution Overview

Problem

Color conversion elements in display devices suffer from light loss and reduced luminance due to absorption or scattering of light by filter layers containing wavelength conversion particles or scatterers, leading to inefficiencies in light transmission.

Innovation Solution

Incorporating a color conversion element with a base substrate, light shielding member, wavelength conversion pattern layers, and low refractive layers to recycle light that would otherwise be lost, improving light efficiency and luminance by using low refractive layers to induce total reflection and a capping layer to protect the low refractive layers from organic material damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a filter layer containing wavelength conversion particles or scatterer is used to convert light wavelengths, then color conversion is achieved, but light is absorbed or scattered back to the light source without conversion, reducing light efficiency and luminance

Engineering Contradiction:
ImproveluminanceVSAvoidlight efficiency
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent converts the harmful effect of light scattering and absorption back toward the light source into a beneficial recycling mechanism. By placing a light shielding member with reflective properties at the bottom of the color conversion element, unconverted light that would otherwise be lost is reflected back through the wavelength conversion layer, giving it another chance to be converted into useful green and red light components.

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

Solution Approach 2:

The patent recovers light that would normally be discarded or lost in the color conversion process. The light shielding member captures light that transmits through the wavelength conversion layer without being converted, reflects it back, and enables its reuse in the color conversion process, thereby recovering energy that would otherwise be wasted.

Inventive Principle:
Principle #34Discarding and recovering

2Loss of energy

If low refractive layers are used to recycle light, then light efficiency is improved, but the low refractive layers are damaged by adjacent organic material layers in subsequent processes

Engineering Contradiction:
Improvelight efficiencyVSAvoidstructural integrity of low refractive layers
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies a capping layer over the low refractive layer before subsequent processing steps. This capping layer acts as a protective cushion that shields the fragile low refractive layer from damage by adjacent organic material layers during manufacturing processes, ensuring the low refractive layer maintains its structural integrity and optical properties.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The capping layer serves as an intermediary protective element between the low refractive layer and adjacent organic material layers. It mediates the interaction during subsequent processing, preventing direct contact and potential damage between the low refractive layer and organic materials, thus preserving the functionality of the light recycling structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enhances light efficiency and luminance by recycling lost light and maintaining the functionality of low refractive layers, thereby improving the overall performance of the display device.

Implementation Method 1

low refractive layers to induce total reflection

Methodology Applied
Scientific EffectTotal reflection: Total Internal Reflection

Implementation Method 2

layer containing wavelength conversion particles or a scatterer, it can be absorbed or scattered

Methodology Applied
Scientific EffectWavelength conversion: Photoluminescence

Data Source

PatentEP3477369B1Color conversion element and display device including the same
Publication Date: 2022.04.13 SAMSUNG DISPLAY CO LTD
  • EP3477369B1 patent drawingFigure 1
  • EP3477369B1 patent drawingFigure 2
  • EP3477369B1 patent drawingFigure 3

AI summary

Provided are a wavelength conversion element and a display device comprising the same. A color conversion element comprises: a wavelength conversion layer (320); one or more low refractive layers (400a, 400b) which are disposed on and/or under the wavelength conversion layer and have a lower refractive index than the wavelength conversion layer; and one or more capping layers (CL) which are disposed between the wavelength conversion layer and the low refractive layers and/or on a surface opposite to a surface of each of the low refractive layers which faces the wavelength conversion layer.