Quantum Dot Light Emitting Device Segmentation for Backlight Efficiency

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Solution Overview

Problem

In liquid crystal display devices, the existing quantum dot light emitting technologies face inefficiencies in light conversion due to the absorption and re-conversion of green converted light, leading to reduced overall light conversion efficiency and potential damage from high temperatures.

Innovation Solution

A quantum dot light emitting device is designed with a first and second quantum dot package layer, where the first layer generates red light and the second layer generates green light, with a dichroism component to prevent re-absorption of green light, and a thermal insulation layer to manage heat, enhancing light conversion efficiency and preventing material failure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If quantum dot materials are used to convert light wavelengths, then color gamut is improved to 100% NTSC or above, but light conversion efficiency is reduced due to absorption and re-conversion of green light

Engineering Contradiction:

Improvecolor gamutVSAvoidlight conversion efficiency

Core Design Contradiction:

Illumination intensityVSLoss of energy

Solution Approach 1:

The quantum dot package layer is segmented into a first quantum dot package layer (containing red quantum dots) and a second quantum dot package layer (containing green quantum dots). This segmentation prevents green converted light from being re-absorbed by red quantum dots, thereby improving light conversion efficiency while maintaining high color gamut.

Inventive Principle:

Principle #1Segmentation

2Volume of moving object

If quantum dot package layer is placed close to light emitting device, then device size is reduced, but temperature increases causing potential damage to quantum dot materials

Engineering Contradiction:

Improvedevice sizeVSAvoidheat temperature

Core Design Contradiction:

Volume of moving objectVSTemperature

Solution Approach 1:

The quantum dot package layer is divided into two separate layers (first and second quantum dot package layers) positioned at different distances from the light emitting device. This allows the green quantum dots to be placed closer to the light emitting device while red quantum dots are positioned farther away, managing heat distribution and preventing material damage.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A dichroism component is introduced as an intermediary element between the quantum dot package layers and the light emitting device. This component helps manage light paths and heat distribution, enabling the device to maintain a compact size while protecting quantum dot materials from excessive heat.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If green converted light is re-absorbed and re-converted, then light utilization is improved, but overall light conversion efficiency is reduced due to energy loss

Engineering Contradiction:

Improvelight utilizationVSAvoidlight conversion efficiency

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

By segmenting the quantum dot package layer into distinct first and second layers for red and green quantum dots respectively, the patent prevents green converted light from traveling back through the red quantum dot layer. This eliminates unnecessary re-absorption and re-conversion cycles, improving overall light conversion efficiency while maintaining effective light utilization.

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 improves light conversion efficiency by minimizing re-conversion of green light and extends the lifespan of quantum dot materials by managing thermal stress, resulting in enhanced performance and reliability of the liquid crystal display devices.

Implementation Method 1

a first quantum dot package layer configured to absorb the exciting light at the first wavelength, and to generate converted light at a second wavelength

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

a second quantum dot package layer configured to absorb the exciting light at the first wavelength, and to generate converted light at a third wavelength

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 3

can emit stronger light than that emitted by fluorophores in a narrow wavelength range due to quantum confinement effect

Methodology Applied

Scientific EffectQuantum confinement effect:

Data Source

PatentUS10203547B2Quantum dot light emitting device, backlight module, and liquid crystal display device

Publication Date: 2019.02.12 HISENSE USA CORP

AI summary

This disclosures provides a quantum dot light emitting device, a backlight module, and a liquid crystal display device, the quantum dot light emitting device including: a light emitting device configured to generate exciting light at a first wavelength; a first quantum dot package layer configured to absorb the exciting light at the first wavelength, and to generate converted light at a second wavelength; and a second quantum dot package layer configured to absorb the exciting light at the first wavelength, and to generate converted light at a third wavelength; wherein the first quantum dot package layer is located between the light emitting device and the second quantum dot package layer, and the third wavelength is shorter than the second wavelength, and longer than the first wavelength.