Nanoparticle Color Conversion for LCD Backlight Efficiency

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Solution Overview

Problem

Conventional LCD devices suffer from significant light loss and unsatisfactory color quality due to the absorption of light by the LCD unit and the mismatch between bichromatic white backlights and RGB color filters, leading to inefficient energy use and poor color performance.

Innovation Solution

A light emitting apparatus featuring a blue backlight unit and a color conversion array with nanoparticles that absorb blue light to produce high-purity red and green colors, potentially reducing power consumption by up to 50% and improving color quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional RGB color filter arrays are used, then color display is achieved, but light loss is excessive (over 90% of backlight light is absorbed)

Engineering Contradiction:
Improvelight lossVSAvoidmanufacturing complexity
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent converts the harmful light absorption effect of color filters into a beneficial light emission effect by using fluorescent nanoparticles. Instead of absorbing blue light and wasting it, the nanoparticles absorb the blue light and re-emit it as green or red light with narrow bandwidth, transforming the loss mechanism into a light generation mechanism that improves both efficiency and color quality.

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

Solution Approach 2:

The patent changes the fundamental parameter of light interaction from absorption (color filters) to photoluminescence conversion (fluorescent nanoparticles). This parameter change enables the system to convert blue light into green and red light with high efficiency and narrow emission bandwidth, simultaneously improving light utilization and color performance.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If bichromatic white backlight (blue LED with YAG yellow phosphor) is used, then backlight simplicity is maintained, but color quality is unsatisfactory due to spectral mismatch with RGB color filters

Engineering Contradiction:
Improvebacklight structure simplicityVSAvoidcolor quality
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The patent introduces fluorescent nanoparticles as an intermediary between the blue LED backlight and the display elements. These nanoparticles serve as a spectral conversion layer that transforms the blue light into green and red wavelengths, acting as a mediator that bridges the spectral gap between the simple blue LED source and the requirements for full-color display quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Illumination intensity

If nanoparticles with narrow emission bandwidth are used, then color purity and saturation are improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvecolor purityVSAvoidnanoparticle placement precision
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent segments the color conversion function into separate fluorescent nanoparticle layers for green and red colors, rather than using a single broadband yellow phosphor layer. This segmentation allows each nanoparticle type to be optimized for its specific emission wavelength, achieving high color purity while the layer-based structure simplifies the overall manufacturing process compared to precise pixel-level placement.

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

The solution achieves nearly 50% power consumption reduction and enhances color quality by using nanoparticles to convert blue light into red and green light, simplifying the liquid crystal component control and improving color fidelity.

Implementation Method 1

Nanoparticles that absorb the blue light and generate green light may be located in the green pixel. Nanoparticles that absorb the blue light and generate red light may be located in the red pixel.

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

the organic light emitting compound has an absorption of at least 1000 M-1 cm-1 in a spectral region of 430-500 nanometers (nm)

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP3465332B1Light emitting apparatus and electronic device comprising the same
Publication Date: 2021.07.21 DOW GLOBAL TECHNOLOGIES LLC
  • EP3465332B1 patent drawingFigure 1a~1c
  • EP3465332B1 patent drawingFigure 2a~2c
  • EP3465332B1 patent drawingFigure 3~4

AI summary

A light emitting apparatus affording high quality colors and energy economy and an electronic device comprising the light emitting apparatus.