White Light Device with Dual Blue LEDs for Gamut and Blue-Light Control

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Solution Overview

Problem

Existing white light emitting devices do not effectively balance color gamut and human-oriented lighting conditions, particularly in terms of blue light hazard and melanopic ratio, limiting their suitability for display applications.

Innovation Solution

A white light emitting device comprising first and second LED chips emitting blue light with different peak wavelengths, combined with specific wavelength conversion materials to produce white light with a melanopic ratio of 1.3 or more and a color gamut covering 90% of the DCI-P3 standard, while minimizing blue light hazard.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional single blue LED chip with wavelength conversion material is used, then device complexity is low, but color gamut coverage is insufficient and melanopic ratio cannot be optimized

Engineering Contradiction:
Improvecolor gamut coverageVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the single blue light source into two separate blue LED chips with different peak wavelengths (430-470nm and 460-480nm). Each chip is paired with specific wavelength conversion materials to generate different spectral components. This segmentation enables independent optimization of each light path to achieve both wide color gamut (90%+ DCI-P3 coverage) and controlled melanopic ratio (1.0-3.0), resolving the contradiction between performance and complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite wavelength conversion materials including yellow phosphors (Y3Al5O12:Ce, Lu3Al5O12:Ce), red phosphors (CaAlSiN3:Eu, Sr2Si5N8:Eu), and green phosphors (β-SiAlON:Eu, (Ba,Sr)2SiO4:Eu). This composite material system transforms the combined output of two blue LED chips into a balanced white light spectrum that achieves 90%+ DCI-P3 color gamut coverage while maintaining melanopic ratio within 1.0-3.0, effectively resolving the technical contradiction.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If blue light intensity is increased to improve color gamut, then color gamut coverage improves, but blue light hazard increases

Engineering Contradiction:
Improvecolor gamut coverageVSAvoidblue light hazard
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent utilizes two blue LED chips with different peak wavelengths (first chip: 430-470nm, second chip: 460-480nm) to create a distributed spectral profile. This parameter diversification spreads the blue light energy across a broader wavelength range, reducing the concentration of energy at any single hazardous wavelength while maintaining overall color gamut coverage of 90%+ DCI-P3. The distinct wavelength separation between the two chips prevents peak intensity concentration, thereby reducing blue light hazard.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite wavelength conversion materials including yellow phosphors (Y3Al5O12:Ce, Lu3Al5O12:Ce), red phosphors (CaAlSiN3:Eu, Sr2Si5N8:Eu), and green phosphors (β-SiAlON:Eu, (Ba,Sr)2SiO4:Eu). This composite material system transforms the combined output of two blue LED chips into a balanced white light spectrum that achieves 90%+ DCI-P3 color gamut coverage while maintaining melanopic ratio within 1.0-3.0, effectively resolving the technical contradiction.

Inventive Principle:
Principle #40Composite materials

3Adaptability or versatility

If wavelength conversion materials are optimized for color gamut, then color gamut coverage improves, but melanopic ratio becomes uncontrolled

Engineering Contradiction:
Improvecolor gamut coverageVSAvoidmelanopic ratio control
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent divides the single blue light source into two separate blue LED chips with different peak wavelengths (430-470nm and 460-480nm). Each chip is paired with specific wavelength conversion materials to generate different spectral components. This segmentation enables independent optimization of each light path to achieve both wide color gamut (90%+ DCI-P3 coverage) and controlled melanopic ratio (1.0-3.0), resolving the contradiction between performance and complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes two blue LED chips with different peak wavelengths (first chip: 430-470nm, second chip: 460-480nm) to create a distributed spectral profile. This parameter diversification spreads the blue light energy across a broader wavelength range, reducing the concentration of energy at any single hazardous wavelength while maintaining overall color gamut coverage of 90%+ DCI-P3. The distinct wavelength separation between the two chips prevents peak intensity concentration, thereby reducing blue light hazard.

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 device achieves a high luminous efficacy and wide color gamut, reducing blue light hazard and enhancing concentration by suppressing melatonin secretion, making it suitable for human-oriented display lighting.

Implementation Method 1

a first wavelength conversion material disposed at a traveling path of light emitted from the first and second LED chips and converting a portion of the emitted light into first light having a peak wavelength in a range of 520 nm to 550 nm

Methodology Applied
Scientific EffectWavelength conversion: Fluorescence

Implementation Method 2

a second wavelength conversion material disposed at the traveling path of the light emitted from the first and second LED chips and converting a portion of the emitted light into second light having a peak wavelength in a range of 610 nm to 650 nm

Methodology Applied
Scientific EffectWavelength conversion: Fluorescence

Data Source

PatentEP4608104A1White light emitting device and display apparatus
Publication Date: 2025.08.27 SAMSUNG ELECTRONICS CO LTD
  • EP4608104A1 patent drawingFigure 1
  • EP4608104A1 patent drawingFigure 2
  • EP4608104A1 patent drawingFigure 3

AI summary

A white light emitting device (100) comprising a first light emitting diode (LED) chip (30A) emitting light having a peak wavelength in a range of 425 nm to 455 nm; a second LED chip (30B) emitting light having a peak wavelength in a range of 460 nm to 470 nm; a first wavelength conversion material (55G) disposed at a traveling path of light emitted from the first and second LED chips (30B) and converting a portion of the emitted light into first light; and a second wavelength conversion material (55R) disposed at the traveling path of the light emitted from the first and second LED chips (30B) and converting a portion of the emitted light into second light, wherein the first light, the second light, the emitted light from each of the first and second LED chips (30B) form a white light as an output of the white light emitting device (100).