Phosphor-Converted White Light Spectrum for High Melanopic Ratio
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Solution Overview
Problem
Existing light emission devices struggle to achieve a high melanopic ratio while maintaining light emission efficiency and high color rendering properties, which are essential for circadian-friendly lighting that supports human circadian rhythms and visual work.
Innovation Solution
A light emission device comprising a light emitting element with a peak wavelength of 400-490 nm and a fluorescent member containing specific fluorescent materials with defined peak wavelengths and full width at half maximum values, ensuring a melanopic ratio within specified ranges across various correlated color temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light emission device uses a blue light emitting element and yellow fluorescent material to achieve white light emission, then the device can provide general lighting functionality, but the melanopic ratio is insufficient to effectively support circadian rhythms
Solution Approach 1:
The patent applies local quality by introducing a specific red fluorescent material (K2SiF6:Mn4+) with a narrow emission bandwidth (14 nm or less FWHM) at a targeted wavelength range (600-650 nm). This localized spectral enhancement in the red region, when combined with the blue emitting element and yellow fluorescent material, creates a specific spectral distribution that achieves high melanopic ratio (0.15 or more) while maintaining overall white light emission functionality.
2Adaptability or versatility
If the light emission spectrum is adjusted to increase melanopic ratio for circadian-friendly lighting, then circadian rhythm support is improved, but light emission efficiency and color rendering properties deteriorate
Solution Approach 1:
The patent applies parameter changes by precisely controlling the full width at half maximum (FWHM) of the red fluorescent material's emission spectrum to be 14 nm or less. This narrow bandwidth parameter, combined with the specific wavelength range (600-650 nm) and the use of a blue light emitting element (400-490 nm), creates an optimized spectral distribution that achieves high melanopic ratio (0.15 or more) while maintaining efficient light emission and good color rendering properties (Ra ≥ 80, R9 ≥ 50).
3Adaptability or versatility
If the red fluorescent material has a broader emission spectrum to improve color rendering, then color rendering properties are enhanced, but the melanopic ratio decreases
Solution Approach 1:
The patent resolves this contradiction by applying local quality through the narrow bandwidth (14 nm or less FWHM) red fluorescent emission at 600-650 nm. This localized spectral contribution provides sufficient color rendering (R9 ≥ 50) while concentrating the energy in a wavelength range that maximizes melanopic stimulation, thereby achieving both good color rendering and high melanopic ratio (0.15 or more) simultaneously.
4Adaptability or versatility
If the light emission device targets high melanopic ratio for circadian-friendly lighting, then circadian rhythm support is improved, but the device complexity increases due to multiple fluorescent materials with specific parameters
Solution Approach 1:
The patent manages device complexity by applying local quality through a targeted approach: using a blue light emitting element (400-490 nm) combined with yellow fluorescent material and a specific red fluorescent material (K2SiF6:Mn4+) with narrow bandwidth (14 nm or less FWHM) at 600-650 nm. This focused spectral design achieves high melanopic ratio (0.15 or more) with a manageable three-component fluorescent system, avoiding the need for complex multi-material compositions.
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 melanopic ratio, suppressing melatonin secretion and enhancing light emission efficiency, suitable for circadian-friendly lighting that supports visual work.
Implementation Method 1
a light emitting element that has a light emission peak wavelength in a range of 400 nm or more and 490 nm or less
Implementation Method 2
a fluorescent member that contains a first fluorescent material having a light emission peak wavelength in a range of 510 nm or more and less than 580 nm, a second fluorescent material having a light emission peak wavelength in a range of 580 nm or more and 680 nm or less
Data Source
AI summary
A light emission device including a light emitting element having a light emission peak wavelength in a range of 400 nm or more and 490 nm or less, and a fluorescent member including a first fluorescent material having a light emission peak wavelength in a range of 510 nm or more and less than 580 nm, a second fluorescent material having a light emission peak wavelength in a range of 580 nm or more and 680 nm or less and a full width at half maximum of 15 nm or more and 100 nm or less, and a third fluorescent material having a light emission peak wavelength in a range of 600 nm or more and 650 nm or less and a full width at half maximum of 14 nm or less, and having a melanopic ratio (MR) value in a specified range at a certain correlated color temperature.