Phosphor-Tuned Light Emission for Circadian-Friendly Color Rendering
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Solution Overview
Problem
Current light emitting devices do not effectively balance color rendering properties and melanopic ratios to mimic natural light, affecting human circadian rhythms and comfort in various environments.
Innovation Solution
A light emitting device comprising a light emitting element and a fluorescent member with specific phosphor compositions and content percentages, optimized to achieve a targeted melanopic ratio and correlated color temperature, ensuring comfort and visibility by stimulating the intrinsically photosensitive retinal ganglion cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional phosphors are used in light emitting devices, then manufacturing cost and ease of manufacture are maintained, but color rendering properties and melanopic ratio do not adequately align with natural light conditions
Solution Approach 1:
The patent applies parameter changes by precisely controlling the composition ratios of multiple phosphors (yellow phosphor, orange phosphor, red phosphor) to achieve specific melanopic ratios and color rendering properties. By adjusting phosphor content percentages and selecting specific phosphor materials with defined characteristics, the invention optimizes the spectral power distribution to match natural light conditions while maintaining manufacturability through standardized phosphor selection.
Solution Approach 2:
The invention uses composite materials by combining multiple phosphor types (yellow, orange, red) with specific compositions to create a fluorescent member that produces light with improved color rendering and appropriate melanopic ratio. The composite phosphor system allows tuning of spectral characteristics to achieve natural light-like properties while maintaining practical manufacturing considerations.
2Ease of operation
If light emitting devices are designed to match natural light conditions, then visibility and comfort are improved, but device complexity increases due to multiple phosphor requirements
Solution Approach 1:
The patent applies local quality by assigning specific functions to different phosphor components within the fluorescent member. Each phosphor type (yellow, orange, red) contributes specific spectral characteristics that collectively achieve natural light-like properties. This functional differentiation within the composite material allows optimization of visibility and comfort while managing device complexity through specialized component roles.
3Reliability
If the melanopic ratio is optimized for circadian rhythm, then health comfort is improved, but color temperature control becomes more constrained
Solution Approach 1:
The patent applies dynamics by enabling adjustment of both melanopic ratio and color temperature through varying phosphor composition ratios. The fluorescent member can be configured to achieve different melanopic ratios (e.g., 0.5-1.5) while maintaining color temperatures in practical ranges (2000K-10000K), allowing the light emitting device to adapt to different usage scenarios and time of day requirements for circadian rhythm management.
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 provides improved color rendering properties and a specific melanopic ratio, promoting comfort and visibility by adjusting the light emission to match natural light conditions, suitable for different usage environments.
Implementation Method 1
a light emitting device that emits mixed color light by using a light emitting element that emits blue light and a phosphor that emits light when excited by the light from the light emitting element
Implementation Method 2
The ipRGC contains a visual pigment called melanopsin, gives a light stimulus to a suprachiasmatic nucleus that manages a circadian rhythm of mammals, and performs a nerve response
Data Source
AI summary
A light emitting device includes a light emitting element, and a fluorescent member including a phosphor. The light emitting device satisfies any of Condition (A): a correlated color temperature of light emission of the light emitting device is within a range of 4500 K or more and 7500 K or less, a content of a first phosphor is within a range of 29 mass % or more and 90 mass % or less, and a melanopic ratio is within a range of 1.0 or more and 1.4 or less; Condition (B): a correlated color temperature of light emission of the light emitting device is within a range of 2500 K or more and less than 4500 K, a content of a first phosphor is within a range of 25 mass % or more and 90 mass % or less, and a melanopic ratio is within a range of 0.7 or more and 1.1 or less; and Condition (C): a correlated color temperature of light emission of the light emitting device is within a range of 2500 K or more and 3000 K or less, a content of a first phosphor is within a range of 20 mass % or more and 90 mass % or less, and a melanopic ratio is within a range of 0.48 or more and 1.10 or less.