White Light Source Spectrum Control for Sunlight-Like Color Rendering
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Solution Overview
Problem
Existing artificial light sources fail to accurately reproduce the subtle variations in sunlight due to regional differences and time changes, affecting the perception of colors in works of art and human comfort, while also emitting harmful ultraviolet and blue light components.
Innovation Solution
A white light source system using LED modules with controlled light emission intensities and a phosphor layer, capable of reproducing sunlight variations by approximating blackbody radiation spectra, reducing harmful emissions, and incorporating a database for precise sunlight spectrum control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If sunlight is used for illumination, then all colors existing in nature can be reproduced as original colors, but ultraviolet components promote fading and embrittlement of artworks
Solution Approach 1:
The patent segments the broad sunlight spectrum into multiple discrete wavelength bands (violet 380-420nm, blue 420-500nm, blue-green 480-530nm, green 500-600nm, red 600-780nm) using separate LED light sources. Each LED emits a specific wavelength range, and by combining these segmented spectral components, the system reproduces natural sunlight's color rendering while excluding the harmful ultraviolet portion below 380nm.
Solution Approach 2:
The patent applies local quality by selectively controlling the spectral composition at different wavelength regions. Each LED group targets a specific wavelength band with optimized emission characteristics, allowing precise control over which spectral components are present (visible light for color rendering) and which are excluded (ultraviolet for artwork protection).
2Object-affected harmful factors
If artificial light sources are used to reduce ultraviolet, then harmful emissions are minimized, but the ability to reproduce sunlight accurately is compromised
Solution Approach 1:
The patent employs a composite light source system combining five different types of LEDs (violet, blue, blue-green, green, red) each with distinct spectral characteristics. This composite approach synthesizes an artificial sunlight spectrum by integrating multiple discrete wavelength bands, achieving comprehensive color rendering (Ra≥95, R9≥90) while maintaining low ultraviolet emission, thereby surpassing the limitations of single-source artificial illuminants.
Solution Approach 2:
The patent creates a multi-functional illumination system that simultaneously achieves: (1) accurate color rendering comparable to natural sunlight, (2) protection of artworks by eliminating ultraviolet damage, (3) energy efficiency through LED technology, and (4) adjustable color temperature (2000K-10000K). This universal solution addresses multiple conflicting requirements that cannot be satisfied by conventional single-purpose light sources.
3Illumination intensity
If LED modules with multiple phosphors are used, then color rendering is improved, but device complexity increases
Solution Approach 1:
The patent extracts the phosphor conversion function from the core light generation process. Instead of using complex multi-phosphor layers to generate all wavelengths, the system directly emits specific wavelength bands using five types of LEDs, and uses phosphors only for wavelength conversion where needed (e.g., converting violet LED light to blue-green or green ranges). This extraction simplifies the overall structure by eliminating the need for complex multi-layer phosphor assemblies.
Solution Approach 2:
The patent uses phosphor materials to copy or convert specific wavelength characteristics from one LED type to another. For example, violet LEDs (380-420nm) excite phosphors that emit in the blue-green (480-530nm) and green (500-600nm) ranges, effectively copying the desired spectral output without requiring direct emission from multiple LED types. This reduces the number of LED components needed while maintaining spectral accuracy.
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 system provides natural and accurate sunlight simulation with fine color variations, enhancing color perception in art appreciation and human comfort by mimicking sunlight's regional and temporal changes, while minimizing harmful emissions.
Implementation Method 1
a phosphor layer, capable of reproducing sunlight variations by approximating blackbody radiation spectra
Implementation Method 2
A white light source system using LED modules with controlled light emission intensities
Implementation Method 3
capable of reproducing sunlight variations by approximating blackbody radiation spectra
Data Source
AI summary
A light emitting device including a substrate, a first light emitter to emit light having a first color temperature, and a second light emitter to emit light having a second color temperature, in which the first light emitter has a first converter including first phosphors and a first resin, each first phosphor having different half-value widths, the second light emitter has a second converter including second phosphors and a second resin, each second phosphor having different peak wavelengths, at least one phosphor of the first converter has a half-value width of 33 nm to 110 nm, a distance between peak wavelengths of at least two phosphors of the second converter is 150 nm or less, and at least one phosphor of the first converter has a particle size of 5 um to 50 um.