LED-Module High Color Rendering Index
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Solution Overview
Problem
Existing white light emitting LED-modules struggle to achieve Color Rendering Index (CRI) values ≥90 across the full range of 2500-8000K, particularly in the range of 2700-6500K, due to limitations in tunability and efficiency of previous RGB and phosphor-based solutions.
Innovation Solution
A 3-channel LED-module configuration using at least two blue LEDs and a red LED, with specific dominant wavelengths and color conversion means, such as inorganic phosphors or quantum dots, applied to the blue LEDs to achieve CRI ≥90 and CCT within 2500-8000K, preferably 2700-6500K, by optimizing the chromaticity coordinates and emission peaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single blue LED with phosphor conversion is used, then the system structure is simple, but the CRI cannot reach ≥90 in the full CCT range of 2500-8000K
Solution Approach 1:
The patent divides the single blue LED into multiple blue LEDs with different dominant wavelengths (first blue LED: 445-465nm, second blue LED: 460-480nm). Each blue LED is paired with specific phosphor materials to create distinct spectral components. This segmentation allows independent optimization of each wavelength component to achieve comprehensive spectral coverage across 2500-8000K CCT range with CRI≥90.
Solution Approach 2:
The patent employs composite phosphor materials including yellow phosphor (Y3Al5O12:Ce, Lu3Al5O12:Ce), red phosphor (CaAlSiN3:Eu, Sr2Si5N8:Eu), and green phosphor (β-SiAlON:Eu, SrSi2O2N2:Eu) in specific combinations. These composite material systems enable precise spectral engineering where each phosphor contributes to specific wavelength regions, achieving full spectral coverage necessary for CRI≥90 across the entire CCT range.
2Manufacturing precision
If multiple phosphor materials are combined to improve CRI, then the CRI increases, but the system complexity and production difficulty increase
Solution Approach 1:
The patent segments the phosphor system into distinct groups associated with each blue LED: first blue LED (445-465nm) uses yellow phosphor (Y3Al5O12:Ce, Lu3Al5O12:Ce) and red phosphor (CaAlSiN3:Eu, Sr2Si5N8:Eu), while second blue LED (460-480nm) uses green phosphor (β-SiAlON:Eu, SrSi2O2N2:Eu) and yellow phosphor. This segmentation allows each phosphor combination to be optimized independently for its specific blue LED wavelength, simplifying the overall manufacturing process while achieving CRI≥90.
3Adaptability or versatility
If the blue LED dominant wavelength is shifted to improve color temperature tuning, then the CCT range expands, but the CRI decreases in the 5000-6000K range
Solution Approach 1:
The patent segments the blue LED emission into two distinct wavelength ranges: first blue LED emitting at 445-465nm and second blue LED emitting at 460-480nm. This segmentation creates overlapping spectral regions that can be independently controlled to achieve any CCT from 2500K to 8000K while maintaining CRI≥90. The overlapping regions provide spectral redundancy that compensates for CRI losses that would occur with single-wavelength approaches.
Solution Approach 2:
The patent utilizes parameter changes in the blue LED dominant wavelengths (445-465nm and 460-480nm) combined with specific phosphor materials to achieve continuous CCT tuning from 2500K to 8000K. By adjusting the relative intensities of the two blue LEDs and their associated phosphors, the system can precisely control both CCT and CRI, overcoming the limitation of fixed CCT in conventional single-blue-LED systems.
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 enables the production of white light with CRI values ≥90 across the desired color temperature range, enhancing color rendition and tunability while maintaining system complexity and production simplicity.
Implementation Method 1
a color conversion means, wherein the dominant wavelength of the first blue LED is between 451nm and 457nm... and a color conversion means is applied at least to one of the blue LEDs
Implementation Method 2
color conversion means, such as inorganic phosphors or quantum dots
Implementation Method 3
at least two blue LEDs, a red LED, mounted onto a substrate
Data Source
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AI summary
A white light emitting LED-module, comprising: - at least two blue LEDs, - a red LED, mounted onto a substrate and a color conversion means, wherein the dominant wavelength of the first blue LED is between 451nm and 457nm, preferably between 452.5nm and 455nm, and the dominant wavelength of the red LED is between 610 and 620nm, preferably between 612 and 618nm, more preferably between 615nm and 617.5nm, and the color conversion means is applied at least to one of the blue LEDs.