Phosphor Segmentation for White LED Color Rendering
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Solution Overview
Problem
Conventional white light emitting devices using blue light emitting diodes and yellow phosphors suffer from quantum deficits and reduced optical efficiency, leading to insufficient green and red color components, resulting in unnatural color display and limited applications.
Innovation Solution
A phosphor manufacturing method involving a chemical formula of aMO-bAlN-cSi3N4, where M is an alkaline earth metal, is used to create phosphors that emit green, yellow, and red light, with specific molar ratios and thermal treatment conditions to achieve desired emission spectra, and these phosphors are combined with a blue light emitting diode to produce white light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a blue light emitting diode and a yellow phosphor are combined to emit white light, then the device structure is simple and easy to manufacture, but quantum deficits occur and optical efficiency is reduced
Solution Approach 1:
The patent segments the yellow phosphor into multiple phosphors with different emission wavelengths (green, yellow, red phosphors). Each phosphor converts a portion of the blue light, reducing quantum deficits and improving overall optical efficiency while maintaining the simple LED-based structure
Solution Approach 2:
The patent uses a composite phosphor system consisting of multiple phosphor materials (green phosphor, yellow phosphor, red phosphor) combined with the blue LED. This composite approach optimizes energy conversion efficiency while maintaining ease of manufacture through conventional coating methods
2Ease of manufacture
If a blue light emitting diode and a yellow phosphor are combined to emit white light, then the device structure is simple, but green and red color components are insufficient resulting in unnatural colors
Solution Approach 1:
The patent segments the broad yellow emission into distinct green, yellow, and red phosphor components. This segmentation provides sufficient green and red color components for natural color rendering while maintaining the simple single-LED structure through multi-phosphor coating
Solution Approach 2:
The patent applies local quality by assigning specific emission characteristics to different phosphor regions. Each phosphor (green, yellow, red) provides localized color enhancement, collectively achieving superior color rendering across the entire visible spectrum
3Ease of operation
If conventional phosphors are used with blue light emitting diodes, then the device is easy to operate and inexpensive, but luminance is reduced and color rendering is poor
Solution Approach 1:
The patent employs a composite phosphor system with multiple materials optimized for different wavelength conversions. This composite structure enhances luminance and color rendering while preserving ease of operation through conventional LED driving methods and standard manufacturing processes
4Illumination intensity
If multiple phosphors with different emission wavelengths are used to improve color rendering, then color purity and rendering index are enhanced, but device complexity increases
Solution Approach 1:
The patent segments the phosphor system into discrete green, yellow, and red phosphor components that can be independently selected and optimized. This segmentation achieves superior color rendering while managing complexity through modular design and conventional multi-layer coating techniques
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 enhances color purity and rendering index of white light emitting devices, improving their suitability for various applications beyond limited fields like portable terminals and PCs by stabilizing the crystal structure and optimizing emission efficiency.
Implementation Method 1
A phosphor serves as a medium, which converts energy of an excitation source into energy of visible light
Implementation Method 2
a blue light emitting diode, which is one of light emitting devices that emit white light
Data Source
AI summary
Provided are a phosphor, a phosphor manufacturing method, and a white light emitting device. The phosphor is represented as a chemical formula of aMO-bAlN-cSi3N4, which uses light having a peak wavelength in a wavelength band of about 350 nm to about 480 nm as an excitation source to emit visible light having a peak wavelength in a wavelength band of about 480 nm to about 680 nm. (where M is one selected from alkaline earth metals (0.2≦a/(a+b)≦0.9, 0.05≦b(b+c)≦0.85, 0.4≦c/(c+a)≦0.9)).