Solid State Lighting Device with Multi-Wavelength Emitters
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Solution Overview
Problem
Current white LED lamps have poor color rendering index (CRI) values, particularly deficient in rendering red and green colors, leading to inaccurate color representation of objects, and are inefficient, which complicates the control circuitry and increases costs due to the need for various LEDs with different efficiencies.
Innovation Solution
A lighting device that combines solid state light emitters emitting light in specific wavelength ranges (400-480 nm, 555-585 nm, and 600-630 nm) to produce a mixture of light with high CRI Ra values and improved efficacy, achieving a color temperature within 10 MacAdam ellipses of the blackbody locus on a CIE Chromaticity Diagram.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If solid state light emitters (LEDs) are used to improve energy efficiency, then energy consumption is reduced, but color rendering index (CRI) deteriorates
Solution Approach 1:
The patent combines multiple solid state light emitters with different emission wavelengths (violet 400-450nm, blue 450-480nm, cyan 480-520nm, green 520-560nm, yellow-green 560-580nm, red 600-650nm) with phosphor materials to create a composite light source that achieves both high energy efficiency and high CRI (>90), resolving the contradiction between energy savings and color rendering quality
Solution Approach 2:
The invention uses composite phosphor materials including yellow phosphors (Y3Al5O12:Ce, Lu3Al5O12:Ce), red phosphors (CaAlSiN3:Eu, Sr2Si5N8:Eu), and green phosphors (β-SiAlON:Eu, SrSi2O2N2:Eu) combined with LED emitters to create a multi-wavelength light source that maintains high energy efficiency while achieving excellent color rendering across the visible spectrum
2Duration of action of stationary object
If solid state light emitters are used to extend lifetime, then service duration increases, but color accuracy deteriorates
Solution Approach 1:
The patent merges multiple solid state light emitters with peak wavelengths at 400-450nm, 450-480nm, 480-520nm, 520-560nm, 560-580nm, and 600-650nm together with appropriate phosphor materials to produce a combined spectrum that achieves CRI >90, maintaining color accuracy while benefiting from the 50,000-70,000 hour lifetime of solid state emitters
3Use of energy by moving object
If white LED lamps are used to improve energy efficiency, then energy consumption is reduced, but color rendering quality deteriorates, particularly in red and green ranges
Solution Approach 1:
The patent applies local quality by specifically enhancing the red (600-650nm) and green (520-560nm, 560-580nm) wavelength regions using targeted phosphor materials (CaAlSiN3:Eu for red, β-SiAlON:Eu for green) while maintaining high energy efficiency through solid state light emitters, ensuring accurate color rendering in previously deficient spectral regions
Solution Approach 2:
The invention employs composite phosphor materials including yellow phosphors (Y3Al5O12:Ce, Lu3Al5O12:Ce), red phosphors (CaAlSiN3:Eu, Sr2Si5N8:Eu), and green phosphors (β-SiAlON:Eu, SrSi2O2N2:Eu) in combination with LED emitters to create a composite light source that achieves both high energy efficiency and comprehensive color rendering coverage across the entire visible spectrum
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 achieves surprisingly high CRI Ra values while maintaining high efficacy, simplifying control circuitry and reducing costs by using a combination of LEDs and luminescent materials to produce a wide gamut of colors with acceptable color temperature.
Implementation Method 1
a lighting device that includes at least a first solid state light emitter, the at least a first solid state light emitter emitting light having a peak wavelength in a range of from 400 nm to 480 nm
Implementation Method 2
along with luminescent materials emitting light in the 555-585 nm range
Data Source
AI summary
There is provided a lighting device that comprises at least one 600-630 nm solid state light emitter and at least one light source emitting light within an area on a 1931 CIE Chromaticity Diagram defined by a first set of points having x, y coordinates of (0.32, 0.40), (0.36, 0.48), (0.43, 0.45), (0.42, 0.42), (0.36, 0.38), or a second set of points having x, y coordinates of (0.29, 0.36), (0.32, 0.35), (0.41, 0.43), (0.44, 0.49), (0.38, 0.53). Some embodiments further comprise at least a first power line. Also provided are methods that comprise illuminating at least one light source to emit light within one of the areas defined above, and illuminating at least one 600-630 nm emitter.