Phosphor-Centric White Light Color Control
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Solution Overview
Problem
Current solid state lighting technologies, such as LED-based systems, face challenges in achieving desirable color rendering indices (CRI) and tunable color temperatures due to narrow spiking in the emission spectrum, leading to less than optimal illumination of certain colors and increased complexity and cost when trying to mimic traditional lighting forms.
Innovation Solution
A phosphor-centric approach is employed, using two or more phosphors excited by separately controllable solid state sources emitting the same narrow spectrum, allowing for independent adjustment of their excitation levels to produce a combination of light spectra that results in white light with a CRI of 75 or higher and tunable color temperatures, conforming to the black body curve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LED-centric approach with multiple monochromatic LEDs is used to achieve tunable color temperature, then color control flexibility is improved, but color rendering index deteriorates due to narrow spectral spikes
Solution Approach 1:
The patent segments the white light generation into multiple independent phosphor materials, each excited by separate LED chips. This allows independent control of each phosphor's emission while collectively achieving full-spectrum white light with high CRI and tunable color temperature, resolving the contradiction between color control flexibility and color rendering quality
Solution Approach 2:
The patent uses composite phosphor materials with different emission characteristics (yellow, red, green, blue phosphors) combined in a single lighting system. This composite approach creates a complete spectrum similar to incandescent lighting while maintaining LED efficiency and tunability, achieving both high CRI and color control flexibility
2Manufacturing precision
If additional LEDs of different colors are added to improve CRI, then color rendering index is improved, but device complexity and system cost increase
Solution Approach 1:
The patent merges multiple phosphor materials into a single integrated lighting system with unified control architecture. By combining yellow, red, green, and blue phosphors excited by corresponding LED chips under one control system, it achieves high CRI without proportionally increasing system complexity, as all phosphors work together synergistically to produce complete spectrum white light
3Adaptability or versatility
If LED-based white light with color correction LEDs is used, then color temperature adjustment is achieved, but spectral uniformity deteriorates due to narrow spiking
Solution Approach 1:
The patent applies local quality by assigning specific phosphor materials to specific wavelength regions (yellow for 560-580nm, red for 610-650nm, green for 500-540nm, blue for 440-480nm). Each phosphor-LED pair is optimized for its specific spectral region, ensuring uniform spectral distribution across the entire visible range while maintaining overall color temperature adjustability through coordinated control of all pairs
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
This method enables the production of white light with improved color rendering and tunable color temperatures, meeting or exceeding the performance of traditional lighting while maintaining the advantages of solid state lighting, including high dependability and long life.
Implementation Method 1
two or more phosphors, each of which when excited is for emitting visible light of a different visible spectrum, broader than the first spectrum
Implementation Method 2
solid state sources emitting the same narrow spectrum
Data Source
AI summary
Lighting systems and devices offer dynamic control or tuning of a color characteristic, e.g. color temperature, of white light. The exemplary lighting systems and devices are used for general lighting applications that utilize solid state sources to pump remotely deployed phosphors. Two or more phosphors emit visible light of different visible spectra, and these spectra are somewhat broad, e.g. pastel, so that combinations thereof can approach white light temperatures including points along the black body curve. Independent adjustment of the intensities of electromagnetic energy emitted by the solid state sources adjusts levels of excitations of the phosphors, in order to control a color characteristic of the visible white light output of the lighting system or device.