Multi-Color Phosphor LED Layout for Uniform Tunable White Light
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Solution Overview
Problem
Existing lighting devices using discrete LED packages for tunable white light often exhibit significant color variation, leading to non-uniform light emission and increased size due to the need for secondary optics to mix colors effectively.
Innovation Solution
A lighting device design incorporating multiple LEDs with specific phosphors that absorb and emit light of different wavelengths, where all light passes through a uniform phosphor layer, creating a continuous light emitting surface for uniform appearance and reduced size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple discrete LED packages are used for tunable white light, then color temperature tuning capability is improved, but color uniformity deteriorates
Solution Approach 1:
The patent combines multiple LED packages with different color temperatures into a single integrated lighting device, using a common phosphor layer to unify the light emission. This merging approach maintains the color temperature tuning capability through selective LED activation while achieving color uniformity through the shared phosphor conversion layer.
Solution Approach 2:
The phosphor layer acts as an intermediary between the multiple LED packages and the final light output. By placing phosphor between the LEDs and the external environment, it converts and homogenizes the light from different LED sources, ensuring uniform color appearance while preserving the ability to tune overall color temperature through LED selection.
2Stability of the object's composition
If secondary optics are added to mix colors effectively, then color uniformity is improved, but device complexity increases
Solution Approach 1:
The patent extracts the color mixing function from separate secondary optics and integrates it directly into the phosphor layer that is already present in the LED package. This eliminates the need for additional optical components while maintaining effective color mixing through the phosphor's inherent light conversion properties.
Solution Approach 2:
The phosphor layer serves multiple functions simultaneously: it converts light from different LED sources, mixes the colors, and provides the final light emission. This multi-functionality eliminates the need for dedicated secondary optics, reducing device complexity while achieving color uniformity.
3Stability of the object's composition
If secondary optics are added to mix colors, then color uniformity is improved, but device size increases
Solution Approach 1:
The patent merges the color mixing function with the existing phosphor layer structure, eliminating the need for separate secondary optics components. This integration maintains compact device dimensions while achieving uniform color output through the phosphor's light conversion and mixing capabilities.
4Stability of the object's composition
If phosphor concentration is increased to improve color mixing, then color uniformity is improved, but light absorption efficiency deteriorates
Solution Approach 1:
The patent applies different phosphor concentrations in different regions or uses selective phosphor activation corresponding to different LED emissions. This localized approach optimizes color mixing in specific spectral regions while minimizing excessive absorption losses, achieving color uniformity without sacrificing overall light efficiency.
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 a uniform light source appearance with reduced size and complexity by ensuring all light passes through a single phosphor layer, enhancing color mixing and reducing the need for additional optics, while allowing for tunable white light with varying color temperature and color fidelity.
Implementation Method 1
a first phosphor disposed over the first LED and second LED and arranged to absorb a portion of the first light and in response emit a second light of a longer wavelength than the first light
Implementation Method 2
a second phosphor disposed over the second LED, the second phosphor arranged to absorb a portion of the third light and in response emit a fourth light of a longer wavelength than the third light
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A lighting device includes a first LED configured to emit a first light, a second LED configured to emit a third light, a first phosphor disposed over the first LED and second LED, and arranged to absorb a portion of the first light and in response emit a second light of a longer wavelength than the first light, and a second phosphor disposed over the second LED, the second phosphor arranged to absorb a portion of the third light and in response emit a fourth light of a longer wavelength than the third light, and the fourth light exits the second phosphor into the first phosphor, and both the second light and fourth light exit the lighting device though the first phosphor.