Violet LED Lamp with Remote Phosphor Layers
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Solution Overview
Problem
Legacy LED light bulbs using blue-emitting diodes in combination with red and/or green/yellow phosphors often result in color-shifting, which is undesirable for aesthetic reasons and can lead to premature degradation of encapsulant materials due to blue light exposure, limiting their lifespan.
Innovation Solution
The use of LEDs emitting violet or red and green light in combination with remote wavelength-converting layers that absorb and emit light in specific ranges to produce a white appearance, avoiding blue-emitting LEDs and thus minimizing material degradation and enhancing aesthetic appeal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If blue-emitting LEDs are used in combination with red and/or green/yellow phosphors, then white light is produced, but color shifting occurs and encapsulant materials degrade prematurely
Solution Approach 1:
The patent extracts the blue-emitting LED component from the traditional blue LED + phosphor configuration and replaces it with violet-emitting LEDs. This extraction eliminates the harmful blue light that causes encapsulant degradation while maintaining the ability to produce white light through combination with red and green phosphors.
Solution Approach 2:
The patent changes the emission wavelength parameter of the LED from blue (around 450 nm) to violet (around 405 nm). This parameter change shifts the light source to a wavelength that does not cause encapsulant degradation, while still enabling white light production when combined with appropriate phosphors.
2Illumination intensity
If blue-emitting LEDs are used in combination with red and/or green/yellow phosphors, then white light is produced, but color shifting occurs
Solution Approach 1:
By changing the LED emission wavelength from blue to violet, the patent modifies the spectral composition parameters. This parameter change results in more stable color output because violet light combined with red and green phosphors produces a more consistent white light spectrum that maintains color stability over time and across different viewing conditions.
3Illumination intensity
If green- and/or yellow-emitting materials are used in the exterior structure, then white light is produced, but aesthetic appeal is reduced
Solution Approach 1:
The patent applies local quality by placing the wavelength-converting phosphors in specific locations (embedded in encapsulants or coating surfaces) rather than using them as exterior structural elements. This allows the white light production function to be maintained while the exterior structure maintains its traditional white or near-white appearance, preserving aesthetic appeal.
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 approach results in LED lamps that produce a stable white light with improved longevity and aesthetic appeal by using violet and red/green LEDs with remote wavelength-converting layers, reducing blue light exposure and enhancing the perceived brightness of yellow and green light.
Implementation Method 1
a first wavelength converting layer configured to absorb at least a portion of the radiation emitted by the first plurality of radiation sources
Implementation Method 2
the first wavelength converting layer having an emission wavelength ranging from about 420 nm to about 520 nm
Implementation Method 3
a first wavelength converting layer configured to absorb at least a portion of radiation emitted by the second plurality of radiation sources
Implementation Method 4
the first wavelength converting layer having an emission wavelength ranging from about 500 nm to about 750 nm
Implementation Method 5
a first wavelength converting layer disposed on the remote structural member, the first wavelength converting layer configured to absorb at least a portion of radiation emitted by the light source
Implementation Method 6
the first wavelength converting layer having an emission wavelength ranging from about 420 nm to about 520 nm
Implementation Method 7
a second wavelength converting layer disposed on the remote structural member
Implementation Method 8
the second wavelength converting layer having an emission wavelength ranging from about 490 nm to about 630 nm
Data Source
AI summary
Light emitting devices and techniques for using remote blue phosphors in LED lamps are disclosed. An LED lamp is formed by configuring a first plurality of n of radiation sources to emit radiation characterized by a first wavelength, the first wavelength being substantially violet, and configuring a second plurality of m of radiation sources to emit radiation characterized by a second wavelength, the second wavelength also being substantially violet. Aesthetically-pleasing white light is emitted as the light from the radiation sources interacts with various wavelength converting materials (e.g., deposits of red-emitting materials, deposits of yellow/green-emitting materials, etc.) including a blue-emitting remote wavelength converting layer configured to absorb at least a portion of the radiation emitted by the first plurality of radiation sources. The remote wavelength converting layer emits wavelengths ranging from about 420 nm to about 520 nm.