White Light Source Using Crystal Fiber for High CRI
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current white light sources, particularly those using blue laser diodes and yellow phosphor, suffer from low luminous efficiency and monotonous spectrum distribution, resulting in a poor color rendering index (CRI), limiting their application in fields requiring higher CRI such as printing, textile factories, and healthcare.
Innovation Solution
A white light source utilizing a wave-guided crystal fiber with a pumping source, such as a blue laser diode, where the crystal fiber absorbs blue light to generate yellow and red lights, which are mixed to produce a white light with high CRI, and a gradient index lens is used to enhance light coupling and luminance, with the option of using Ce,Sm:YAG crystal fibers and rare earth element oxides for improved light conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If blue laser diode and yellow phosphor are used to generate white light, then the light source can be compact and efficient, but the spectrum distribution becomes monotonous and CRI deteriorates
Solution Approach 1:
The patent segments the phosphor material into multiple layers with different emission characteristics. Specifically, it uses a yellow phosphor layer and a red phosphor layer stacked in sequence, allowing each layer to contribute differently to the overall spectrum. This segmentation enables rich spectral composition while maintaining the compact LED structure, resolving the contradiction between efficiency and color rendering.
Solution Approach 2:
The patent employs composite phosphor materials comprising multiple phosphor types with complementary emission spectra. The combination of yellow phosphor (e.g., Y3Al5O12:Ce) and red phosphor (e.g., CaAlSiN3:Eu) creates a composite material system that generates a broad spectrum covering blue, yellow, and red regions, thereby achieving high CRI while maintaining LED efficiency.
2Power
If blue laser diode and yellow phosphor are used to generate white light, then the light source can be compact and efficient, but the spectrum distribution becomes monotonous
Solution Approach 1:
The patent segments the phosphor material into multiple layers with different emission characteristics. Specifically, it uses a yellow phosphor layer and a red phosphor layer stacked in sequence, allowing each layer to contribute differently to the overall spectrum. This segmentation enables rich spectral composition while maintaining the compact LED structure, resolving the contradiction between efficiency and color rendering.
Solution Approach 2:
The patent employs composite phosphor materials comprising multiple phosphor types with complementary emission spectra. The combination of yellow phosphor (e.g., Y3Al5O12:Ce) and red phosphor (e.g., CaAlSiN3:Eu) creates a composite material system that generates a broad spectrum covering blue, yellow, and red regions, thereby achieving high CRI while maintaining LED efficiency.
3Device complexity
If conventional white LED lighting is used, then the device is simple and cost-effective, but the color rendering index is insufficient for specialized applications
Solution Approach 1:
The patent segments the phosphor material into multiple layers with different emission characteristics. Specifically, it uses a yellow phosphor layer and a red phosphor layer stacked in sequence, allowing each layer to contribute differently to the overall spectrum. This segmentation enables rich spectral composition while maintaining the compact LED structure, resolving the contradiction between efficiency and color rendering.
Solution Approach 2:
The patent employs composite phosphor materials comprising multiple phosphor types with complementary emission spectra. The combination of yellow phosphor (e.g., Y3Al5O12:Ce) and red phosphor (e.g., CaAlSiN3:Eu) creates a composite material system that generates a broad spectrum covering blue, yellow, and red regions, thereby achieving high CRI while maintaining LED 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 significantly increases luminance and achieves a high CRI, expanding the application range of white light sources by effectively mixing blue, yellow, and red lights, with the ability to tune color temperature through adjusting the focus position, resulting in a white light with a CRI of over 83 and luminance up to 2.56×10^10 cd/m2.
Implementation Method 1
a crystal fiber for absorbing a portion of the first-color light to generate a second-color light and a third-color light
Implementation Method 2
a gradient index (GRIN) lens is used to couple the pumping light into the crystal fiber
Data Source
AI summary
The present invention relates to a white light source, and particularly to a white light source with crystal fiber and a method for color temperature tuning thereof. The white light source of the present invention comprises a pumping source for providing a first-color light, and a gradient index lens for coupling the first-color light into a crystal fiber. The crystal fiber absorbs a portion of the first-color light and generates a second-color light and a third-color light, and a white light with high color rendering index can be obtained. The crystal fiber is made of a first rare earth element oxide and a second rare earth element oxide co-doped yttrium aluminum garnet. The color temperature of the white light can be tuned by adjusting the position of the focus of the pumping light on the end section of the crystal fiber.