Wavelength Conversion Member Phosphor Distribution Thermal Management
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Solution Overview
Problem
Existing vehicular lamp units using semiconductor light-emitting elements and phosphors face inefficiencies in light emission and color adjustment due to thermal management and phosphor distribution limitations.
Innovation Solution
A wavelength conversion member with a substrate and a wavelength conversion layer containing first and second phosphors, where the second phosphor has higher thermal conductivity and a larger volume, is used to improve light emission efficiency and adjust emission color by optimizing phosphor distribution and thermal conductivity within the layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a phosphor layer is used for wavelength conversion, then light emission efficiency is improved, but temperature rise occurs due to thermal accumulation
Solution Approach 1:
The patent divides the phosphor layer into multiple regions with different phosphor materials and concentrations. The first region (closer to substrate) contains phosphor with higher thermal conductivity to dissipate heat, while the second region (farther from substrate) contains phosphor optimized for wavelength conversion efficiency. This local differentiation resolves the contradiction by assigning different functional priorities to different spatial zones within the same layer.
2Productivity
If phosphor volume is increased to improve wavelength conversion, then conversion efficiency is improved, but thermal management becomes difficult
Solution Approach 1:
The patent segments the phosphor layer into multiple distinct regions with different phosphor compositions and volumes. The first region uses phosphor with higher thermal conductivity to handle heat dissipation, while the second region uses phosphor with larger volume for enhanced wavelength conversion. This segmentation allows the system to achieve both high conversion efficiency and effective thermal management simultaneously.
3Illumination intensity
If phosphor distribution is optimized for emission color, then color accuracy is improved, but light emission efficiency decreases
Solution Approach 1:
The patent applies different phosphor materials and distribution patterns in different regions of the layer. The first region (near substrate) uses phosphor optimized for thermal management, while the second region (farther from substrate) uses phosphor optimized for specific wavelength conversion and color emission. This local quality differentiation allows each region to excel at its primary function without compromising the other.
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 enhances light emission efficiency and allows for adjustable color output by efficiently conducting heat and optimizing the conversion of excitation light to longer wavelengths, suppressing temperature rise and improving wavelength conversion efficiency.
Implementation Method 1
The second phosphor has a higher thermal conductivity than the first phosphor
Implementation Method 2
a first phosphor that emits first light having longer wavelengths than excitation light, and a second phosphor that emits second light having longer wavelengths than the excitation light
Data Source
AI summary
A wavelength conversion member comprises: a substrate; and a wavelength conversion layer. The wavelength conversion layer contains a first phosphor and a second phosphor. The second phosphor has a higher thermal conductivity than the first phosphor. In the wavelength conversion layer, a volume of the second phosphor is larger than a volume of the first phosphor. The wavelength conversion layer includes a first portion and a second portion. The first portion is located closer to the substrate than the second portion, and is in direct contact with the second portion. Thicknesses of the first portion and the second portion are equal to each other. A volume V11 of the first phosphor in the first portion, a volume V12 of the second phosphor in the first portion, a volume V21 of the first phosphor in the second portion, and a volume V22 of the second phosphor in the second portion satisfy V11/V12<V21/V22.