Glass Matrix Wavelength Converter for Low-Scattering Phosphor Emission
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Solution Overview
Problem
Existing wavelength conversion members using a phosphor powder dispersed in a resin matrix suffer from degradation due to heat and high-energy light, leading to reduced luminous efficiency, while fully inorganic solid members with glass matrices face issues of internal scattering and devitrification when increasing phosphor density.
Innovation Solution
A wavelength conversion member with a phosphor powder dispersed in a glass matrix having a refractive index of 1.6 or more and a liquidus temperature of 1070°C or below, optimized with specific compositions of SiO2, Al2O3, B2O3, MgO, CaO, SrO, BaO, ZnO, ZrO2, TiO2, La2O3, and controlled Li2O+Na2O+K2O content, reduces internal scattering and devitrification, enhancing luminous efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the density of phosphor powder is increased to improve luminous efficiency, then the absorption loss of light is reduced, but internal scattering of excitation light and fluorescence increases
Solution Approach 1:
The patent changes the refractive index parameter of the glass matrix (achieving 1.70 or higher through specific composition control) to reduce the refractive index difference with phosphor powder, thereby minimizing internal scattering while maintaining high phosphor density for efficient light absorption
2Reliability
If the softening point of the glass matrix is lowered to seal phosphor powder against heat, then heat resistance is improved, but internal scattering increases due to devitrification
Solution Approach 1:
The patent optimizes the chemical composition parameters of the glass matrix, specifically controlling the ratios of network formers (SiO2, B2O3) and modifiers (alkaline earth metal oxides) to achieve a balanced state where the softening point is sufficiently low for heat resistance while devitrification is suppressed through appropriate compositional proportions
3Ease of manufacture
If a resin matrix is used for the wavelength conversion member, then ease of manufacture is improved, but the resin is degraded by heat and high-energy light causing discoloration and deformation
Solution Approach 1:
The patent transitions from organic resin matrices to inorganic glass matrix composite materials, combining the advantages of inorganic materials (heat and light resistance) with the functional requirements of wavelength conversion, thereby eliminating resin degradation while maintaining manufacturability
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 proposed solution results in a wavelength conversion member with improved luminous efficiency and chemical resistance, maintaining homogeneous light emission by minimizing internal scattering and devitrification.
Implementation Method 1
the glass matrix has a refractive index (nd) of 1.6 or more... the refractive index difference from the phosphor powder is narrowed, so that internal scattering can be reduced
Implementation Method 2
a wavelength conversion member in which a phosphor powder is dispersed in a resin matrix... absorbs part of the light from the LED to convert it to a yellow light
Data Source
AI summary
Provided is a wavelength conversion member which is made of a phosphor powder dispersed in a glass matrix and has an excellent luminous efficiency. A wavelength conversion member is comprising: a phosphor powder dispersed in a glass matrix, wherein the glass matrix has a refractive index (nd) of 1.6 or more and a liquidus temperature of 1070° C. or below.