Scattering Reflective Substrate for Wavelength Conversion
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Solution Overview
Problem
Conventional reflection type wavelength conversion devices experience a significant decrease in light output efficiency when the power of the excitation light increases due to oxidation of high reflective layers, leading to reduced reflectivity and heat dissipation issues.
Innovation Solution
The use of a scattering reflective substrate with white porous ceramic or scattering materials, such as oxides, replaces mirror reflection to maintain high reflectivity and light utilization efficiency, even under high temperatures, by scattering and reflecting light without absorbing it, thus avoiding oxidation-related losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a silver plating layer is used to achieve high reflectivity, then the reflectivity is improved (up to 99%), but the device becomes susceptible to oxidation at high temperatures, causing reflectivity to decrease significantly
Solution Approach 1:
The patent replaces the expensive silver plating layer with a cheap white scattering material layer that does not oxidize. The white scattering material (such as TiO2, SiO2, or BaSO4) provides sufficient scattering reflection without the oxidation vulnerability of silver, effectively using a lower-cost, more stable material to replace the vulnerable high-performance material.
Solution Approach 2:
The patent employs a white scattering material layer with scattering particles distributed within a transparent resin matrix. The scattering particles create multiple light scattering paths, providing high reflectivity through scattering mechanisms rather than mirror reflection, while the material structure remains stable at high temperatures.
2Productivity
If the power of excitation light is increased to improve light output, then the productivity is improved, but the heat generation increases causing oxidation and reducing light output efficiency
Solution Approach 1:
The patent converts the harmful effect of high temperature into a beneficial outcome by using temperature-stable white scattering materials that do not oxidize. The high temperature environment, which would normally cause silver oxidation and performance degradation, is instead accommodated by materials specifically selected for their thermal stability, turning the thermal challenge into an opportunity to use more robust materials.
Solution Approach 2:
The patent uses a composite structure consisting of white scattering particles (such as TiO2, SiO2, or BaSO4) dispersed in a transparent resin matrix. This composite material combines the scattering properties of the particles with the transparency and structural integrity of the resin, creating a layer that provides both high reflectivity and thermal stability.
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 maintains high light utilization efficiency and temperature resistance, preventing the decrease in reflectivity associated with oxidation, and facilitates effective heat dissipation in high-power light emitting devices.
Implementation Method 1
the scattering reflective substrate including a white porous ceramic or a white scattering material, the white scattering material being a salt or an oxide, the white porous ceramic or white scattering material scattering a light incident on it
Implementation Method 2
the wavelength conversion layer absorbs the excitation light to generate a converted light, and outputs the converted light or a mixed light of the converted light and the excitation light
Data Source
AI summary
Disclosed are a wavelength conversion device, a light-emitting device and a projection system, comprising a wavelength conversion layer having a first surface and a second surface opposite each other. The first surface receives an excitation light. The wavelength conversion layer absorbs the excitation to produce a converted light and emits the converted light or the mixture of the converted light and the excitation light from the first surface and the second surface. A scattering reflective substrate is stacked with the wavelength conversion layer and includes a white porous ceramic or a white scattering material for scattering the incident light. The scattering reflective substrate includes a third surface facing the second surface and scatters at least a part of the incident light on the third surface and then emits all the light from the third surface to the second surface.