Wavelength Conversion Member with ZnO Gap Filling
Solution Overview
Problem
Conventional wavelength conversion members in projectors face challenges in enhancing light-extraction efficiency and endurance due to limitations in phosphor distribution and heat management.
Innovation Solution
A wavelength conversion member is designed with a substrate, a reflective layer, an amorphous SiO2 layer, a metal oxide layer, and a phosphor layer where the metal oxide in the phosphor layer matches the metal oxide in the metal oxide layer, facilitating crystal growth to fill gaps between phosphors and act as a barrier for heat, thereby improving light-extraction efficiency and endurance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phosphors are capsulated by resin, then phosphors are protected and distributed, but light-extraction efficiency is reduced due to light scattering at interfaces
Solution Approach 1:
The invention extracts phosphors from resin encapsulation and places them directly on the wavelength conversion member surface. This eliminates the resin layer that causes light scattering, thereby improving light-extraction efficiency while phosphors remain protected by the metal oxide layer
Solution Approach 2:
The invention uses a composite structure where phosphors are combined with a metal oxide layer (such as ZnO) that serves multiple functions: filling gaps between phosphors, preventing phosphor deterioration, and managing heat. This composite approach maintains phosphor protection while eliminating light scattering issues
2Illumination intensity
If gaps among phosphors are filled with metal oxide, then light-extraction efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The metal oxide layer is formed before phosphors are attached to the wavelength conversion member. This preliminary formation of the metal oxide layer simplifies the overall manufacturing process by preparing the surface for phosphor placement and simultaneously filling gaps when phosphors are attached
Solution Approach 2:
The metal oxide layer serves multiple functions simultaneously: it acts as a gap-filling material to improve light extraction, provides thermal management, prevents phosphor deterioration, and serves as an adhesive layer. This multi-functionality reduces the need for separate components and simplifies manufacturing
3Illumination intensity
If metal oxide layer is added to fill gaps, then light transmission is improved, but heat management becomes more challenging
Solution Approach 1:
The invention applies metal oxide material with specific thermal properties locally at the phosphor-gaps interfaces where heat is generated. The metal oxide layer provides localized thermal management at the phosphor level while maintaining overall light transmission through the structure
Solution Approach 2:
The metal oxide layer acts as an intermediary between phosphors and the substrate, providing both optical transparency for light extraction and thermal conduction pathways. It mediates between the need for light transmission and heat dissipation by being transparent to light while conducting heat away from phosphors
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 enhances light-extraction efficiency and increases the reliability of the wavelength conversion member and associated light-emitting devices by reducing light scattering and thermal conductivity issues, leading to improved projector performance.
Implementation Method 1
forming a phosphor layer including a metal oxide between the plurality of phosphors by crystal growth of the metal oxide layer
Implementation Method 2
a reflective layer above the substrate, the reflective layer reflecting at least part of light incident from above
Implementation Method 3
a wavelength conversion member including phosphors... which emits light from a Light Emitting Diode (LED), a semiconductor Laser Diode (LD), or the like to irradiate a wavelength conversion member including phosphors to generate desired light
Data Source
AI summary
A wavelength conversion member includes a substrate, a dichroic mirror layer, an SiO2 layer, a ZnO layer, and a phosphor layer, which are sequentially stacked from the substrate. The dichroic mirror layer reflects at least part of light incident from the above. The phosphor layer includes a plurality of phosphors and ZnO between the phosphors.