Wavelength Conversion Layer Structure for Higher White Light Efficiency
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Solution Overview
Problem
Existing illumination devices have insufficient scattering angle control and light use efficiency for first-wavelength light, leading to lower light use efficiency in outputting white illumination light.
Innovation Solution
A wavelength conversion element with a substrate, reflection layer, wavelength conversion layer, and optical layer structure that includes specific reflectance properties for scattering and reflecting first-wavelength light, enhancing light use efficiency by directing scatter-reflected light away from the dichroic mirror, thereby improving the illumination device's efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light diffusion surface is provided on the wavelength conversion layer to scatter and reflect first-wavelength light, then white illumination light is formed by combining converted and scatter-reflected light, but the scattering angle is insufficient and light use efficiency is low
Solution Approach 1:
The wavelength conversion layer is divided into multiple regions with different optical properties: a first region with high reflectance for first-wavelength light and a second region with low reflectance. This segmentation allows different portions of the incident light to be directed differently, improving both scattering efficiency and light use efficiency by extracting more first-wavelength light at appropriate angles.
Solution Approach 2:
Different regions of the wavelength conversion layer are assigned different local optical qualities (reflectance properties). The first region has high reflectance to scatter light effectively, while the second region has low reflectance to allow light transmission. This local differentiation optimizes the overall light extraction efficiency while maintaining adequate scattering angles.
2Ease of operation
If the scattering structure is optimized to increase scattering angle, then light extraction is improved, but control of scatter characteristics becomes difficult
Solution Approach 1:
The wavelength conversion layer is segmented into regions with distinct optical functions. The first region is optimized for scattering with high reflectance, while the second region is optimized for transmission with low reflectance. This segmentation simplifies the control of scatter characteristics by assigning specific functions to specific regions, making the overall system easier to design and manufacture with precise angular control.
3Loss of energy
If more first-wavelength light is extracted as illumination light, then light use efficiency improves, but the balance between converted light and scatter-reflected light is disrupted
Solution Approach 1:
The wavelength conversion layer is divided into a first region that extracts first-wavelength light through scattering and a second region that allows light transmission. By carefully designing the proportion and optical properties of these regions, the system maintains a stable balance between the converted second-wavelength light and the scatter-reflected first-wavelength light, ensuring consistent white illumination quality while improving overall light use efficiency.
Solution Approach 2:
The optical parameters (reflectance, transmittance) of different regions in the wavelength conversion layer are optimized to achieve the desired balance. By adjusting these parameters in different regions, the system can extract more first-wavelength light efficiently while maintaining the proper composition ratio between first-wavelength and second-wavelength light in the final white illumination output.
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 improves light use efficiency and reduces light loss by optimizing the reflectance properties of the optical layers and structure, resulting in enhanced brightness and reduced power consumption in the illumination device, which is beneficial for projectors and other light-based applications.
Implementation Method 1
a wavelength conversion layer provided in the reflection layer and converting a light in a first wavelength range into a light in a second wavelength range different from the first wavelength range
Implementation Method 2
a structure provided in the wavelength conversion layer and scattering a part of the light in the first wavelength range
Implementation Method 3
an optical layer provided in the structure, reflecting a part of the light in the first wavelength range, transmitting another part of the light in the first wavelength range
Implementation Method 4
transmitting the light in the second wavelength range
Data Source
AI summary
A wavelength conversion element includes a substrate, reflection layer on the substrate, wavelength conversion layer in the reflection layer and converting a light in a first wavelength range into a light in a second wavelength range, structure in the wavelength conversion layer and scattering a part of the light in the first wavelength range, and optical layer in the structure, reflecting a part of the light in the first wavelength range, transmitting another part of the light in the first wavelength range, and transmitting the light in the second wavelength range. The structure includes a first structure portion, second structure portion, and planar portion between the first and second structure portions, the optical layers in the first and second structure portions have first reflectance for the light in the first wavelength range, and the optical layer in the planar portion has second reflectance.