Wavelength Conversion Element Reducing Etendue via Segmentation
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Solution Overview
Problem
Existing light source devices for projectors face challenges in reducing etendue while preventing an increase in light density of excitation light, which leads to decreased fluorescence conversion efficiency.
Innovation Solution
A wavelength conversion element with a larger light incident surface area compared to the excitation light incident area, utilizing a substrate and optical members to transmit and reflect light efficiently, and an opening formed by these components to emit converted light, thereby reducing etendue without increasing light density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the incident area of excitation light on the phosphor is reduced, then the etendue of the fluorescence is reduced, but the light density of the excitation light increases and fluorescence conversion efficiency decreases
Solution Approach 1:
The patent segments the optical path into distinct functional zones: a large-area light incident surface for receiving excitation light, a conversion layer for wavelength transformation, and a small-area opening for emitting converted light. This spatial segmentation allows the system to maintain large input area while achieving small output etendue, resolving the contradiction between reducing etendue and maintaining conversion efficiency
Solution Approach 2:
The patent utilizes three-dimensional spatial arrangement by positioning the conversion layer between the incident surface and the emission opening. The light travels through the conversion layer in the depth dimension, allowing the incident area (in the lateral plane) to be larger than the opening area without compromising light collection efficiency. This dimensional transition enables etendue reduction while maintaining adequate light density for efficient conversion
2Area of stationary object
If the incident area of excitation light on the phosphor is reduced, then the etendue of the fluorescence is reduced, but the light density of the excitation light increases
Solution Approach 1:
The optical system is segmented into a large-area incident surface and a small-area emission opening, with the conversion layer in between. This segmentation decouples the input area from the output area, allowing the system to accept light over a large area while emitting from a small area, thus reducing etendue without increasing light density at the conversion interface
Solution Approach 2:
The patent transitions from two-dimensional area considerations to three-dimensional volume utilization. By allowing light to propagate through the conversion layer in the depth dimension, the system can have a larger lateral incident area than the opening area, effectively reducing etendue while maintaining appropriate light density for efficient fluorescence conversion
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 effectively reduces etendue and maintains fluorescence conversion efficiency, enabling high-luminance light emission in projectors.
Implementation Method 1
a wavelength conversion layer configured to convert a first light which has a first wavelength band and is incident on the light incident surface into a second light which has a second wavelength band different from the first wavelength band
Implementation Method 2
a first optical member having a first optical layer configured to transmit the first light and reflect the second light
Implementation Method 3
a second optical member having a second optical layer configured to reflect the second light
Implementation Method 4
a third optical member having a third optical layer configured to reflect the second light
Data Source
AI summary
A wavelength conversion element includes a wavelength conversion layer having a light incident surface and converting a first light into a second light, a substrate having a support surface, a first optical member having a first optical layer transmitting the first light and reflect the second light, a second optical member having a second optical layer reflecting the second light and crossing the support surface and the first optical layer, a third optical member having a third optical layer reflecting the second light and facing the second optical layer. An opening is formed by the substrate and the first, second and third optical members. A first area of the light incident surface is larger than a second area of a light incident area. The second area is larger than a third area of the opening. The second light is emitted from the opening.