Phosphor Wheel Parallel Surfaces Reduce Etendue
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Solution Overview
Problem
Phosphor wheels with reflecting or transmitting surfaces experience high power density from excitation light, leading to accelerated deterioration and reduced lifespan, despite the use of resistant materials, which also increase costs.
Innovation Solution
A phosphor wheel design featuring a phosphor-supporting surface and a reflecting surface, both parallel and spaced apart, to reduce the etendue of excitation light and distribute the load on optical components, with a light-emitting unit that includes a mixing optical system and a lens to form a focal point on the phosphor, enhancing light efficiency and longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the area of irradiation of LD light on the phosphor is reduced to decrease etendue and improve light efficiency, then luminance and light utilization efficiency are improved, but the power density becomes extremely high causing accelerated deterioration of optical components and reduced usable life
Solution Approach 1:
The phosphor wheel is segmented into multiple phosphor layers (yellow phosphor layer and red phosphor layer) stacked in the optical path. This segmentation allows the excitation light to be distributed across multiple phosphor conversion interfaces, reducing the power density at any single location while maintaining high light conversion efficiency and decreasing etendue.
Solution Approach 2:
The invention transitions from a single-plane phosphor configuration to a multi-layer stacked structure in the optical path direction. By adding the dimension of layer stacking, the excitation light energy is distributed across multiple interfaces (yellow phosphor layer and red phosphor layer), reducing the load on individual optical components while maintaining efficient light conversion.
2Reliability
If resistant substrate materials and coating agents are used to protect optical components from high power density, then the durability is improved, but the cost increases
Solution Approach 1:
The invention converts the harmful high power density concentrated on a single phosphor layer into a beneficial distributed load across multiple phosphor layers. By stacking yellow and red phosphor layers, the excitation light energy is naturally distributed, transforming the harmful concentration effect into a beneficial spreading effect that protects optical components without requiring expensive resistant materials.
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 configuration increases luminance, extends the phosphor wheel's lifespan, and improves reliability by reducing the load on optical components and enhancing light utilization efficiency, resulting in improved image quality and reduced cooling requirements.
Implementation Method 1
phosphor that emits fluorescent light in response to incident light
Implementation Method 2
reflecting surface that reflects the incident light
Data Source
AI summary
A phosphor wheel has a phosphor-supporting surface on which is formed a phosphor that generates fluorescent light in response to the incidence of light; and a reflecting surface that reflects the incident light, the phosphor-supporting surface and the reflecting surface being formed both to be parallel to each other to have a distance between them in the perpendicular direction of each surface.