Dual Phosphor Wheel Cooling Layout for Compact Image Projection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image projection apparatuses using a pair of laser diodes and phosphors face challenges in efficiently converting excitation light to fluorescent light due to temperature-related inefficiencies, necessitating cooling mechanisms that can complicate the design and increase size.
Innovation Solution
A light source module with a pair of phosphor wheels, each sealed in a separate cooling casing with airflow circulation paths, and an optical system that guides and combines fluorescent light, allowing for compact design by aligning airflow paths parallel or orthogonal to the optical axis, reducing dead space and enhancing heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a pair of phosphor wheels are used to increase radiation intensity, then the light output is improved, but the temperature management becomes more complex and the device size increases
Solution Approach 1:
The patent divides the cooling system into separate cooling casings for each phosphor wheel, with each casing having its own airflow circulation path. This segmentation allows independent temperature control of each phosphor wheel, managing the thermal load from multiple light sources without requiring a complex unified cooling system.
Solution Approach 2:
The patent positions the airflow circulation paths in directions parallel or orthogonal to the optical axis of the combined fluorescent light. This spatial arrangement allows the cooling mechanisms to operate in dimensions that do not interfere with the optical path, reducing device complexity while maintaining effective heat dissipation.
2Use of energy by moving object
If phosphor temperature is reduced to improve conversion efficiency, then the conversion efficiency from excitation light to fluorescent light is improved, but additional cooling mechanisms are required
Solution Approach 1:
The patent implements self-service cooling by creating airflow circulation paths within each cooling casing that enable passive or semi-passive heat dissipation. The airflow paths are designed to naturally circulate air through the phosphor wheel housing, reducing the need for complex active cooling mechanisms while maintaining low phosphor temperatures for high conversion efficiency.
3Temperature
If separate cooling casings are used for each phosphor wheel, then heat dissipation is improved, but the device size increases
Solution Approach 1:
The patent combines multiple functions within each cooling casing: the casing simultaneously serves as a structural housing for the phosphor wheel, a thermal management component with integrated airflow paths, and a spatial organizer that positions cooling elements relative to the optical axis. This merging of functions improves heat dissipation without proportionally increasing device volume.
4Volume of moving object
If airflow paths are aligned parallel or orthogonal to the optical axis, then dead space is reduced and compact design is achieved, but the cooling path design becomes more constrained
Solution Approach 1:
The patent employs asymmetric positioning of the airflow circulation paths relative to the optical axis, with paths arranged in directions parallel or orthogonal to it. This asymmetric design efficiently utilizes available space, minimizing dead space while maintaining effective cooling, without requiring overly complex airflow path configurations.
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 achieves efficient conversion of excitation light to fluorescent light while minimizing the apparatus size and improving thermal management, enabling a compact and efficient image projection system.
Implementation Method 1
The excitation light is converted into fluorescent light in the light source module
Implementation Method 2
each one of the first airflow circulation path of the first cooling casing and the second airflow circulation path of the second cooling casing has an axis
Data Source
AI summary
An image projection apparatus includes a light source module including a light source to emit excitation light, a pair of phosphor wheels, a light mixing element, an optical system to guide the excitation light emitted from the light source to the pair of phosphor wheels, and combine a pair of fluorescent lights emitted from the pair of phosphor wheels and guide combined fluorescent light to the light mixing element, an optical casing hermetically sealing the optical system, a first cooling casing hermetically sealing one of the phosphor wheels and having a first airflow circulation path, and a second cooling casing hermetically sealing another one of the pair of phosphor wheels and having a second airflow circulation path, an optical modulation element to modulate the light emitted from the light mixing element, and a projection optical system to project the light modulated by the optical modulation element onto a display device.