Phosphor Wheel Cooling via Segmented Airflow Paths

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Solution Overview

Problem

Existing phosphor wheel devices face challenges in cooling efficiency due to inefficient air flow distribution, which affects both the phosphor region and the driving source.

Innovation Solution

A wavelength conversion device is designed with a rotating plate having a first surface, a second surface, and an opening, along with a wavelength converter, a rotating body, a driving source, a suction part, and a plurality of fins and flow paths. This configuration enhances air flow circulation and cooling efficiency by directing air flows to both surfaces of the rotating plate and the driving source.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fins are provided on the rear surface side of the substrate to generate air flow, then heat radiation efficiency from the front surface is improved, but the air flow does not reach the motor sufficiently and cooling efficiency is insufficient

Engineering Contradiction:

Improvecooling efficiency of phosphor regionVSAvoidcooling efficiency of motor

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The air flow path is segmented into multiple channels: one through the first openings for the phosphor region and another through the second openings for the motor. This segmentation allows independent optimization of cooling paths for different components, enabling sufficient air flow to reach both the phosphor region and the motor simultaneously

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second openings act as intermediaries that redirect air flow from the front surface toward the motor. By providing these intermediate air flow paths, the system ensures that air reaching the motor is sufficient for effective cooling, while still maintaining the primary cooling function for the phosphor region

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If second openings are provided on the circumference away from the rotation axis, then air flow can reach the motor, but the air flow does not efficiently cool the phosphor region

Engineering Contradiction:

Improvecooling efficiency of motorVSAvoidcooling efficiency of phosphor region

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The cooling system is segmented into two functional zones: the first openings positioned closer to the rotation axis for phosphor region cooling, and the second openings positioned farther from the rotation axis for motor cooling. This spatial segmentation allows each opening type to serve its designated cooling function effectively without interfering with the other

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the substrate are assigned different cooling characteristics: the area closer to the rotation axis has first openings optimized for phosphor cooling, while the area farther from the rotation axis has second openings optimized for motor cooling. This local differentiation ensures that each component receives air flow tailored to its specific cooling requirements

Inventive Principle:

Principle #3Local quality

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 improved air flow circulation effectively cools both the wavelength converter and the driving source, enhancing the overall cooling efficiency and reducing the risk of heat transfer from the wavelength converter to the driving source.

Implementation Method 1

a wavelength converter disposed further on an outer side than the opening on the rotating plate and configured to emit converted light obtained by converting a wavelength of excitation light made incident on the wavelength converter

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Implementation Method 2

a suction part configured by combining the rotating plate and the rotating body, provided on an inner side of the opening when viewed from a side opposite to the driving source with respect to the rotating plate, and communicating with, via the opening, a space on the side opposite to the driving source with respect to the rotating plate

Methodology Applied

Scientific EffectNegative pressure generation: Pressure Gradient

Implementation Method 3

a plurality of fins respectively extending from a portion on the rotation axis side toward an outer side of the rotating plate, disposed side by side around the suction part, and rotated together with the rotating plate by the driving source

Methodology Applied

Scientific EffectForced convection: Forced Convection

Data Source

PatentUS20250044575A1Wavelength conversion device, light source device, and projector

Publication Date: 2025.02.06 SEIKO EPSON CORP

AI summary

A wavelength conversion device includes a rotating plate, a wavelength converter disposed further on the outer side than an opening in a radial direction of the rotating plate, a rotating body coupled to the rotating plate, a driving source configured to rotate the rotating plate and the rotating body centering on a rotation axis, a suction part configured by combining the rotating plate and the rotating body, provided on an inner side of the opening of the rotating plate, and communicating with, via the opening, a space on a side opposite to the driving source with respect to the rotating plate, a plurality of fins rotated together with the rotating plate, and a plurality of flow paths provided among the fins and configured to cause an air flow flowing into an inside of the suction part via the opening to flow to the outside of the rotating body.