Sapphire Plate Light Source Device Thermal Stress Management

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Solution Overview

Problem

In light source devices using wavelength conversion materials, increased light output leads to higher heating values, causing potential deterioration and damage due to temperature differences between heated regions and outer areas, which existing technologies fail to adequately address.

Innovation Solution

A light source device incorporating a sapphire plate with specific surface orientations and angles relative to the c-axis, combined with a light guide member, to manage heat dissipation and reduce thermal stress by dividing excitation light into normal and abnormal components, thereby minimizing performance degradation and damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the amount of light is increased, then the light output is improved, but the heating value of the wavelength conversion material increases causing deterioration and damage

Engineering Contradiction:

Improvelight outputVSAvoidheat damage

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating different temperature zones within the wavelength conversion material through controlled light irradiation patterns. By varying the light intensity distribution locally, the patent achieves high overall light output while maintaining lower temperatures in critical regions, preventing heat-induced deterioration and damage.

Inventive Principle:

Principle #3Local quality

2Illumination intensity

If the amount of light is increased, then the light output is improved, but stress caused by temperature difference between heated part and outer region damages the wavelength conversion material

Engineering Contradiction:

Improvelight outputVSAvoidresistance to thermal stress

Core Design Contradiction:

Illumination intensityVSStrength

Solution Approach 1:

The patent employs dynamics by continuously adjusting the light irradiation pattern and intensity distribution in response to real-time temperature measurements. This dynamic control allows the system to maintain optimal light output while actively managing temperature gradients, preventing excessive thermal stress that could damage the wavelength conversion material.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by monitoring temperature distribution within the wavelength conversion material and using this information to adjust the light irradiation pattern. This closed-loop control ensures that light output is maximized while temperature differences remain within safe limits, preventing thermal stress damage.

Inventive Principle:

Principle #23Feedback

3Device complexity

If conventional light source configurations are used, then the device structure is simple, but heat dissipation performance is insufficient leading to wavelength conversion material deterioration

Engineering Contradiction:

Improvestructure simplicityVSAvoidresistance to heat deterioration

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent transitions from conventional planar light source configurations to a three-dimensional structured arrangement where light sources are positioned at multiple heights and angles relative to the wavelength conversion material. This dimensional change enables superior heat dissipation by distributing heat generation across multiple spatial zones while maintaining structural simplicity through modular design.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 performance degradation and damage from heat in light source devices by optimizing heat dissipation and stress management, ensuring the longevity of wavelength conversion materials even at higher light outputs.

Implementation Method 1

Sapphire has high light transmittance and thermal conductivity, which makes it a superior material for the holding plate

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

an angle between the first surface and the second surface, and a c-axis of sapphire is less than 10°, and an angle between the c-axis and an optical axis of the first excitation light is 5° or more and 75° or less

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 3

irradiating a laser beam perpendicular to the sapphire plate

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 4

generates white light directly or indirectly by converting wavelength from excitation light irradiated on a wavelength conversion material such as a fluorescent body

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS11781737B2Light source device and lighting device

Publication Date: 2023.10.10 KYOCERA CORP

AI summary

A light source device of the present disclosure includes a sapphire plate having a first surface and a second surface facing each other, a wavelength conversion material located opposite the first surface of the sapphire plate, and a first excitation light source emitting a first excitation light having directivity to the wavelength conversion material through the second surface, in which an angle between the first surface and the second surface, and a c-axis of sapphire less than 10°, and an angle between the c-axis and an optical axis of the first excitation light is 5° or more and 75° or less.