Phosphor Module Protrusion Reduces Yellow Ring and Heat

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Solution Overview

Problem

Conventional phosphor modules in laser light sources suffer from thermal quenching and the generation of a yellow ring due to the scattering of yellow light, which reduces luminance and increases the area of the phosphor layer, making it difficult to control particle size and pore of ceramic phosphors, leading to inefficient heat dissipation and light output.

Innovation Solution

A phosphor module with a heat radiator, a phosphor layer, and a reflective layer, where the phosphor layer includes a protrusion exposed through the reflective layer, and an adhesive layer between the heat radiator and phosphor layer to enhance heat dissipation and direct light reflection, minimizing the yellow ring and increasing luminance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the phosphor layer area is increased to reduce yellow ring, then the yellow ring area is reduced, but the heat dissipation efficiency deteriorates

Engineering Contradiction:
Improveyellow ring areaVSAvoidheat dissipation efficiency
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The phosphor layer is segmented into a protrusion portion and a recess portion, creating a three-dimensional structure that increases surface area for light emission while maintaining efficient heat contact with the heat radiator. This segmentation allows the phosphor layer to reduce yellow ring area through controlled light emission geometry while preserving heat dissipation pathways.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The phosphor layer transitions from a flat two-dimensional structure to a three-dimensional structure with protrusions and recesses. This dimensional change enables the phosphor layer to control light emission directionality (reducing yellow ring) while maintaining adequate heat dissipation surface area through vertical structuring.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If the phosphor layer area is decreased to improve heat dissipation, then the heat dissipation efficiency is improved, but the luminance decreases

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidluminance
Core Design Contradiction:
TemperatureVSIllumination intensity

Solution Approach 1:

The phosphor layer is divided into protrusion portions that emit light and recess portions that facilitate heat dissipation. This segmentation allows the structure to maintain high luminance through optimized light-emitting surfaces while ensuring efficient heat removal through the recess areas that contact the heat radiator.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the phosphor layer are given different functions: the protrusion portions are optimized for light emission (higher luminance), while the recess portions are optimized for heat dissipation (better thermal contact). This local differentiation allows simultaneous achievement of high luminance and effective heat management.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If conventional phosphor structures are used, then the manufacturing process is simple, but thermal quenching occurs during optical conversion

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidthermal quenching resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The phosphor layer is structured with protrusions and recesses that can be formed through standard semiconductor manufacturing techniques such as photolithography and etching. This segmented structure provides thermal quenching resistance by reducing heat accumulation in any single region, while remaining compatible with existing manufacturing processes.

Inventive Principle:
Principle #1Segmentation

4Illumination intensity

If the phosphor layer is made thicker to increase light output, then the luminance increases, but the yellow ring generation increases

Engineering Contradiction:
ImproveluminanceVSAvoidyellow ring area
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

Instead of increasing phosphor layer thickness uniformly in the horizontal plane, the structure utilizes vertical dimensionality with protrusions and recesses. This allows increased light output through greater phosphor material volume while controlling yellow ring generation through the geometric configuration that directs light emission preferentially forward.

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 the area of the yellow ring, improves heat dissipation, and increases the brightness of the light source by efficiently directing light and dissipating heat, while maintaining the optical conversion efficiency of the phosphor module.

Implementation Method 1

a phosphor layer (220), disposed on the heat radiator, being configured to emit light with a wavelength different from that of the light being absorbed

Methodology Applied
Scientific EffectOptical conversion: Photoluminescence

Implementation Method 2

a reflective layer (230) disposed on a surface of the phosphor layer and configured to reflect light

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

heat generated during an optical conversion in a phosphor layer may be efficiently emitted to the outside

Methodology Applied
Scientific EffectHeat dissipation: Thermal Radiation

Data Source

PatentEP3480517B1Phosphor module
Publication Date: 2021.09.22 LG ELECTRONICS INC
  • EP3480517B1 patent drawingFigure 1~2
  • EP3480517B1 patent drawingFigure 3~4
  • EP3480517B1 patent drawingFigure 5A~5B

AI summary

a phosphor module (200) for a laser light source includes a heat radiator (210), a phosphor layer (220), disposed on the heat radiator, being configured to emit light with a wavelength different from that of the light being absorbed and a reflective layer (230) disposed on a surface of the phosphor layer and configured to reflect light, wherein the phosphor layer (220) comprises a protrusion that is exposed through the reflective layer.