Dual-Phosphor High-Brightness Light Source for Spectral Stability

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Solution Overview

Problem

Existing high-power light sources based on laser pumps and pumped luminescent crystals face issues with spectral properties changing over time and with temperature, leading to undesirable variations in light output.

Innovation Solution

A light generating system comprising a first light generating device, a first luminescent material with a line absorber and emitter, and a second luminescent material with broad band emission, configured to generate light with controlled spectral properties and high intensity, using a superluminescent diode or laser as the light source.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a laser pump and luminescent crystal system is used to achieve high brightness, then the light intensity can reach up to 300 cd/mm², but the spectral properties change over time and with temperature causing instability

Engineering Contradiction:
Improvelight intensityVSAvoidspectral stability
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The system segments the luminescent conversion function into multiple independent phosphor materials (first phosphor with line emission and second phosphor with broad band emission) that work together. This segmentation allows each phosphor to contribute differently to the overall spectral output, providing redundancy and stability against spectral shifts over time and temperature variations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses a composite phosphor system combining a first phosphor material exhibiting line emission characteristics and a second phosphor material exhibiting broad band emission characteristics. This composite approach creates a hybrid luminescent system where the narrow line emission provides spectral precision while the broad band emission provides spectral stability and tolerance to environmental variations.

Inventive Principle:
Principle #40Composite materials

2Power

If a laser is used as the light source to generate high intensity light, then brightness can be improved, but the narrow emission band is sensitive to spectral changes leading to variability

Engineering Contradiction:
Improvelight powerVSAvoidspectral consistency
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The invention changes the spectral parameters of the luminescent conversion system by using phosphors with different emission bandwidths. The first phosphor converts laser light to a narrow line emission while the second phosphor converts to a broad band emission. This parameter diversification makes the overall system less sensitive to spectral changes in the laser pump, improving reliability.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If phosphor materials are arranged on or inserted in a heatsink for thermal management, then brightness can be increased, but the system complexity increases

Engineering Contradiction:
ImprovebrightnessVSAvoidsystem complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The invention merges the thermal management function with the luminescent conversion function by integrating both phosphor materials into a single heatsink structure. This consolidation approach combines multiple functions (thermal dissipation and spectral conversion) into one integrated component, reducing overall system complexity while maintaining high brightness performance.

Inventive Principle:
Principle #5Merging (Combining)

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 system provides high CRI, high intensity, and stable spectral output over time, with improved reliability and control over color point, color rendering index, and correlated color temperature.

Implementation Method 1

a first light source which is selected from the group of a superluminescent diode and a laser

Methodology Applied
Scientific EffectStimulated emission: Laser

Implementation Method 2

a first luminescent material providing a first luminescent material emission comprising a line emission at a first wavelength upon excitation with the first device light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 3

a second luminescent material providing a second luminescent material emission comprising a broad band emission upon excitation with the first device light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 4

a line absorber and line emitter luminescent material providing a first luminescent material emission comprising a line emission

Methodology Applied
Scientific EffectSelective absorption: Absorption (EM radiation)

Data Source

PatentEP4469720B1High brightness light source
Publication Date: 2025.11.26 SIGNIFY HOLDING BV
  • EP4469720B1 patent drawingFigure 1A
  • EP4469720B1 patent drawingFigure 1B~1C
  • EP4469720B1 patent drawingFigure 1D

AI summary

The invention provides in embodiments a light generating system (1000) comprising a first light generating device (100), a first luminescent material (210), and a second luminescent material (220), wherein: A) the first light generating device (110) is configured to generate first device light (111), wherein the first light generating device (110) comprises a first light source (10) selected from the group of a superluminescent diode and a laser; B) the first luminescent material (210) comprises a line absorber and line emitter luminescent material providing a first luminescent material emission (211) comprising a line emission at a first wavelength (λL,1) upon excitation with the first device light (111); C) the second luminescent material (220) comprises a broad band emitter luminescent material providing a second luminescent material emission (221) comprising a broad band emission upon excitation with the first device light (111), wherein the second luminescent material emission (221) has a second centroid wavelength (λLC,2), wherein |λL,1 - λLC,2| ≤ 20 nm; D) the first light generating device (110) is configured to pump one or more of the first luminescent material (210) and the second luminescent material (220) with the first device light (111); and E) the light generating system (1000) is configured to generate system light (1001) comprising one or more of the first luminescent material emission (211) and the second luminescent material emission (221).