Phosphor Conversion Layer With Light Passages for White Light Control

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Solution Overview

Problem

Existing white light sources using blue light and yellow phosphor face challenges in maintaining consistent color temperature and color rendering due to interrelated device parameters, leading to difficulties in manufacturing white light devices with varying characteristics, and require complex setups or additional light sources to achieve desired outputs.

Innovation Solution

A light conversion layer with phosphor and light passages that allows short wavelength light to pass through, mixing with converted light to create white light, where the thickness of the layer is optimized to control the blue/yellow ratio and include light scattering particles for improved mixing, and can be applied to substrates or phosphor wheels for efficient light distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a yellow phosphor layer is used to convert blue light, then white light with desired color temperature can be created, but the thickness of the phosphor layer must be precisely controlled to maintain consistent color temperature and color rendering

Engineering Contradiction:
Improvecolor temperature consistencyVSAvoidphosphor layer thickness control
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The phosphor layer is segmented into multiple layers with different phosphor materials or characteristics. This segmentation allows each layer to contribute differently to the overall light conversion, providing independent control over color temperature and color rendering without requiring extremely precise control of a single thick layer's thickness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the phosphor layer or different layers within the conversion component have locally optimized properties. By varying phosphor composition, thickness, or distribution in different zones, the system achieves consistent color output while reducing sensitivity to overall thickness variations during manufacturing.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If additional blue light sources are added to mix with yellow phosphor light, then desired white light characteristics can be achieved, but device complexity increases

Engineering Contradiction:
Improvewhite light qualityVSAvoidnumber of light sources
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

Instead of adding more light sources, the invention achieves desired white light characteristics by changing parameters of the phosphor conversion process itself - such as phosphor material composition, layer thickness, particle size distribution, or excitation wavelength - to control the ratio of converted yellow light to remaining blue light, thereby adjusting color temperature and quality without additional LEDs or lasers.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the phosphor layer thickness is increased to convert more blue light, then more yellow light is produced, but control over the blue/yellow ratio becomes difficult

Engineering Contradiction:
Improveyellow light outputVSAvoidblue/yellow ratio control
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The system incorporates adjustable or variable parameters that allow dynamic control of the blue/yellow ratio. This may include variable thickness layers, adjustable phosphor concentration, or configurable excitation conditions that enable easy tuning of the output color mixture without being constrained by a fixed thick phosphor layer.

Inventive Principle:
Principle #15Dynamics

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

This approach enables flexible control over the blue/yellow ratio and color temperature, reducing complexity and cost by using a single light source, while maintaining efficient light mixing and distribution, thus producing consistent and high-quality white light across different manufacturing runs.

Implementation Method 1

a phosphor effective to convert the short wavelength light to converted light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

The light transmissive substrate comprises light scattering particles

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP3803509B1White light phosphor device
Publication Date: 2024.12.18 MATERION CORP
  • EP3803509B1 patent drawingFigure 1
  • EP3803509B1 patent drawingFigure 2
  • EP3803509B1 patent drawingFigure 3

AI summary

A white light source includes a light source and a phosphor conversion component. The light source emits short wavelength light peaked at a peak wavelength of 570 nanometers or shorter. The phosphor conversion component includes a light conversion layer comprising a phosphor effective to convert the short wavelength light to converted light. The light conversion layer includes light passages comprising openings or passage material that does not comprise the phosphor and is light transmissive for the short wavelength light. The light source is disposed respective to the phosphor conversion component so as to illuminate the light conversion layer with the emitted short wavelength light and to pass the short wavelength light through the light passages.