Nitridic LED UV Device with Luminescent Conversion

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Solution Overview

Problem

Existing UV radiation devices, such as Hg low-, medium-, and high-pressure discharge lamps, suffer from low lifetime due to plasma-glass and plasma-phosphor interactions, severe glass solarization, phosphor degradation, and plasma efficiency loss, as well as temperature dependence during start-up.

Innovation Solution

A UV radiation device utilizing a nitridic LED emitting UV radiation in the 200-300 nm range, combined with a luminescent material like LiLuF4:Pr or YPO4:Bi, which converts UV radiation and has a different spectral distribution, and is encapsulated with scattering particles and a polymer material like FEP for improved efficiency and longevity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If Hg discharge lamps are used for UV radiation, then UV radiation can be generated, but the lifetime is reduced due to plasma-glass interaction, glass solarization, and phosphor degradation

Engineering Contradiction:
ImprovelifetimeVSAvoidplasma-glass interaction stability
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The invention extracts and eliminates the harmful plasma-glass interaction by using a different radiation generation mechanism (LED with nitridic material) that does not rely on plasma discharge through glass, thereby removing the root cause of glass solarization and phosphor degradation while maintaining UV radiation generation capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the fundamental operating parameters from plasma-based discharge to LED electroluminescence, transforming the physical mechanism of UV generation to avoid the detrimental effects of plasma on glass and phosphor materials, thus extending device lifetime

Inventive Principle:
Principle #35Parameter changes

2Duration of action of moving object

If Hg discharge lamps are used for UV radiation, then UV radiation can be generated, but phosphor degradation occurs reducing efficiency

Engineering Contradiction:
ImprovelifetimeVSAvoidplasma efficiency loss
Core Design Contradiction:
Duration of action of moving objectVSLoss of energy

Solution Approach 1:

The invention extracts and removes the plasma-based excitation mechanism that causes phosphor degradation, replacing it with direct LED emission that can excite phosphors without the harmful effects of plasma, thereby preventing efficiency loss over time

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention employs LED components with nitridic materials that have inherently longer operational lifetimes compared to traditional Hg lamp phosphors, replacing the short-lived phosphor system with a more durable solid-state light source that maintains efficiency throughout its service life

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If Hg discharge lamps are used for UV radiation, then UV radiation can be generated, but temperature dependence affects performance especially during start-up

Engineering Contradiction:
Improvetemperature independenceVSAvoidtemperature dependence during start-up
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The invention substitutes the thermally-sensitive plasma discharge mechanism with an LED-based system that is far less sensitive to temperature variations, eliminating the need for complex thermal management during start-up and operation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the operational temperature parameters by using LED technology that maintains stable performance across a wider temperature range, particularly improving start-up characteristics by removing the thermal ignition requirements of plasma discharge

Inventive Principle:
Principle #35Parameter changes

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 provides a UV radiation device with reduced temperature dependence, no toxic components, adjustable emission spectrum, long lifetime, and high irradiance, suitable for various applications including medical treatments, air and water purification, and photochemical synthesis.

Implementation Method 1

a LED (light emitting diode) comprising a nitridic material which is arranged to emit first UV radiation in a wavelength range between 200 and 300 nm

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

a luminescent material configured to convert at least a part of the first UV radiation into second UV radiation, the first UV radiation and the second UV radiation having a different spectral distribution

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP2997108B1UV radiation device
Publication Date: 2020.02.05 SIGNIFY HOLDING BV
  • EP2997108B1 patent drawingFigure 1
  • EP2997108B1 patent drawingFigure 2~3
  • EP2997108B1 patent drawingFigure 4~5

AI summary

The invention relates to an UV radiation device, comprising an LED comprising a nitridic material which is arranged to emit first UV radiation in a wavelength range of 200 nm - 300 nm and a luminescent material doped with at least one of the following activators selected out of the group Eu2+, Ce3+, Pr3+, Nd3+, Gd3+, Tm3+, Sb3+, Tl+, Pb2+ and Bi3+, wherein the luminescent material is configured to convert at least a part of the primary UV radiation into secondary UV radiation, the primary UV radiation and the secondary UV radiation having a different spectral distribution.