Sparkling LED Filament Lighting Device with Embedded Particles

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Solution Overview

Problem

Current solutions for creating a sparkling effect in lighting devices are costly, cumbersome, and complex, often requiring separate installations of light sources and glittering surfaces, which limits their versatility, efficiency, and cost-effectiveness.

Innovation Solution

A solid state lighting device featuring a light-transmissive LED filament with a luminescent encapsulant and light-transmissive particles, where the particles' average longest dimension extension is between 0.4 to 1.5 times the encapsulant thickness, allowing for wavelength conversion and scattering to create a sparkling visual effect without external patterned layers or gratings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional light sources with separate glittering surfaces are used, then a sparkling effect is achieved, but the device complexity and installation cost increase

Engineering Contradiction:
Improvemanufacturing complexityVSAvoidinstallation complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines the light source and glittering surface into a single integrated LED bulb structure. The LED filament is directly embedded in the glass bulb with glittering particles applied to the inner surface, eliminating the need for separate light sources and glittering surface installations. This merging approach reduces both manufacturing complexity and installation complexity while maintaining the sparkling visual effect.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If LED filaments are placed in glass bulbs to replicate incandescent appearance, then aesthetic appearance is improved, but additional lighting effects like sparkle are difficult to achieve

Engineering Contradiction:
Improvecost-effectivenessVSAvoidlighting effect versatility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent uses a composite structure combining LED filament, glass bulb, and glittering particles to achieve multiple functions. The LED filament provides energy-efficient lighting while the glittering particles add sparkling effects. This composite approach maintains cost-effectiveness by using LED technology while enhancing versatility through the addition of decorative elements that create various lighting effects.

Inventive Principle:
Principle #40Composite materials

3Illumination intensity

If light-transmissive particles are added to the encapsulant, then sparkling effect is enhanced, but material usage increases

Engineering Contradiction:
Improvesparkling effect intensityVSAvoidmaterial usage
Core Design Contradiction:
Illumination intensityVSLoss of substance

Solution Approach 1:

The patent applies glittering particles selectively to specific regions of the glass bulb interior rather than uniformly throughout. The particles are concentrated in areas where they can maximize the sparkling effect when illuminated by the LED filament, while minimizing overall material usage. This local application strategy enhances the sparkling effect intensity without proportionally increasing material consumption.

Inventive Principle:
Principle #3Local quality

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 reduces manufacturing complexity and costs, provides a self-contained sparkling effect, and enhances the aesthetic appearance of lighting devices, while minimizing material usage and environmental footprint.

Implementation Method 1

an encapsulant comprising a luminescent material, the encapsulant enclosing the light emitting surface(s) of the at least one solid state light-emitting element and being configured to at least partly convert light emitted by the solid state light-emitting element to wavelength converted light

Methodology Applied
Scientific EffectWavelength conversion: Photoluminescence

Implementation Method 2

a plurality of light-transmissive particles contained at least partly within the encapsulant... allowing for wavelength conversion and scattering to create a sparkling visual effect

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP3894745B1Lighting device with sparkle effect
Publication Date: 2023.07.19 SIGNIFY HOLDING BV
  • EP3894745B1 patent drawingFigure 1~2a
  • EP3894745B1 patent drawingFigure 2b~3c
  • EP3894745B1 patent drawingFigure 4

AI summary

A lighting device comprising solid state light-emitting elements mounted on a carrier substrate, an encapsulant comprising a luminescent material, the encapsulant enclosing the light emitting surfaces of the solid state light-emitting elements and being configured to at least partly convert light emitted by the solid state light-emitting element to wavelength converted light, and a plurality of light-transmissive particles contained at least partly within the encapsulant, the light-transmissive particles having an average longest dimension extension in the range 0.4 to 1.5 times a layer thickness of said encapsulant over the light emitting surfaces. The light-transmissive particles may disrupt the luminescent effect of the encapsulant material to create a sparkling effect.