Textured Lumiphoric Layer Interface for Solid State Lighting

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Solution Overview

Problem

Existing solid state lighting devices with multiple layers of wavelength conversion materials face challenges in adhesion between layers, control of optical properties, and enhancement of light extraction and color mixing.

Innovation Solution

The implementation of a lighting device with a textured interface between lumiphoric material layers, featuring outwardly protruding portions or recesses, enhances adhesion and optical control, and improves light extraction and color mixing by using a method that includes depositing a first layer with a lumiphoric material over an electrically activated emitter and forming textured features on this layer before depositing a second lumiphoric material layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple discrete layers of lumiphoric materials are used, then color mixing and optical property control are improved, but adhesion between layers deteriorates

Engineering Contradiction:

Improveoptical property controlVSAvoidadhesion between layers

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies curvature by forming protruding portions with rounded tops and curved lateral walls on the first lumiphoric material layer. These curved geometric features enhance the mechanical interlocking with the second lumiphoric material layer, thereby improving adhesion while maintaining the multiple-layer structure for optical property control

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent creates localized adhesive features by forming discrete protruding portions at specific locations on the first layer rather than uniformly modifying the entire surface. This localized modification approach improves adhesion at critical interfaces while preserving the overall optical properties of the lumiphoric material layers

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If multiple discrete layers of lumiphoric materials are used, then color mixing is improved, but light extraction deteriorates

Engineering Contradiction:

Improvecolor mixingVSAvoidlight extraction

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The curved lateral walls and rounded tops of the protruding portions serve as light-trapping features that reduce total internal reflection at the layer interfaces. This curved geometry allows light to undergo multiple internal reflections and eventually escape, thereby improving light extraction efficiency while maintaining the multiple-layer structure for enhanced color mixing

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Strength

If textured interface with protruding portions is created, then adhesion between layers is improved, but device complexity increases

Engineering Contradiction:

Improveadhesion between layersVSAvoidinterface structure complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent divides the interface between layers into discrete segmented protruding portions rather than creating a continuous complex texture. Each protruding portion is a simple geometric feature with a rounded top and curved lateral wall, making the overall structure easier to manufacture while still providing sufficient adhesion improvement through mechanical interlocking

Inventive Principle:

Principle #1Segmentation

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 leads to improved adhesion, control over optical properties, and increased light extraction, allowing for better color mixing and tailored lighting performance.

Implementation Method 1

a textured interface between the first layer and the second layer, the textured interface including at least one outwardly protruding portion... to enhance adhesion, control optical properties, and improve light extraction and color mixing

Methodology Applied

Scientific EffectMechanical interlocking: Mechanical Fastener

Implementation Method 2

a textured interface between the first layer and the second layer... to improve light extraction and color mixing

Methodology Applied

Scientific EffectLight scattering: Scattering

Implementation Method 3

a first layer that includes a first lumiphoric material and a second layer that includes a second lumiphoric material, and including a textured interface between the first layer and the second layer

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentUS8957580B2Lighting device including multiple wavelength conversion material layers

Publication Date: 2015.02.17 CREELED INC

AI summary

A lighting device includes an electrically activated emitter, a first layer that contains a first lumiphoric material, and a second layer that contains a second lumiphoric material, with a textured interface between the first layer and the second layer. Additional lumiphoric material layers, spacer layers, and/or encapsulant layers may be provided. Multiple textured interfaces may be provided. Textured interfaces may be arranged as lenses, including Fresnel lenses.