Light Guide with Metal Strip for LED Heat Dissipation

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Solution Overview

Problem

Solid state lighting devices, such as LEDs, face challenges with heat management and limited light emitting area compared to traditional light sources, requiring innovative solutions for efficient heat dissipation and increased light output.

Innovation Solution

A lighting device design featuring a light guide with a metal strip arranged along its edge, where the solid state light source is in thermal contact with the metal strip, allowing for efficient heat dissipation and increased light emitting area through total internal reflections within the light guide, providing a more omnidirectional light output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a traditional light source is replaced by a solid state light source, then energy efficiency is improved, but heat management becomes more challenging and light emitting area is reduced

Engineering Contradiction:

Improveenergy efficiencyVSAvoidheat management

Core Design Contradiction:

Use of energy by moving objectVSTemperature

Solution Approach 1:

The light guide serves dual functions: optical guidance for light emission and thermal conduction for heat dissipation. By making the light guide thermally conductive and extending it beyond the light source area, the invention simultaneously addresses light distribution and heat management, eliminating the need for separate heat sink components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges the optical function (light guidance) and thermal function (heat dissipation) into a single integrated component. The light guide structure combines both light transmission properties and thermal conduction properties, consolidating multiple functions into one element to simplify the overall device architecture.

Inventive Principle:

Principle #5Merging (Combining)

2Use of energy by moving object

If a solid state light source is used, then energy consumption is reduced, but the light emitting area becomes smaller compared to traditional light sources

Engineering Contradiction:

Improveenergy consumptionVSAvoidlight emitting area

Core Design Contradiction:

Use of energy by moving objectVSArea of stationary object

Solution Approach 1:

The light guide extends the light emitting area from a point source into a two-dimensional planar structure. By guiding light along the light guide and emitting it from the lateral surface, the invention transforms the light emission from a zero-dimensional point to a two-dimensional area, significantly increasing the effective light emitting surface.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The light guide is divided into multiple emission segments along its length. Different portions of the light guide can emit light independently, creating multiple light emitting zones that collectively provide a larger total emitting area compared to a single point source.

Inventive Principle:

Principle #1Segmentation

3Temperature

If heat dissipation structures are added to manage thermal output, then temperature control is improved, but device complexity increases

Engineering Contradiction:

Improvetemperature controlVSAvoiddevice complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention extracts the heat dissipation function from separate thermal management components and integrates it into the light guide itself. By removing the need for additional heat sink structures and making the light guide thermally conductive, the design simplifies the overall device while maintaining effective temperature control.

Inventive Principle:

Principle #2Taking out (Extraction)

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 design enhances heat management and light distribution, reducing the need for additional heat sinks and improving the overall efficiency of the lighting device, while maintaining a compact form factor.

Implementation Method 1

light emitted by the solid state light source propagates within the light guide (e.g. including one or more total internal reflections within the light guide) before exiting the light guide

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The metal strip is arranged in thermal contact with the surface. The solid state light source is arranged in thermal contact with the metal strip

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3325873B1Lighting device with light guide

Publication Date: 2019.09.18 SIGNIFY HOLDING BV

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AI summary

A lighting device (100, 500) is provided which comprises a light guide (110, 510), a metal strip (120, 520), a solid state light source (130, 530) and a base (160, 170, 540, 550) for mounting the lighting device. The base includes an electrical interface. The light guide extends along a plane (140). The metal strip extends at least partly around the light guide along a surface (111) of the light guide. The metal strip is arranged in thermal contact with the surface of the light guide. The solid state light source is arranged in thermal contact with the metal strip and is arranged to emit light into the light guide. The light guide serves to increase a light emitting area of the lighting device and to dissipate heat. The metal strip allows heat generated by the solid state light source to be transferred to the light guide.