Triangular Light Guide Carrier for Headlamp Heat Dissipation

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Solution Overview

Problem

Current LED retrofit headlamps face challenges in replicating the radiation characteristics of halogen lamps, particularly in near-field and far-field luminance, and struggle with effective thermal management, leading to non-compliance with legal requirements and safety issues like excessive glare.

Innovation Solution

A lighting device with a carrier having a triangular cross-section and a protruding heat sink body, where lighting modules are mounted along the arrangement direction on a concave surface, allowing for efficient heat dissipation and optical coupling with a light guide to achieve the required radiation pattern, while minimizing crosstalk and maximizing heat dissipation volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If LED lighting modules are arranged in multi-sided configurations to replicate halogen radiation patterns, then the radiation characteristic compliance improves, but the thermal management capability deteriorates due to limited heat dissipation volume

Engineering Contradiction:
Improveradiation characteristic complianceVSAvoidheat dissipation capability
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent transitions from planar 2D heat dissipation to 3D volumetric heat dissipation by implementing a heat sink with protruding heat-dissipating surfaces that extend into the space surrounding the LED modules. This three-dimensional heat sink structure provides multiple heat dissipation pathways in different spatial directions, enabling effective thermal management while maintaining the compact multi-sided LED arrangement required for halogen-like radiation patterns.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If the light emitting area is reduced to match halogen filament dimensions, then the near-field luminance compliance improves, but the heat dissipation efficiency deteriorates due to higher power density

Engineering Contradiction:
Improvenear-field luminance complianceVSAvoidheat dissipation efficiency
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent divides the LED lighting system into multiple discrete lighting modules arranged in a multi-sided configuration. Each module contains one or more LEDs with controlled emitting areas. This segmentation allows the total light output to match halogen filament luminance characteristics while distributing the heat generation across multiple separate heat dissipation zones, preventing excessive power density at any single location.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heat sink structure extends into three-dimensional space with protruding surfaces that radiate heat in multiple directions. This volumetric approach to heat dissipation compensates for the high power density resulting from small LED emitting areas, providing sufficient thermal management capacity despite the reduced light source dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Illumination intensity

If LED modules are positioned to face outward for light emission, then the radiation pattern compliance improves, but the thermal connection quality deteriorates due to insulation requirements

Engineering Contradiction:
Improveradiation pattern complianceVSAvoidthermal connection quality
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent introduces a specially designed heat sink structure as an intermediary between the LED modules and the mounting carrier. This heat sink serves dual functions: it provides excellent thermal conduction pathways from the LED mounts while simultaneously presenting an optically transparent or reflective surface to the outward-facing LED light sources. The heat sink acts as a thermal bridge that does not interfere with the required outward light emission, resolving the conflict between thermal connection and radiation pattern compliance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enables compliance with legal radiation patterns and improved thermal management, reducing glare and enhancing safety by effectively dissipating heat and redirecting light to meet halogen-like emission standards without altering the headlamp optics.

Implementation Method 1

a heat sink body portion arranged adjacent to the at least one mounting portion

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

protrudes sidewards from the at least one mounting portion

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

at least one light guide being optically coupled to the at least one lighting module

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 4

redirecting light to meet halogen-like emission standards

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP3875838B1Lighting device with light guide
Publication Date: 2023.09.20 LUMILEDS HLDG BV
  • EP3875838B1 patent drawingFigure 1a~1b
  • EP3875838B1 patent drawingFigure 2a~2b
  • EP3875838B1 patent drawingFigure 3a

AI summary

The invention refers to a lighting device (12) comprising: a carrier (2) for at least one lighting module (4) comprising at least one mounting portion (6) for receiving of at least one structure (16), wherein the carrier (2) has a triangular cross section at least in sections with the at least one mounting portion (6) being arranged on an edge of the triangular cross section; and a heat sink body portion (8) arranged adjacent to the at least one mounting portion (6), wherein the heat sink body portion (8) protrudes sidewards from the at least one mounting portion (6); and wherein the at least one structure (16) is mounted to the at least one mounting portion (6), wherein the at least one structure (16) comprises at least one mounting face (6a) for receiving the at least one lighting module (4), wherein the at least one mounting face (6a) has an arrangement direction (18) and is configured for the at least one lighting module (4) to be arranged along the arrangement direction (18); the at least one lighting module (4) being mounted along the arrangement direction (18) on the at least one mounting face (6a); and the at least one light guide (4) being optically coupled to the at least one lighting module (4). The invention further relates to a method employed in the production of the lighting device (12), and an automotive exterior light comprising the lighting device (12).