Segmented Vehicle Headlight Light Guide Unit

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Solution Overview

Problem

Existing vehicle headlight lighting units face challenges with increased production effort due to thin walls between light guides, heat input issues from LEDs, and uneven reflector surface coating, particularly during injection molding.

Innovation Solution

The lighting unit is divided into two parts transverse to the emission direction, allowing for shorter light guide sections and optimized material selection for heat resistance and flow properties, with the light source-side part connected directly to LEDs and made of heat-resistant materials, and the emission-side part made of flowable thermoplastics, enabling uniform coating and reduced thermal stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If light guides are arranged directly next to one another to generate homogeneous light pattern, then light homogeneity is improved, but manufacturing complexity increases due to very thin walls between light guides

Engineering Contradiction:
Improvelight homogeneityVSAvoidmanufacturing effort
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The light guide unit is divided into a first light guide unit and a second light guide unit, which are arranged adjacent to one another. This segmentation allows each unit to have sufficient wall thickness for manufacturability while collectively providing the required light homogeneity across the entire headlight assembly.

Inventive Principle:
Principle #1Segmentation

2Illumination intensity

If light guides have small cross-section to concentrate light emission, then light concentration is improved, but coating uniformity deteriorates because aluminum vapor cannot be distributed evenly

Engineering Contradiction:
Improvelight concentrationVSAvoidcoating uniformity
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

Dividing the light guide unit into separate first and second units with larger individual cross-sections enables uniform aluminum vapor coating during manufacturing, while maintaining the required light concentration through the coordinated arrangement of multiple light guide units.

Inventive Principle:
Principle #1Segmentation

3Quantity of substance

If thin walls are used between light guides to reduce material, then material usage is reduced, but heat resistance deteriorates due to thermal damage risk

Engineering Contradiction:
Improvematerial usageVSAvoidheat resistance
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

The division into first and second light guide units allows each unit to have adequate wall thickness for heat resistance. The segmented structure manages thermal loads from LED arrays more effectively than a single thin-walled unit, preventing thermal damage while using reasonable material quantities.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If light guide unit is produced as single piece by injection molding, then production simplicity is maintained, but production reliability decreases due to increased risk of faulty castings

Engineering Contradiction:
Improveproduction process simplicityVSAvoidcasting reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

Producing the light guide unit as separate first and second units reduces the size and complexity of individual injection molding operations, lowering the risk of faulty castings. The segmented units are then assembled to form the complete light guide unit, maintaining production efficiency while improving reliability.

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 design enhances heat resistance, reduces manufacturing effort, and ensures even coating of reflector surfaces, resulting in improved light output and reliability while minimizing thermal damage and scattering at the separating surfaces.

Implementation Method 1

a plurality of artificial light sources, being bundled in the direction of emission by a corresponding plurality of light guides arranged next to one another

Methodology Applied
Scientific EffectLight transmission and bundling: Optical Fibre

Implementation Method 2

the reflector surfaces can no longer be reliably coated evenly, since the aluminum vapor used to apply the layer cannot be distributed over the entire depth of the light guides during vapor deposition

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2875283B2Lighting unit for a headlight
Publication Date: 2019.05.01 ZKW GRP GMBH
  • EP2875283B2 patent drawingFigure 1~2
  • EP2875283B2 patent drawingFigure 3~4
  • EP2875283B2 patent drawingFigure 5~7

AI summary

In a lighting unit (1) for a headlight, in particular a vehicle headlight, composed of multiple light sources (2) and a light-guiding unit (3) with multiple light-guiding means (6), in each case a light-guiding means (6) is assigned to one light source (2), and the light-guiding unit (3) is composed of at least two components (4, 5) which can be connected to one another, wherein a light-source-side component (4) of the light-guiding unit (3) is arranged between the light sources (2) and an irradiation-side component (5) of the light-guiding unit (3), in the irradiation direction of the light-guiding unit (3).