Vehicle Headlight Light Guide With Diffuser Elevation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

State-of-the-art light guides for vehicle headlamps suffer from inhomogeneous light distribution near the coupling region, leading to reduced effective light exit surface and increased material and assembly costs due to the need for screens to prevent unwanted emissions, which also reduces the installation space and optical length.

Innovation Solution

Incorporating a diffuser area with a gradual elevation along the light guide, starting from the light coupling surface and extending into the emission area, ensures homogeneous light distribution by smoothing the transition and optimizing light coupling, and using multiple parallel elevations further enhances this homogeneity. Additionally, arranging light guides adjacently with shared coupling surfaces allows for a common light source and reduced installation space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If screens are provided to cover the coupling-in area to prevent unwanted emissions, then the external appearance of the headlight is improved, but the effective length of the light guide is reduced and installation space is consumed

Engineering Contradiction:
Improveunwanted emissionsVSAvoideffective length of light guide
Core Design Contradiction:
Object-generated harmful factorsVSLength of stationary object

Solution Approach 1:

The invention extracts and removes the screens from the light guide design. Instead of using screens to prevent unwanted emissions, the patent relies on the optimized light coupling geometry and the specific arrangement of light scattering elements to achieve the desired light distribution without requiring additional blocking components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The light guide is segmented into distinct functional areas: a coupling-in area with specific scattering elements, a coupling-out area with different scattering elements, and an intermediate section. This segmentation allows each area to perform its specific function optimally, preventing unwanted emissions through controlled light scattering rather than physical blocking.

Inventive Principle:
Principle #1Segmentation

2Object-generated harmful factors

If screens are provided to cover the coupling-in area, then unwanted emissions are prevented, but the light guide emits less light with the same power of the light source

Engineering Contradiction:
Improveunwanted emissionsVSAvoidlight emission
Core Design Contradiction:
Object-generated harmful factorsVSIllumination intensity

Solution Approach 1:

The screens are completely removed from the design. The invention achieves unwanted emission prevention through the inherent optical properties of the light guide structure and the strategic placement of light scattering elements, which redirect light constructively rather than blocking it.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the optical parameters of the light guide by incorporating light scattering elements with specific scattering characteristics. These elements modify the light propagation path and distribution, achieving homogeneous light emission while preventing unwanted emissions through controlled scattering rather than absorption or blocking.

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If screens are provided to cover the coupling-in area, then unwanted emissions are prevented, but material and assembly costs increase

Engineering Contradiction:
Improveunwanted emissionsVSAvoidmaterial and assembly costs
Core Design Contradiction:
Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the screens from the light guide assembly. By using the light guide structure itself with integrated light scattering elements to control light distribution, the design removes the need for separate screen components, thereby reducing material costs and simplifying assembly procedures.

Inventive Principle:
Principle #2Taking out (Extraction)

4Object-generated harmful factors

If screens are provided to cover the coupling-in area, then unwanted emissions are prevented, but installation space requirements increase

Engineering Contradiction:
Improveunwanted emissionsVSAvoidinstallation space
Core Design Contradiction:
Object-generated harmful factorsVSVolume of stationary object

Solution Approach 1:

The screens are completely removed from the light guide design. The invention achieves emission control through the optimized geometry and light scattering elements integrated into the light guide itself, eliminating the need for additional space-consuming blocking components.

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

The diffuser area achieves a homogeneous light distribution along the length of the light guide, increasing the effective light exit surface and reducing material and assembly costs, while the adjacent light guides configuration simplifies assembly and reduces space requirements, enhancing the overall efficiency and compactness of the headlight design.

Implementation Method 1

the emission area comprises a plurality of light scattering elements along the light guide, by means of which light can be reflected substantially transversely to the main light path

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

a light coupling surface at one end for coupling light into the light guide

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

light can be reflected substantially transversely to the main light path

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP3208525B1Light guide for a vehicle headlight
Publication Date: 2018.05.02 ZKW GRP GMBH
  • EP3208525B1 patent drawingFigure 1~2
  • EP3208525B1 patent drawingFigure 3~6
  • EP3208525B1 patent drawingFigure 7~8

AI summary

Light guide (100) for a vehicle headlight, wherein the light guide (100) has an elongated shape along a main light path and has a light coupling surface (110) at one end for coupling light into the light guide (100), and the light guide (100) comprises a beaming area (120) with a beaming area start (121) and a beaming area end, wherein the beaming area (120) along the light guide (100) comprises several light-scattering elements (130) through which light can be reflected substantially transversely to the main light path in order to be emitted from the light guide (100), wherein the light guide (100) comprises a diffuser area (140) with a diffuser area start (141) and a diffuser area end (142), which is formed on the surface of the light guide (100) as at least one substantially longitudinally The elevation (150) running along the light guide (100) is formed,wherein the diffuser area start (140) is arranged downstream of the light coupling surface (110) from the main light path and the diffuser area end (142) is arranged downstream of the diffuser area start (141), and the emission area start is arranged downstream of the diffuser area start (141) and the emission area end is arranged downstream of the emission area start.