Vehicle Light Guide Conical End Region Lateral Emission Control

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Solution Overview

Problem

Existing light guides for vehicle lighting devices suffer from unwanted light reflections and emissions from the end region, leading to disturbing light beams and impaired appearance due to hot spots.

Innovation Solution

The light guide features a conical or frustoconical end region with a base facing the light guide, which effectively redirects and absorbs or scatters light to minimize lateral emissions, thereby reducing disturbing light rays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a flat surface is used at the end region of the light guide, then the light guide structure is simple, but unwanted light reflections occur and light beams emerge laterally in disturbing directions

Engineering Contradiction:
Improvelight guide structureVSAvoidunwanted light reflections
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The end region of the light guide is designed with a curved surface instead of a flat surface. This curvature causes incident light rays to be reflected in different directions, preventing the formation of concentrated lateral light beams and reducing disturbing reflections while maintaining structural simplicity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of manufacture

If a flat surface is used at the end region of the light guide, then manufacturing is easy, but hot spots are created and appearance is impaired

Engineering Contradiction:
Improveend region fabricationVSAvoidhot spots
Core Design Contradiction:
Ease of manufactureVSIllumination intensity

Solution Approach 1:

The curved surface at the end region disperses light reflections, preventing concentration of light intensity in specific areas. This eliminates hot spots and creates a more uniform appearance while remaining compatible with standard manufacturing processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Object-generated harmful factors

If the end region has a curved surface, then unwanted light emissions are reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvelateral light emissionsVSAvoidcurved surface fabrication
Core Design Contradiction:
Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The curved surface can be implemented using conventional manufacturing techniques such as injection molding or CNC machining, making the increased complexity manageable. The curvature effectively reduces lateral light emissions by scattering reflections while remaining producible with standard equipment.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 significantly reduces unwanted light emissions from the end region, enhancing the appearance of the lighting device by minimizing hot spots and ensuring a more uniform light distribution.

Implementation Method 1

The light guide features a conical or frustoconical end region with a base facing the light guide, which effectively redirects and absorbs or scatters light to minimize lateral emissions

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

The light guide features a conical or frustoconical end region with a base facing the light guide, which effectively redirects and absorbs or scatters light to minimize lateral emissions

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

The light guide features a conical or frustoconical end region with a base facing the light guide, which effectively redirects and absorbs or scatters light to minimize lateral emissions

Methodology Applied
Scientific EffectAbsorption: Absorption (EM radiation)

Data Source

PatentEP4133208B1Light guide for a lighting device of a vehicle and lighting device with such a light guide
Publication Date: 2025.05.28 HELLA GMBH & CO KGAA
  • EP4133208B1 patent drawingFigure 1~2
  • EP4133208B1 patent drawingFigure 3~4
  • EP4133208B1 patent drawingFigure 5

AI summary

Light guide (10) for a lighting device of a vehicle, comprising an entrance surface into which light (11) can enter, at least one lateral exit surface (12) from which a portion of the light (11) that has entered can exit, an end region (13) through which a portion of the light (11) that has entered can exit, wherein the end region (13) is structured and/or shaped in such a way that the portion of light (11) which laterally emerges from the region adjacent to the end region (13) after reflection at or in the end region (13) is reduced or minimised.