Vehicle Light Guide End Section for Homogeneous Illumination

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Solution Overview

Problem

Existing lighting devices for motor vehicles suffer from uneven light intensity at the end sections of elongated light guides, necessitating additional mounting space for shading to achieve homogeneous illumination.

Innovation Solution

A lighting device with a light guide comprising a main section, an end section, and a free end, featuring a cavity for the light source, microscopic surface roughening for uncontrolled scattering, and macroscopic scattering optical elements for controlled scattering, ensuring uniform light emission without the need for shading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the light guide is equipped with optical elements for coupling out, refracting, scattering, and reflecting the light, then the light guidance and emission along the main section is uniform, but the end section light intensity remains uneven and requires additional shading components

Engineering Contradiction:
Improvelight homogeneityVSAvoidadditional shading components
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The light guide is divided into two distinct sections: a main section with extraction elements for uniform light guidance, and an end section with scattering elements for light homogenization. This segmentation allows each section to be optimized for its specific function, eliminating the need for additional shading components while achieving overall light uniformity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different optical properties are applied to different sections of the light guide. The main section has extraction elements for controlled light coupling out, while the end section has scattering elements for uncontrolled light scattering. This local differentiation of optical quality enables the end section to homogenize light without requiring external shading components.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If the end section of the light guide is shaded to achieve homogeneous illumination, then the light intensity uniformity is improved, but the mounting space requirement increases

Engineering Contradiction:
Improvelight homogeneityVSAvoidmounting space
Core Design Contradiction:
Illumination intensityVSArea of stationary object

Solution Approach 1:

The light homogenization function is merged directly into the end section of the light guide by integrating scattering elements into its structure. This combines the light guidance function and the homogenization function into a single integrated component, eliminating the need for separate shading components and reducing mounting space requirements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The end section of the light guide serves its own homogenization needs by incorporating scattering elements directly into its structure. Instead of requiring external shading components to achieve uniform light distribution, the light guide structure itself provides the homogenization function through its scattering elements.

Inventive Principle:
Principle #25Self-service

3Illumination intensity

If fiber optic cable is used to emit light evenly over the entire length including end sections, then the light homogeneity is improved, but the cost increases

Engineering Contradiction:
Improvelight homogeneityVSAvoidcost
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The optical parameters of the light guide are changed by introducing scattering elements in the end section. This modifies the light propagation characteristics to achieve even light distribution without requiring expensive fiber optic cables. The parameter change involves transitioning from purely guided light transmission to a combination of guided transmission and scattering-based homogenization.

Inventive Principle:
Principle #35Parameter changes

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

Achieves homogeneous illumination along the entire length of the light guide, saving installation space by integrating light homogenization directly within the end section, utilizing a combination of surface roughening and macroscopic scattering elements.

Implementation Method 1

Light guides are used to guide and emit light from a light source in the desired direction and at the desired intensity

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The main section contains a surface for light extraction parallel to the longitudinal axis of the light guide and is equipped with extraction elements for reflecting the light out of the light guide

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

The end section of the light guide comprises microscopic surface roughening for uncontrolled light scattering

Methodology Applied
Scientific EffectScattering: Scattering

Implementation Method 4

The end section of the light guide comprises macroscopic scattering optical elements for controlled light scattering

Methodology Applied
Scientific EffectScattering: Scattering

Data Source

PatentEP4632270A1Lighting device for motor vehicles
Publication Date: 2025.10.15 SKODA AUTO AS
  • EP4632270A1 patent drawingFigure 1
  • EP4632270A1 patent drawingFigure 2
  • EP4632270A1 patent drawingFigure 3

AI summary

A lighting device for motor vehicles, comprising a light source (1) and a light guide made of transparent material. The light guide is designed to increase the homogeneity of the illumination in the end section (7) of the light guide (the first few centimeters). The light guide comprises a main section (6), an end section (7), and at least one free end (2). The end section (7) comprises a cavity (4) and a surface (5) for light entry, wherein the longitudinal axis (3) of the light guide extends through the cavity (4) and the cavity (4) is open at the free end (2) of the light guide. The light source (1) extends into the cavity (4) and is directed onto the surface (5) for light entry in the direction of the longitudinal axis (3) of the light guide. The main section (6) comprises a surface (8) for light output, which is provided with output elements (40) for reflecting the light from the light guide.The end section (7) of the light guide comprises a microscopic roughening (20) of the surface for uncontrolled light scattering and macroscopic scattering optical elements (30) for controlled light scattering.