Vehicle Illumination Assembly With Single-Source Branched Lightguide

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Solution Overview

Problem

Existing automotive lighting systems require multiple light sources or complex branching geometries to achieve a three-dimensional illumination effect, which increases cost and size, limiting design flexibility.

Innovation Solution

A branched lightguide with a single row of LEDs and a branched lightguide structure featuring a common intersection with a reflection surface that directs light to multiple branches, allowing for a three-dimensional illumination effect using a single light source, even with small angles between branches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple rows of LEDs are used to provide light for the branched lightguide, then sufficient light can be distributed to all branches, but the device complexity and cost increase

Engineering Contradiction:
Improvelight distribution to branchesVSAvoidnumber of LED rows
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The single row of LEDs is segmented into multiple virtual light sources through the reflection surface, which divides the incident light into different directions to illuminate multiple branches. This segmentation allows one physical light source to serve multiple functions that would traditionally require multiple light sources.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A reflection surface is introduced as an intermediary element between the single row of LEDs and the multiple branches. This reflection surface redirects light from the first branch to the second branch, enabling light distribution without requiring additional LED rows. The reflection surface acts as a mediator that solves the light distribution problem while maintaining device simplicity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If branches are arranged with small angles between them, then space requirements are reduced, but light distribution to all branches becomes difficult

Engineering Contradiction:
Improvespace requirementsVSAvoidlight distribution to branches
Core Design Contradiction:
Volume of moving objectVSIllumination intensity

Solution Approach 1:

The solution transitions from a two-dimensional light distribution problem to a three-dimensional solution by utilizing the reflection surface that operates in a different spatial dimension. The reflection surface is inclined at a specific angle to redirect light in a direction that accounts for the small angle between branches, enabling effective light distribution in compact three-dimensional space.

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

Solution Approach 2:

The inclination angle of the reflection surface is optimized as a key parameter to achieve effective light redistribution. By adjusting this parameter, the system adapts to small branch angles while maintaining sufficient light intensity. The reflection surface's angular parameter is specifically designed to compensate for the reduced spatial separation between branches.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a single row of LEDs is used with a branched lightguide, then device complexity and cost are reduced, but providing sufficient light to all branches regardless of angles is challenging

Engineering Contradiction:
Improvenumber of LED rowsVSAvoidlight distribution adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The reflection surface is designed to perform multiple functions: it reflects light to the second branch, allows light to pass through to the third branch, and can be adjusted to accommodate different branch angles. This multi-functional element enables a single row of LEDs to serve multiple branches with varying geometries, providing the adaptability that would traditionally require multiple light sources.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 a distinctive three-dimensional illumination pattern with reduced space requirements and cost, allowing for a more flexible and aesthetically pleasing design.

Implementation Method 1

The first branch comprises a reflection surface extending in the intersection. The reflection surface is adapted for reflecting a first part of light from the first branch to the second branch.

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4375568B1Illumination assembly for a vehicle
Publication Date: 2025.09.10 HELLA AUTOTECHNIK NOVA SRO
  • EP4375568B1 patent drawingFigure 1
  • EP4375568B1 patent drawingFigure 2
  • EP4375568B1 patent drawingFigure 3~4

AI summary

Illumination assembly for a vehicle, the assembly comprising a light source and a branched lightguide (1), wherein the branched lightguide (1) has at least three plate-shaped branches with a common intersection (8) extending along their width (2). The first branch (5) comprises a light-entry surface (9) directed towards the light source and at least two of the at least three branches comprise light outcoupling elements (10) configured to direct light out of the branched lightguide (1) in a common direction (11). The first branch (5) comprises a reflection surface (12) extending in the intersection (8) and adapted for reflecting a first part of light from the first branch (5) to the second branch (6), wherein the reflection surface (12) extends through at most 80 % of thickness (4) of the first branch (5). The intersection (8) with the reflection surface (12) are adapted to guide a second part of the light from the first branch (5) to the third branch (7). When viewed from the common direction (11), outcoupling elements (10) on one branch of the branched lightguide (1) are preferably visible through another branch having outcoupling elements (10).