Variable Rib Optical Guide for Homogeneous Vehicle Lighting

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Solution Overview

Problem

Existing optical guides for motor vehicle lighting and signaling face challenges in maintaining light homogeneity, especially in complex and extended shapes, leading to defects in light distribution.

Innovation Solution

The optical guide features a variable rib shape with varying thickness and inclination along its length, which modulates light quantity and promotes even light distribution, combined with a unitary sheet and a mask with grained windows to ensure consistent light output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a complex and extended optical guide shape is used to create distinctive vehicle signatures, then the visual appeal and adaptability are improved, but light homogeneity deteriorates

Engineering Contradiction:
Improveshape complexityVSAvoidlight homogeneity
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The rib thickness is varied locally along the length of the optical guide, being thicker at certain positions and thinner at others. This local variation in rib thickness allows different sections of the guide to have different light transmission characteristics, compensating for light loss in extended areas while maintaining homogeneity in the overall light distribution across the complex shape.

Inventive Principle:
Principle #3Local quality

2Area of stationary object

If the optical guide length is increased to extend lighting coverage, then the lighting area is improved, but light quantity deteriorates

Engineering Contradiction:
Improvelighting areaVSAvoidlight quantity
Core Design Contradiction:
Area of stationary objectVSIllumination intensity

Solution Approach 1:

The rib thickness parameter is changed along the length of the optical guide. By making the rib thicker at positions where light quantity needs to be increased, the guide compensates for light loss over distance, maintaining adequate illumination intensity across the extended lighting area.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If the rib thickness is increased to improve light transmission, then light quantity is improved, but manufacturing complexity deteriorates

Engineering Contradiction:
Improvelight quantityVSAvoidrib shape complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The rib is segmented into different thickness zones along its length, with each section having a specific thickness value. This segmentation allows the rib to provide varying light transmission characteristics without requiring complex continuous variations, simplifying the manufacturing process while still achieving the desired light distribution.

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 configuration enables homogeneous light signaling across complex shapes, compensating for light reduction and avoiding parallax defects, while being cost-effective and suitable for plastic injection molding.

Implementation Method 1

Light from light sources enters the guide through one of the lateral faces. The light rays then propagate by successive reflections off the two principal faces of the guide. These faces form diopters with the surrounding air, allowing incident rays at an angle greater than the critical angle of refraction to undergo total internal reflection.

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The thickness of the rib along the principal direction of the guiding section is variable. The variable shape of the rib includes an inclination of the rib with respect to a direction transverse to the main direction... and/or the thickness e of the rib.

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3899362B1Light module with mask
Publication Date: 2024.05.15 VALEO VISION SA
  • EP3899362B1 patent drawingFigure 1~2
  • EP3899362B1 patent drawingFigure 3~4
  • EP3899362B1 patent drawingFigure 5~6

AI summary

The invention relates to an optical guide (16) made of transparent or translucent material, running in a main direction, and comprising a rounded, tubular guide portion (18.1, 18.2), forming, with the outside environment, a rounded, tubular dioptric interface, said portion being suitable for guiding light along the main direction through successive reflections off the dioptric interface; and a rib (22.1, 22.2) adjacent to the guide portion (18.1, 18.2), suitable for allowing light to exit said portion. The rib (22.1, 22.2) exhibits a variable shape along the main direction so as to modify the amount of light that exits along said direction. The invention also relates to a lighting module comprising the optical guide (16) and a lighting device comprising the lighting module.