Spherical Dome Corrective Part for Vehicle Headlamp Optical Efficiency

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Solution Overview

Problem

Current motor vehicle headlamp systems with Adaptive Driving Beam (ADB) functions face issues with light ray refraction at the interface between light guides and the surrounding medium, leading to reduced optical efficiency and unsatisfactory imaging quality.

Innovation Solution

A primary optical element for motor vehicle headlamps featuring light guides connected to a corrective part with a substantially spherical dome-shaped output face, ensuring minimal refraction and maintaining the reduced opening of the light beam, while the light guides and corrective part are made from the same material with identical refractive indices, enhancing optical efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If light guides are used in the headlamp system, then the lighting structure is simplified and ADB function is enabled, but light ray refraction at the interface causes strong deviation from the optical axis and reduced optical efficiency

Engineering Contradiction:
Improvelighting structureVSAvoidoptical efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

A corrective part with a spherical interface is introduced as an intermediary element between the light guide and the external environment. This corrective part has a refractive index intermediate between the light guide material and air, reducing the refraction angle at the interface and minimizing ray deviation from the optical axis.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The refractive index parameter is changed by introducing a corrective part with a specific refractive index value (1.33) that is intermediate between the light guide (n=1.46) and air (n=1.00). This parameter change reduces the refraction effect at the interface according to Snell's law, thereby improving optical efficiency.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If light guides are used in the headlamp system, then the lighting structure is simplified and ADB function is enabled, but ray deviation causes poor imaging quality

Engineering Contradiction:
Improvelighting structureVSAvoidimaging quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The corrective part serves as an intermediary optical element that compensates for the ray deviation caused by the light guide interface. By positioning this corrective part at the light guide output, it refines the ray paths and improves the quality of the projected image on the road.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If a spherical dome-shaped corrective part is added to the light guide output, then refraction is minimized and optical efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improveoptical efficiencyVSAvoidoptical element structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The corrective part is merged with the light guide to form a single integrated optical element. This combining of the light guide and corrective part into one piece structure reduces assembly complexity and manufacturing steps while maintaining the optical benefits of the corrective interface.

Inventive Principle:
Principle #5Merging (Combining)

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 improves optical efficiency by minimizing light ray deflection and maintaining the reduced opening of the light beam, resulting in better imaging quality and reduced light loss, thereby enhancing the overall performance of the headlamp system.

Implementation Method 1

the respective refractive indices of the light guides and of the corrective part are substantially identical... At the exit from the guides, the rays undergo little or no refraction

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2743567B1Primary optical element, lighting module and headlight for motor vehicle
Publication Date: 2022.05.11 VALEO VISION SA
  • EP2743567B1 patent drawingFigure 1~2
  • EP2743567B1 patent drawingFigure 3~4
  • EP2743567B1 patent drawingFigure 5~8

AI summary

The element has a set of light guiding units (3a-3d) connected at an output to a corrective part (4), where the corrective part includes half-sphere shape. The corrective part comprises an exit surface (41) having a shape of spherical dome. The light guiding units and the corrective part form an integral structure, and are manufactured from same material such as polymer. The exit surface is centered approximately on an outlet side of one of the light guiding units. A front face of each light guiding unit is provided with a convex portion. Independent claims are also included for the following: (1) an optical assembly (2) a lighting module.