Vehicle Headlamp Exit Lens Groove Structure for Wide Light Distribution

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Solution Overview

Problem

Current motor vehicle headlight designs with smooth exit lenses fail to achieve the necessary width for a wide horizontal light distribution, particularly for low beam distributions, due to limitations in light image generation.

Innovation Solution

The outer surface of the exit lens is structured with a groove-shaped design, where grooves run vertically and are separated by vertical elevations, and the base surface is curved, allowing for increased normal distance along the exit lens surface to enhance light distribution width without bending the light-dark boundary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the outer surface of the exit lens is designed to be smooth, then the manufacturing precision is improved, but the light distribution width in the horizontal direction is insufficient

Engineering Contradiction:
Improvesmooth surface precisionVSAvoidlight distribution width
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The smooth base surface is segmented into multiple grooves running in the vertical direction, separated by elevations. This segmentation creates multiple light paths that spread horizontally, increasing the light distribution width while maintaining manufacturing precision through standardized groove patterns

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Vertical grooves are introduced on the exit lens surface to affect horizontal light distribution. By adding structural features in the vertical dimension (grooves and elevations), the patent achieves horizontal spreading of light, effectively using one dimension to control another

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

2Length of stationary object

If the overall height of the lighting unit is reduced to create a slit-shaped light exit surface, then the compactness is improved, but the horizontal light distribution width is limited

Engineering Contradiction:
Improveoverall heightVSAvoidlight distribution width
Core Design Contradiction:
Length of stationary objectVSArea of stationary object

Solution Approach 1:

The patent uses vertical grooves (vertical dimension) to achieve horizontal light spreading (horizontal dimension). This dimensional transformation allows the compact low-height design to still produce wide horizontal light distribution by directing light through grooved structures that spread beams horizontally

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

Solution Approach 2:

The exit lens surface is divided into multiple grooves and elevations that segment the light paths. This segmentation enables the compact lighting unit to generate multiple horizontal light beams that collectively achieve wide light distribution despite the limited overall height

Inventive Principle:
Principle #1Segmentation

3Area of stationary object

If the base surface is curved with increased normal distance, then the light distribution width is enhanced, but the structural complexity increases

Engineering Contradiction:
Improvelight distribution widthVSAvoidsurface curvature complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The base surface is curved with varying normal distances at different locations to optimize light distribution locally. The curvature is specifically designed in the horizontal direction while maintaining vertical groove structures, creating localized optical effects that enhance horizontal spreading without requiring complete redesign of the entire surface geometry

Inventive Principle:
Principle #3Local quality

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 achieves the desired horizontal blurring of light beams, resulting in a broader light distribution width while maintaining a straight light-dark boundary, even when the focal line is straight.

Implementation Method 1

on the reflector boundary surface of the reflector, the light rays propagating in the light-transmissive body are totally reflected

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a collimator for each light source, the collimator aligning the light beams fed into the collimator by the light source assigned to it into a light beam of light beams

Methodology Applied
Scientific EffectCollimation: Lens

Implementation Method 3

the light beams reflected by the reflector are deflected by the exit lens at least in the vertical direction

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 4

the outer surface of the exit lens is formed by a groove-shaped structure in a smooth base surface

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 5

This configuration achieves the desired horizontal blurring of light beams

Methodology Applied
Scientific EffectScattering: Scattering

Data Source

PatentEP3403021B1Light module for a vehicle headlamp with a dark-light-boundary
Publication Date: 2021.10.27 ZKW GRP GMBH
  • EP3403021B1 patent drawingFigure 1
  • EP3403021B1 patent drawingFigure 2~3
  • EP3403021B1 patent drawingFigure 4~5a

AI summary

The invention relates to a lighting unit for a motor vehicle headlight for generating a light bundle with a cutoff line, comprising the following: - at least one light source (1, 1a, 1b), - a reflector (2), - an outlet lens (3) with an outer surface (3a), - a focal line region (4) which is arranged between the reflector (2) and the outlet lens (3), - and a collimator (10, 10a, 10b) for each light source (1, 1a, 1b). The collimator (10, 10a, 10b) aligns light beams (S1) supplied by the paired light source (1, 1a, 1b) to the collimator (10, 10a, 10b) into a light bundle of light beams (S2), and the reflector deflects the light beams of the light bundle exiting the collimator into a focal line lying in the focal line region. The light beams reflected by the reflector are deflected from the outlet lens at least in the vertical direction such that the light beams exiting the outlet lens form a light distribution with a cutoff line. The outer surface (3a) of the outlet lens (3) is made of a groove-shaped structure in a smooth base surface (BF). The grooves (3b) which forms the groove-shaped structure run substantially in the vertical direction, and two grooves (3b) lying adjacently to each other in the horizontal direction are preferably separated by an elevation which runs substantially in the vertical direction in particular and which extends preferably over the entire vertical extension of the grooves (3b).