Dust-Tight Micromirror Light Module for Vehicle Headlights

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing light modules for motor vehicle headlights often suffer from locally dark spots and blurred images due to dust particles in the beam path between the micromirror array and secondary optics, leading to light losses and suboptimal light distribution.

Innovation Solution

A dust-tight interior is created within the light module by enclosing the light source, primary optics, and micromirror array, using a housing design with a front part, central support element, printed circuit boards, and a dust-tight pressure equalization membrane, ensuring that the light path from the source to the secondary optics remains sealed and free from dust, with components assembled in a clean room to prevent particle ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the light module interior is open to the environment, then assembly and maintenance are easier, but dust particles enter the beam path causing dark spots and blurred images

Engineering Contradiction:
Improveassembly easeVSAvoiddust contamination
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The light module interior is segmented from the external environment through a dust-tight seal, creating a controlled clean interior space while maintaining separate access paths for assembly and operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A dust-tight seal acts as an intermediary barrier between the clean interior beam path and the external environment, allowing pressure equalization while preventing dust ingress

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a dust-tight seal is implemented, then dust particles are kept out of the beam path, but pressure differences may damage the micromirror array

Engineering Contradiction:
Improvedust contaminationVSAvoidpressure difference
Core Design Contradiction:
Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The pressure equalization membrane serves as a mediator that allows pressure equalization between the sealed interior and external environment while maintaining the dust-tight seal integrity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

A flexible pressure equalization membrane is used to balance pressure differences across the dust-tight seal, preventing stress damage to the micromirror array while maintaining sealing

Inventive Principle:
Principle #30Flexible shells and thin films

3Object-affected harmful factors

If the entire light module is sealed dust-tight, then dust is prevented from entering, but manufacturing complexity and sealing requirements increase

Engineering Contradiction:
Improvedust contaminationVSAvoidsealing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The dust-tight sealing requirement is extracted and applied only to the critical beam path interior, while other non-critical areas of the light module can have simpler construction

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The dust-tight seal structure is designed to perform multiple functions: sealing the beam path, enabling pressure equalization, and facilitating assembly through standardized interfaces

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

This configuration eliminates dark spots and blurred images, ensuring a clear and efficient light distribution by keeping dust particles out of the beam path, thereby enhancing the module's performance and reducing light losses.

Implementation Method 1

a dust-tight pressure equalization membrane is provided, by means of which pressure equalization is possible

Methodology Applied
Scientific EffectPressure equalization: Pascal's Law

Implementation Method 2

the dust-tight interior is enclosed by a front part of the housing, a central support element, a DMD chip, a first printed circuit board, the secondary optics lens and a dust-tight pressure equalization membrane

Methodology Applied
Scientific EffectDust-tight sealing: Filter (physical)

Implementation Method 3

Each individual micromirror is only 8 x 8 micrometers in size, for example. A position of each individual micromirror can be switched between two positions. In one position it reflects the incident light onto the secondary optics, and in the other position it reflects the light onto an absorber

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 4

The light source, the primary optics, the array of micromirrors and the secondary optics are arranged relative to one another such that light emanating from the light source and directed by the primary optics onto the array of micromirrors can be reflected by the array of micromirrors onto the refractive secondary optics

Methodology Applied
Scientific EffectLight refraction: Refraction

Data Source

PatentEP3546822B1Micromirror-comprising light module for a motor vehicle headlight
Publication Date: 2022.05.04 MARELLI GERMANY GMBH
  • EP3546822B1 patent drawingFigure 1
  • EP3546822B1 patent drawingFigure 2~3
  • EP3546822B1 patent drawingFigure 4

AI summary

A light module (10) for a motor vehicle headlight is presented, comprising a light source (12), a primary optic (14), an arrangement of micromirrors (16.4) and a refractive secondary optic (18), wherein the light source (12), the primary optic (14), the arrangement of micromirrors (16.4) and the secondary optic (18) are arranged relative to each other such that light (22) emanating from the light source (12) and directed by the primary optic (14) onto the arrangement of micromirrors (16.4) is reflected by the arrangement of micromirrors (16.4) onto the refractive secondary optic (18). The light module (10) is characterized by having an interior (26) which is enclosed in a dustproof manner by a housing front part (28), a central support element (30), a DMD chip (16), a first circuit board (20), the secondary optics (18) and a dustproof pressure equalization membrane (32).