Vehicle Laser Lighting MEMS Thermal Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional scanning lighting devices with MEMS components using laser light sources face high thermal stress, leading to reduced service life and potential damage due to overheating.

Innovation Solution

A lighting device incorporating a vector scanner with MEMS components and a temperature sensor system that controls the laser light source's power to maintain the MEMS component within a safe temperature range, preventing overheating, and optionally using a Peltier element for active cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a laser light source is used in a scanning lighting device with MEMS components, then the lighting device can generate precise light distributions, but the MEMS component is subject to high thermal stress which reduces service life and may cause damage

Engineering Contradiction:
Improvelight distribution precisionVSAvoidMEMS component service life
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

A temperature sensor is introduced as an intermediary element between the laser light source and the MEMS component. The sensor detects temperature changes and provides feedback to the control unit, which then adjusts the laser power to maintain optimal operating conditions, preventing thermal damage to the MEMS component while preserving lighting precision

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements a feedback mechanism where the temperature sensor continuously monitors the MEMS component temperature and the control unit adjusts the laser light source power accordingly. This closed-loop control ensures the temperature remains within safe operating limits, preventing thermal stress accumulation and extending component service life

Inventive Principle:
Principle #23Feedback

2Illumination intensity

If the laser light source power is increased to improve lighting performance, then the light intensity is enhanced, but the thermal stress on the MEMS component increases

Engineering Contradiction:
Improvelight intensityVSAvoidMEMS component temperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The system dynamically adjusts the laser light source power based on real-time temperature feedback. The control unit modulates the power output to match the actual thermal conditions of the MEMS component, allowing optimal lighting performance when temperature is low and reducing power when thermal stress increases, thus balancing illumination intensity with thermal management

Inventive Principle:
Principle #15Dynamics

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 effectively reduces thermal stress on MEMS components, enhancing the service life and reliability of the lighting device by maintaining the temperature within a safe threshold, thereby preventing damage and ensuring consistent operation.

Implementation Method 1

a temperature sensor for detecting the temperature of the respective MEMS component is provided on a respective MEMS component

Methodology Applied
Scientific EffectTemperature sensing: Thermistor

Implementation Method 2

a laser light source made up of a number of laser diodes

Methodology Applied
Scientific EffectLaser emission: Laser

Implementation Method 3

a vector scanner onto which one or more light beams resulting from the light from the laser light source fall

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 4

the electrical power of an electrically operated cooling element (e.g. Peltier element) arranged on the MEMS component

Methodology Applied
Scientific EffectPeltier effect: Peltier Effect

Data Source

PatentEP3593038B1Lighting device for a motor vehicle
Publication Date: 2023.08.23 BAYERISCHE MOTOREN WERKE AG
  • EP3593038B1 patent drawingFigure 1

AI summary

The invention relates to a lighting device for a motor vehicle, comprising a laser light source (2) consisting of a number of laser diodes and a vector scanner (3) on which falls at least one light bundle (L) from the light of the laser light source (2). During the operation of the lighting device (1), the vector scanner (3) changes the position of the at least one light bundle (L) and thereby moves a light spot (SP) produced from the at least one light bundle (L), at a distance from the lighting device (1), in order to generate a pre-determined light distribution. The scan speed at which the light spot (SP) is moved and/or the scan path along which the light spot (SP) is moved can be varied by the vector scanner (3). The vector scanner (3) comprises at least one MEMS component, respectively containing a semiconductor chip (5) that is surrounded by a housing (6) and comprises an individual mirror (7) on which at least one light bundle (L) of the at least one light bundle (L) falls. The MEMS component is designed such that the mirror (7) is continuously tilted in order to move the light spot (SP). A temperature sensor (8) is provided on a respective MEMS component, for detecting the temperature (T) of the respective MEMS component (4). Furthermore, the lighting device (1) comprises a control device (9) designed such that it controls the electrical power of the laser light source (2) and/or a cooling element arranged on the MEMS component according to the detected temperature (T) of the respective MEMS component, in such a way that the detected temperature (T) does not exceed a pre-determined temperature threshold value (TS).