Vehicle Light Source Dimming via Pixel Modulation

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Solution Overview

Problem

Vehicle lighting systems face challenges in achieving desired light distributions while minimizing electrical power consumption to avoid temperature issues and reduce energy consumption.

Innovation Solution

A lighting device with a light source, control device, and surface modulation device that allows pixel-by-pixel modulation of light, using pulse width modulation (PWM) to adjust current intensity and duty cycle, determining the raw light distribution with the lowest illuminance profile that meets the specified light distribution requirements, thereby reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a light source is used to achieve desired light distribution, then illumination intensity is improved, but electrical power consumption increases

Engineering Contradiction:
Improvelight distributionVSAvoidelectrical power consumption
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent segments the light distribution control into two independent parts: the light source provides overall illumination at reduced power, while the micromirror module segments and directs specific light paths to achieve the desired light distribution pattern. This allows the light source to operate at lower intensity while still meeting illumination requirements through optical steering.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The micromirror module acts as an intermediary between the light source and the target area. It receives light from a low-power light source and redirects it to create the desired light distribution, thereby decoupling the power consumption from the illumination intensity at the target.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If light source power is increased to achieve desired light distribution, then illumination intensity is improved, but temperature increases

Engineering Contradiction:
Improvelight distributionVSAvoidtemperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

By segmenting the optical system into a low-power light source and a micromirror-based steering mechanism, the patent reduces the thermal load at the light source while maintaining the required light distribution through precise optical control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The micromirror module serves as a thermal intermediary, allowing the light source to operate at low temperature while still delivering adequate illumination to the target area through efficient light redirection rather than increased power.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Illumination intensity

If micromirrors are operated at high duty cycle to improve light distribution, then illumination intensity is improved, but temperature and storage problems increase

Engineering Contradiction:
Improvelight distributionVSAvoidtemperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The micromirrors operate using periodic switching between different angular positions rather than continuous operation at high duty cycle. This periodic action allows the mirrors to cool down between activation cycles, reducing thermal accumulation and associated storage problems while maintaining effective light distribution control.

Inventive Principle:
Principle #19Periodic action

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 enables the generation of desired light distributions with minimal electrical power usage, reducing temperature and energy consumption, and allowing for dynamic adjustment based on environmental parameters.

Implementation Method 1

The light source generates light with the corresponding intensity in accordance with this electric current

Methodology Applied
Scientific EffectLight emission from light source: Light Emitting Diode

Implementation Method 2

a surface modulation device with which the light from the light source can be modulated pixel by pixel

Methodology Applied
Scientific EffectLight modulation:

Implementation Method 3

Pulse width modulation (PWM) is particularly suitable for this. The duty cycle or duty cycle, which can be between 0% and 100%, determines the relationship between the on-time and off-time

Methodology Applied
Scientific EffectPulse width modulation:

Data Source

PatentEP3214900B1Dimming of a light source
Publication Date: 2018.12.12 AUDI AG
  • EP3214900B1 patent drawingFigure 1~3
  • EP3214900B1 patent drawingFigure 4~5
  • EP3214900B1 patent drawing

AI summary

The aim is to generate a desired light distribution in an energy-efficient manner. For this purpose, a lighting device (5) for a vehicle is provided, comprising a light source (7), a control unit (6) for controlling the light source (7), and an area modulation device (9) with which the light from the light source (7) can be modulated pixel by pixel. The control unit allows the light source (7) to be controlled in such a way that several raw light distributions (13 to 16) can be generated. The lighting device (5) includes a computing unit with which the one of the several raw light distributions (13 to 16) can be determined that results in the lowest possible power consumption of the light source while simultaneously ensuring that a predetermined light distribution (17) can still be achieved with the area modulation device (9).