Vehicle Laser Headlight Microstructure Deflects Unconverted Light
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Solution Overview
Problem
Laser light sources in motor vehicle headlights emit coherent, monochromatic light, posing safety risks due to high radiation intensities, and existing passive safety systems that absorb or scatter light to prevent blinding also reduce usable light, resulting in significant power loss when the radiation converter is functional.
Innovation Solution
A microstructure is integrated into the imaging optics of the lighting device, configured to deflect unconverted laser light in a controlled manner, ensuring that the deflected light contributes to the resulting light distribution, thereby reducing the hazard potential while minimizing light loss in fault-free conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a radiation converter is used to convert laser light into broadband white light, then the desired white mixed light is generated, but if the radiation converter is destroyed or removed, dangerous laser light can escape without conversion
Solution Approach 1:
A beam trap is introduced as an intermediary safety component positioned to intercept laser light in the event the radiation converter fails. The beam trap absorbs or safely redirects the dangerous laser light, preventing it from reaching road users while not interfering with normal operation when the radiation converter is functional.
Solution Approach 2:
The beam trap is pre-positioned and ready to activate before any actual harm occurs. In the event of radiation converter failure, the beam trap immediately provides a safety cushion by capturing the escaping laser light, preventing potential blinding of road users without requiring active detection or response systems.
2Object-affected harmful factors
If passive safety systems such as beam traps or scattering elements are used to absorb or scatter laser light in case of fault, then road users are protected from laser light, but less usable light is available to generate the resulting light distribution, causing power loss of 15-30%
Solution Approach 1:
The beam trap is designed with localized functionality - it only activates its light-absorbing or scattering properties when laser light directly impinges on it during a fault condition. When the radiation converter is functional, the beam trap remains optically passive and does not interfere with the light path, thus avoiding any power loss during normal operation.
Solution Approach 2:
The beam trap's optical properties are dynamic rather than static. It transitions from being optically passive during normal operation to actively absorbing or scattering light only when needed during a fault condition, allowing the system to adapt its safety function based on operational state without continuous power loss.
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 the risk of blinding from unconverted laser light in case of a fault, with minimal impairment to the light distribution and no power loss when the system is functioning correctly, enhancing operational reliability and safety.
Implementation Method 1
the radiation converter is designed to convert and fan out laser light emitted by the laser light source into broadband, in particular white, secondary light compared to the laser light
Implementation Method 2
a radiation converter which contains a luminescence layer, in particular with phosphor
Implementation Method 3
If no activation process takes place between the absorption of energy and the emission, then one speaks of fluorescence
Implementation Method 4
The imaging optics are designed to deflect the secondary light in an emission direction of the illumination device
Implementation Method 5
a microstructure of a defined configuration is arranged in a locally limited impact area of the imaging optics, which is exposed to the laser light when the radiation converter is absent
Data Source
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AI summary
The invention relates to a lighting device (101) for a motor vehicle. This device comprises a laser light source (4) for emitting laser light (7), a radiation converter (6) containing a luminescent layer, in particular with phosphor, and an imaging optic (1). The radiation converter (6) is configured to convert and disperse the laser light (7) emitted by the laser light source (4) into secondary light (8) that is more broadband than the laser light (7), in particular white. The imaging optic (1) is configured to deflect the secondary light (8) into a beam direction (10) of the lighting device (101) to generate a resulting light distribution (11).In order to reduce the potential hazard from unconverted laser light (7) with as little power loss as possible in the fault-free case by means of a passive safety system, it is proposed that a microstructure (12) of defined design be arranged in a locally limited impact area (2) of the imaging optics (1), which is exposed to the laser light (7) when the radiation converter (6) is omitted, wherein the design of the microstructure (12) is such that deflection angles of light (8, 7) striking the impact area (2) are selected such that the light (13, 15) deflected by the microstructure (12) contributes to the generation of the resulting light distribution (11).