Vehicle Laser Headlight Reflector Coating for Converter Failure
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Solution Overview
Problem
Laser-based headlights for motor vehicles face issues with focused and high-intensity laser light emission when the radiation converter, which converts laser light into broadband secondary light, is damaged or missing, leading to potential disruptive effects.
Innovation Solution
The reflector in the lighting device is designed with a temperature-sensitive coating that remains reflective until a limit temperature is exceeded, at which point it becomes permeable or acts as a beam trap, reducing the intensity of laser light emission and preventing disruptive effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a laser light source is used to generate light for motor vehicle headlights, then light generation efficiency is significantly improved, but the risk of high-intensity focused laser light emission increases if the radiation converter is damaged or missing
Solution Approach 1:
The patent applies preliminary anti-action by providing protective means (beam trap or absorptive coating) in advance within the reflector structure. These protective elements are positioned to intercept laser light before it can be focused and emitted in harmful directions, preventing the harmful effect before it occurs. The beam trap or coating is pre-configured to become active when the radiation converter is damaged, blocking the focused laser light path.
Solution Approach 2:
The patent uses an intermediary element (beam trap or absorptive coating) that mediates between the laser light source and the external environment. This intermediary intercepts the focused laser light that would otherwise escape through the reflector, converting or blocking it before it can cause harmful effects. The beam trap acts as a mediator that absorbs or redirects the dangerous focused light while allowing normal operation when the radiation converter is intact.
2Adaptability or versatility
If the radiation converter is removed or damaged, then the conversion of laser light into broadband secondary light is lost, but laser light can escape without the fanning effect
Solution Approach 1:
The patent converts the harmful focused laser light into a beneficial signal by using a beam trap or absorptive coating that detects and absorbs the escaped laser light. The harmful focused light that would otherwise cause safety issues is instead captured and converted into heat or absorbed energy, while simultaneously serving as an indicator that the radiation converter may be damaged. This allows the system to detect faults and prevent harmful emissions.
Solution Approach 2:
The patent extracts the protective function from the overall headlight system by implementing a separate beam trap or absorptive coating mechanism within the reflector structure. This extracted protective element specifically addresses the hazard of focused laser light escape without interfering with the normal light conversion function when the radiation converter is properly installed. The protective means can be independently activated or deactivated based on the operational state.
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 solution effectively reduces the intensity of laser light emission to zero in case of radiation converter failure, preventing disruptive effects and ensuring safe operation by distributing or absorbing the light, thus avoiding unwanted optical effects.
Implementation Method 1
radiation converters with phosphor are known, for example in the form of a phosphor coating, since phosphor has fluorescent properties and can thus create broadband secondary light, in particular white secondary light, from laser light of a suitable wavelength
Implementation Method 2
the reflector in the area of impact is provided with a coating which is reflective until a limit temperature is exceeded and which, if the limit temperature is exceeded, with protective means arranged behind it, which is designed as a beam trap, becomes permeable at least for the laser light and/or itself acts as a beam trap
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to an illumination device (1, 1') for a motor vehicle (17), comprising a laser light source (2), a radiation converter (6) containing a fluorescent material, in particular phosphorus, and a reflector (5), wherein laser light transmitted from the laser light source (2) is converted in the radiation converter (6) into secondary light which is in particular white and has a greater bandwidth by comparison with the laser light, and is spread. Said secondary light is redirected by the reflector (5) into a transmission direction of the illumination device (1, 1'), wherein in an impact region (8) of the reflector (5), which in the absence of the radiation converter (6) is exposed to the laser light, a protective means is provided for reduction of the light intensity of laser light transmitted from the illumination device (1, 1') in the absence of or damage to the radiation converter (6).