Vehicular Headlight VCSEL Array Collimation
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Solution Overview
Problem
Vehicular headlights using monolithic array light sources struggle to generate clear light distribution patterns due to the divergence of laser light from surface emitting lasers, which blurs the boundary between irradiated and non-irradiated areas, and limits the brightest illuminance in the irradiation region.
Innovation Solution
Incorporating a lens array with collimator lenses and a prism member to adjust the direction of incident lights from surface emitting lasers, allowing for the formation of a clear light distribution pattern by controlling the overlap of light incident points on an image forming surface, and using a light source controlling unit to individually switch on/off surface emitting lasers based on detected vehicles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If laser light from surface emitting lasers is emitted directly without collimation, then the light can be emitted with simple structure, but the light diverges and the boundary between irradiated and non-irradiated portions becomes blurred, making it difficult to generate a clear light distribution pattern
Solution Approach 1:
The patent divides the light emission control into multiple segments by using a lens array with multiple collimator lenses, where each lens corresponds to a specific surface emitting laser. This segmentation allows independent control of light direction for each laser element, enabling clear light distribution patterns while maintaining manageable structural complexity.
Solution Approach 2:
The patent introduces collimator lenses as intermediary optical elements between the surface emitting lasers and the mask. These collimator lenses mediate the light propagation by converting divergent laser light into parallel beams, thereby enabling precise light distribution without requiring complex direct control mechanisms.
2Manufacturing precision
If the diameter of the opening portion of the mask increases toward the emission side to eliminate dark portions, then the dark portions caused by separation portions between lasers are eliminated, but the divergence of outgoing light is increased, which further hinders the generation of a clear light distribution pattern
Solution Approach 1:
The patent applies preliminary collimation action by using collimator lenses before the light reaches the mask. By pre-aligning the light into parallel beams before it encounters the mask opening, the system eliminates the need to increase the mask opening diameter, thereby preventing subsequent light divergence while still eliminating dark portions.
Solution Approach 2:
The patent introduces dynamic control of light direction by making the collimator lenses adjustable or configurable. This allows the system to adaptively control the parallel beam formation, optimizing the balance between eliminating dark portions and maintaining light directionality under different operating conditions.
3Device complexity
If each irradiation point is irradiated with light from only one corresponding VCSEL, then the structure is simple, but the brightest illuminance in the irradiation region cannot be increased beyond the emission light intensity of a single VCSEL
Solution Approach 1:
The patent merges light from multiple surface emitting lasers by using the lens array to direct and combine their beams onto the same irradiation points. This merging of light sources increases the brightest illuminance beyond what a single VCSEL can provide, while the modular lens array structure keeps the overall system complexity manageable.
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 enables the generation of clear and customizable light distribution patterns with high illuminance regions, effectively addressing the issue of light divergence and enhancing the clarity of the irradiation area.
Implementation Method 1
a lens array in which a plurality of collimator lenses 163 are arranged for outputting incident lights from the respective surface emitting lasers 14 as collimated lights
Implementation Method 2
a prism member 48 configured to adjust a direction of incident lights after passing and output the lights
Implementation Method 3
a mask 20 superimposed on the monolithic array light source 10, and the mask 20 is provided with an opening portion containing a phosphor 22
Data Source
AI summary
Provided is a vehicular headlight that is capable of generating a clear light distribution pattern using a monolithic array light source of surface emitting lasers. The vehicular headlight 1a includes a VCSEL array 5, an image generation unit including a lens array 6 which outputs incident light from the VCSEL array 5 as collimated light so that an image of a light distribution pattern as an illuminance distribution is generated on an output side, a light distribution pattern forming unit 7 having an image forming surface on which the image is formed by the incident light from the image generation unit, and a projection unit 8 outputting the incident light from the light distribution pattern forming unit to an irradiation region in front of the vehicle.