Laser Light Guide for Vehicle Lamp Cutoff Clarity
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Solution Overview
Problem
Vehicle lamps using laser light sources face challenges in achieving high brightness and uniform illuminance over long distances due to Gaussian light intensity distributions, leading to blurry cutoff lines and reduced visibility, while conventional solutions like light shields lower light utilization efficiency.
Innovation Solution
A laser light source device that employs a light guide with a lateral face parallel to the optical axis, causing total reflection of laser light and overlaying it on a fluorescent member to enhance brightness at the emission area's end, resulting in a beam spot with increased light intensity towards the cutoff line, thereby improving long-distance visibility without reducing light utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light shield member such as a shade is provided in front of the light source to shut off part of light, then the bright/dark boundary becomes clearer, but the light utilization efficiency is significantly lowered
Solution Approach 1:
The patent applies local quality by creating a non-uniform light intensity distribution that is specifically optimized for different spatial regions. The light guide structure generates higher light intensity at the end corresponding to the cutoff line position, while maintaining appropriate intensity at other areas. This localized intensity enhancement eliminates the need for light shields while achieving clear bright/dark boundaries and maintaining overall light utilization efficiency.
Solution Approach 2:
Instead of using a light shield to block excess light from the high-intensity center region, the patent inverts the approach by using a light guide to selectively redirect and concentrate light toward the cutoff line region. The light guide's lateral face reflects light at specific angles to enhance intensity where needed, transforming the problem from light blocking to light directing, thereby maintaining light utilization efficiency while achieving the desired brightness distribution.
2Device complexity
If conventional laser diodes with Gaussian light intensity distribution are used, then the light source structure is simple, but the illuminance at distant road surface is low and the cutoff line is blurry
Solution Approach 1:
The patent introduces a light guide as an intermediary component between the conventional laser diode and the optical system. The light guide receives light from the simple laser diode source and transforms its intensity distribution through total internal reflection at the lateral face. This intermediary structure maintains the simplicity of the light source while producing the desired non-uniform intensity pattern that enhances distant road surface illuminance and sharpens the cutoff line.
Solution Approach 2:
The patent changes the light intensity distribution parameter from a standard Gaussian profile to a customized profile with enhanced intensity at specific regions. By controlling the light guide's geometry and the angle of total internal reflection, the system transforms the light parameters to achieve higher intensity at the cutoff line region, thereby improving distant visibility without complicating the overall light source structure.
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 enhances light intensity at the cutoff line, creating a more distinct bright/dark boundary and improving long-distance visibility, maintaining high light utilization efficiency without the need for light shields, thus ensuring safer nighttime driving.
Implementation Method 1
When laser light from the light source propagates through the light guide, the laser light is reflected by a lateral face of the light guide parallel to the optical axis by total reflection.
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3B
AI summary
In an exemplary embodiment, a laser light source device includes a laser light source that emits laser light from a laser emission aperture. The laser light source device also includes a condenser lens disposed in front of the laser light source in a laser emission direction to collect the laser light. The laser light source device also includes a fluorescent member disposed in front of the condenser lens in the laser emission direction to receive the laser light collected by the condenser lens and to emit light of a different wavelength from that of the laser light. The laser light source device also includes a light guide that forms a light path of laser light from the laser light source to the condenser lens.