Projection Headlamp Cutoff Control for Glare and Visibility
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Solution Overview
Problem
Existing vehicle headlamps struggle to form a low beam light distribution pattern with a clearly defined cutoff line that prevents glare to drivers of preceding or oncoming vehicles while maintaining good visibility, and the glare issue persists due to varying vehicle attachment positions and relationships.
Innovation Solution
A vehicle headlamp design incorporating a projection lens, a light source positioned behind its rear focal point, and an optical member with a shade and reflective portion that controls light emission to create a sharp cutoff line for one lane and a blurred cutoff line for the other, using a movable reflective portion to adjust based on vehicle positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a clearly defined cutoff line is formed to prevent glare, then glare prevention is improved, but visibility is worsened
Solution Approach 1:
The optical member is divided into multiple functional regions: a first optical region with a sharp cutoff line to prevent glare to oncoming vehicles, and a second optical region with a blurred cutoff line to improve visibility for the host vehicle lane. This segmentation allows different parts of the headlamp to serve different purposes simultaneously.
Solution Approach 2:
Different regions of the light distribution pattern are given different qualities: the region toward oncoming vehicles has a sharp, well-defined cutoff line to minimize glare, while the region toward the host vehicle lane has a blurred cutoff line to enhance visibility. Each region's optical properties are optimized for its specific function.
2Object-affected harmful factors
If a clearly defined cutoff line is formed, then glare prevention is improved, but adaptability to different vehicle positions is worsened
Solution Approach 1:
The headlamp system incorporates movable optical members that can adjust their positions dynamically. This allows the cutoff line characteristics (sharp or blurred) to be adaptively changed based on the relative positions of the host vehicle, preceding vehicles, and oncoming vehicles, enabling the system to maintain optimal glare prevention and visibility under varying driving conditions.
Solution Approach 2:
The system uses detection means to monitor the positions of preceding and oncoming vehicles, and based on this feedback information, the control means adjusts the optical members to appropriate positions. This closed-loop control ensures the headlamp adapts to different vehicle configurations and maintains effective glare prevention while preserving visibility.
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 headlamp effectively prevents glare to oncoming vehicles by forming a sharp cutoff line for the host vehicle lane and improves visibility by blurring the cutoff line for the opposite lane, enhancing safety and visibility in various driving conditions.
Implementation Method 1
a reflective portion that extends from the shade toward the projection lens and reflects a portion of the light emitted from the light source toward the projection lens
Implementation Method 2
a projection lens, a light source arranged behind a rear focal point of the projection lens
Data Source
AI summary
A vehicle headlamp includes a projection lens, a light source arranged behind a rear focal point of the projection lens, and an optical member that controls light emitted from the light source. The optical member includes a shade that is located near the rear focal point of the projection lens and shields a portion of the light emitted from the light source to form a cutoff line of a light distribution pattern, and a reflective portion that extends from the shade toward the projection lens and reflects a portion of the light emitted from the light source toward the projection lens to irradiate a region overlapping the cutoff line with the light.