Vehicle Light Guide Deflection Surface for Horizontal Cut-Off Lines
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Solution Overview
Problem
Existing lighting devices for vehicles experience imaging errors, particularly distortion, as the cut-off line in the light distribution becomes inclined or bent downwards with increasing lateral distance from the optical axis, leading to insufficient light emission in the desired areas.
Innovation Solution
The upper light deflection surface in the lighting device is modified by introducing regions laterally offset from the vertical longitudinal plane, with varying shapes that increase the average inclination of intersection curves, ensuring light rays are reflected differently to compensate for imaging errors, maintaining a straight cut-off line even at greater lateral distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional light guide body with a standard upper light deflection surface is used, then the device structure is simple, but imaging errors occur causing the cut-off line to become inclined or bent downwards with increasing lateral distance from the optical axis
Solution Approach 1:
The upper light deflection surface is divided into multiple regions (first region, second region, third region) with different inclination characteristics. The first region has a first inclination, the second region has a second inclination different from the first, and the third region has a third inclination different from the second. This local differentiation allows each region to compensate for imaging errors in its specific lateral distance range, maintaining a horizontal cut-off line across the entire light distribution while keeping the overall structure relatively simple.
2Reliability
If the upper light deflection surface is modified with multiple inclination regions to compensate for imaging errors, then the cut-off line remains horizontal across the field of view, but the manufacturing complexity increases
Solution Approach 1:
The upper light deflection surface is segmented into multiple distinct regions (first, second, and third regions) along the lateral direction from the optical axis. Each region is defined by specific inclination characteristics that compensate for imaging errors at different lateral distances. This segmentation allows the complex compensation function to be broken down into manageable zones, each with relatively simple geometric characteristics, facilitating manufacturing while achieving the desired optical performance.
3Shape
If light rays are reflected at steeper angles in lateral regions to compensate for distortion, then the cut-off line remains horizontal, but the light emission intensity in certain areas may be affected
Solution Approach 1:
The inclination parameter of the upper light deflection surface is systematically changed across different lateral regions. The first region has a first inclination parameter, the second region has a second inclination parameter different from the first, and the third region has a third inclination parameter different from the second. This parameter variation is specifically designed to compensate for imaging errors at different lateral distances while maintaining appropriate light emission intensity. The projection optics device is also configured with specific parameters to work in conjunction with these inclination changes, ensuring optimal light distribution.
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 modified deflection surface ensures that light rays are reflected and imaged correctly, maintaining a horizontal cut-off line and adequate light emission across the desired field of view, minimizing distortion and ensuring uniform light distribution.
Implementation Method 1
Light emitted by the light source travels through the light guide body mainly via total internal reflection to the light exit surface
Implementation Method 2
a projection optics device, for example a projection lens, with an optical axis and a focal point
Data Source
AI summary
A lighting device (1) for a vehicle, particularly a motor vehicle, comprises at least one light source (10) configured to emit light, a transparent light guide body (100), at least one light coupling area (101) to couple light from the light source (10) into the light guide body (100), and a projection optics device (200) with an optical axis (X) and a focal point (F). The light guide body (100) has an upper light deflection surface (102), a light exit surface (104), and a lower light deflection surface (103). The light travels through the guide body (100), deflects between surfaces (102) and (103), and exits via the exit surface (104). Regions (BE; BE1; BE1′ . . . BE10′) of the upper light deflection surface (102) deviate in shape from the vertical longitudinal plane (LE), resulting in intersection curves (SK1, SK2, SK3; SK1′, SK2′, SK3′) with greater average inclinations (α1, α2) than the longitudinal axis intersection curve (SK0).