Vehicle Headlight Secondary Lens Edge Rounding
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Solution Overview
Problem
Existing vehicle headlight designs suffer from undesirable effects such as sharp edges in the light image, resulting in stripes of different colors and luminance due to the imaging of boundary edges, which lead to a disruptive and annoying bright light line.
Innovation Solution
The implementation of edge rounding in the transition region between the upper/lower boundary surface and the front light exit surface, ensuring G1-continuous or G2-continuous curvature, effectively smoothes the light distribution and avoids the formation of sharp light lines by acting as a defocusing lens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If flat boundary surfaces are used in the secondary lens, then the manufacturing is simplified and the structure is easier to produce, but sharp edges are formed in the light image causing stripes of different colors and luminance
Solution Approach 1:
The patent applies curvature by replacing the flat boundary surfaces with continuously curved surfaces that have G1 or G2 continuity. The boundary surfaces are designed with specific radius of curvature values (e.g., 5mm, 10mm, 15mm) to eliminate sharp edges while maintaining optical performance. This curved transition prevents the formation of sharp light lines and color stripes in the projected light image.
Solution Approach 2:
The patent changes the geometric parameters of the boundary surfaces by introducing continuous curvature with specific radius values. The G1 or G2 continuity requirement ensures smooth transitions between different lens surfaces, fundamentally altering the surface geometry from flat/angular to continuously curved, thereby eliminating the harmful sharp edges in the optical image.
2Illumination intensity
If edge rounding with G1 or G2 continuity is implemented, then the light distribution becomes soft and uniform without sharp light lines, but the manufacturing precision requirements increase
Solution Approach 1:
The continuously curved boundary surfaces with G1 or G2 continuity provide smooth light distribution by eliminating abrupt geometric transitions. The specific radius of curvature values are optimized to achieve uniform illumination while avoiding sharp light lines, balancing optical performance with manufacturability.
Solution Approach 2:
By specifying particular radius of curvature ranges and continuity requirements (G1 or G2), the patent transforms the manufacturing challenge into a controlled precision requirement. These parameter specifications enable manufacturers to achieve the desired smooth light distribution through controlled curvature rather than complex freeform surfaces.
3Object-generated harmful factors
If the boundary surfaces are made continuously curved, then the sharp light lines are eliminated, but the device complexity increases due to more complex surface geometry
Solution Approach 1:
The patent employs continuously curved boundary surfaces with G1 or G2 continuity to eliminate sharp light lines. The curvature is applied specifically to the boundary surfaces between the light exit surface and the side surfaces, maintaining simplicity in other areas of the lens design while achieving the desired optical effect.
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 results in a soft and uniform light distribution, eliminating the bright and annoying light line, while allowing for the adjustment of the upper limit of the illuminated image, thereby enhancing the overall light image quality.
Implementation Method 1
an edge rounding is provided, the surface of which is G1-continuous, the radius of curvature in the range of 2 to 30% the radius of curvature of the light exit surface of the at least one secondary lens... acts as a defocusing lens
Data Source
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AI summary
The invention relates to a headlight (1) for vehicles, comprising at least one primary optical element (2) having at least one light exit surface (6), at least one secondary lens (3) associated with the at least one primary optical element for imaging the at least one light exit surface as a light image onto the road, wherein the at least one secondary lens has a preferably aspherical front light exit surface (15), a rear of light entry surface (14), and substantially planar boundary surfaces (10, 11, 12, 13) between the front light exit surface and the rear light entry surface. In said headlight a rounded edge (27, 30), the surface of which is G2-constant, is provided in the junction region of an upper and/or lower boundary surface (10, 11) and the front light exit surface (15), wherein the average radius of curvature (r1, r2) is in a range from 2 to 30 % of the radius of curvature (R) of the light exit surface (15) of the at least one secondary lens. The rounded edge (27, 30) in the junction region of the upper and/or lower boundary surface (10, 11) and the front light exit surface (15) is preferably at least G1-constant or G2-constant.