Structured Optical Surface for Tolerant Headlight Light Scattering
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Solution Overview
Problem
Existing optical components for motor vehicle illuminating devices, such as headlights, face challenges in achieving precise scattering effects to soften edges and reduce inhomogeneities in light distribution due to manufacturing tolerances, leading to unsatisfactory cutoff lines and potential double cutoffs.
Innovation Solution
A method involving the generation of a virtual representation of a surface with a grid of points that are randomly shifted parallel to the surface normals, creating a structured surface with randomly distributed depressions and elevations, which can be produced using NURBS surfaces for CAD-based manufacturing, resulting in improved light scattering and reduced manufacturing tolerance sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a mathematically precisely described geometric shape (such as sinusoidal microstructures) is used for surface structuring, then the scattering effect can be controlled, but very precise manufacturing is required and small deviations lead to unsatisfactory results
Solution Approach 1:
The patent applies asymmetry by using a randomized point distribution instead of a symmetric, mathematically precise geometric pattern. The points are shifted randomly in the z-direction according to a statistical distribution, creating an asymmetric microstructure that is less sensitive to manufacturing variations. This randomized asymmetric structure maintains the desired scattering effect while reducing sensitivity to precision deviations.
Solution Approach 2:
The patent changes the parameter approach from fixed geometric dimensions to statistical distribution parameters. Instead of specifying exact sinusoidal amplitudes and wavelengths, the invention defines the microstructure by statistical parameters (mean, variance) of the randomized point positions. This parameter transformation makes the system more robust to manufacturing tolerances while maintaining consistent optical performance.
2Illumination intensity
If a structured surface with precise geometric shapes is used, then scattering effects can be produced, but local defects can lead to jumps in the intensity curve and high AK-31 values
Solution Approach 1:
The patent applies homogeneity by ensuring that the randomized points are distributed according to a consistent statistical distribution across the entire surface. This statistical homogeneity ensures that the scattering effect is uniform across the surface, preventing local defects from creating intensity jumps. The consistent statistical properties throughout the structure guarantee smooth intensity curves and reliable AK-31 values.
3Manufacturing precision
If mathematical precision is prioritized in surface structuring, then the desired scattering effect can be achieved, but manufacturing tolerances become critical and production becomes more difficult
Solution Approach 1:
The patent effectively replaces the need for expensive, high-precision manufacturing processes with a design that tolerates ordinary manufacturing variations. By using a randomized statistical structure rather than a precise geometric pattern, the invention makes the manufacturing process less critical, allowing standard manufacturing tolerances to be used without compromising the optical performance.
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 approach achieves a better statistical distribution of light scattering angles, blurs the cutoff line, and helps conceal color effects, leading to a more reproducible and tolerant production of optical components that enhance the light distribution in motor vehicle illuminating devices.
Implementation Method 1
By structuring at least one surface of an optical component of the illuminating device, scattering effects can be produced to soften edges imaged over the optical component or to reduce inhomogeneities in a light distribution
Data Source
AI summary
A method for producing an optical component for an illuminating device of a motor vehicle, the optical component having at least one structured surface, comprising the following method steps: generating a first virtual representation of the surface that is to be structured of the component, applying a grid of points to the virtual representation of the surface that is to be structured of the component, shifting all or a plurality of the points in a randomized manner in the positive or negative direction in parallel with the respective normals to the surface in order to structure the surface, creating a second virtual representation of the surface that reproduces the structuring achieved by the shifting of the points, and producing the component on the basis of the second virtual representation of the surface.