Layered Refractive-Diffractive Lens for Sharp Vehicle Low Beams
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle lenses face challenges with high weight, high cost, and poor optical performance, particularly in ensuring sharpness and preventing aberration of the low-beam cutoff line, due to limitations in design freedom and material properties of glass and plastic lenses.
Innovation Solution
A hybrid refractive-diffractive lens is fabricated using layered injection molding, with refractive-diffractive surfaces symmetrically arranged along the optical axis, incorporating a diffractive structure that accounts for 5-10% of the total dioptre, and optimized edge-to-center thickness ratios to minimize dispersion and aberration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If glass lens with low dispersion is used, then optical performance is improved, but weight and cost increase
Solution Approach 1:
The patent replaces expensive glass lenses with plastic lenses that have lower cost and weight, accepting that plastic materials require different design approaches to achieve comparable optical performance
Solution Approach 2:
The patent uses hybrid refractive-diffractive optical structures combining different optical mechanisms to achieve low dispersion characteristics in plastic lenses, effectively compensating for the inherent limitations of single plastic materials
2Weight of moving object
If plastic lens is used, then weight and cost are reduced, but heat resistance and optical performance deteriorate
Solution Approach 1:
The patent modifies optical parameters by introducing diffractive structures with specific dioptre ratios (5-10% of total dioptre) to compensate for the high dispersion characteristics of heat-resistant plastic materials like PC, achieving acceptable optical performance while maintaining heat resistance
3Ease of manufacture
If diffractive structure is added to reduce edge-center thickness difference, then manufacturability is improved, but design degree of freedom is reduced
Solution Approach 1:
The patent applies diffractive structures selectively at specific locations on the lens surfaces rather than uniformly throughout, allowing different regions to have different optical functions and maintaining design flexibility while improving manufacturability
4Shape
If diffractive structure with high dioptre ratio is used, then edge-center thickness difference is reduced, but aberration of low-beam cutoff line increases
Solution Approach 1:
The patent optimizes the dioptre ratio of diffractive structures to fall within 5-10% of the total lens dioptre, a specific parameter range that balances thickness distribution improvement with aberration control for sharp low-beam cutoff lines
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 lens achieves low dispersion, desirable heat resistance, and ensures sharpness of the low-beam cutoff line while preventing aberration and blurring, with improved manufacturability and reduced weight.
Implementation Method 1
A diffractive grating is formed on the surface of the lens body to phase-shift the wavefront of the light passing through the lens body. The diffractive grating comprises a non-holographic microstructure having a pattern predetermined to cause the light passing through the lens body to generate the predetermined light pattern.
Implementation Method 2
a first refractive-diffractive surface and a second refractive-diffractive surface opposite to each other along an optical axis L are arranged on the lens body
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure relates to the technical field of lenses, and in particular to a lens and a vehicular lamp including the lens. The lens is fabricated in a layered injection molding manner. The lens includes a lens body. A first refractive-diffractive surface and a second refractive-diffractive surface opposite to each other along an optical axis are arranged on the lens body. At least one of the first refractive-diffractive surface and the second refractive-diffractive surface is provided with a diffractive structure rotationally symmetric with respect to the optical axis. A diopter of the diffractive structure accounts for 1-20% of a total diopter of the lens body. The present disclosure can generate a sharp low-beam cutoff line without aberration, saves the product cost, and has desirable heat resistance and application prospect.