Lighting Fixture Lens Body Managing Chromatic Dispersion
Solution Overview
Problem
The use of polycarbonate or other transparent resin materials in vehicle lighting fixtures leads to chromatic dispersion, causing unintended illumination regions on the upper side of the boundary between light and dark in light distribution patterns due to varying refraction indices with wavelength, which can result in non-compliance with regulatory requirements.
Innovation Solution
A lighting fixture design that incorporates a solid lens body with specific reflecting regions and optical path configurations to manage light refraction and chromatic dispersion, ensuring that light with different wavelengths is distributed correctly, preventing unwanted illumination regions by using a polycarbonate material for the lens body and optimizing the shapes of the incident, reflecting, and exit faces to control refraction and emission directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If polycarbonate material is used for the light guide to achieve high heat resistance, then temperature resistance is improved, but chromatic dispersion increases causing color separation at the boundary of light distribution pattern
Solution Approach 1:
The patent applies local quality by creating different optical paths for different wavelengths within the same light guide structure. By designing the light guide with specific geometric features (such as curved surfaces or internal structures) that differentially affect various wavelengths, the patent achieves localized optimization where shorter wavelengths follow one path and longer wavelengths follow another path, thereby reducing overall chromatic dispersion while maintaining the benefits of polycarbonate material.
Solution Approach 2:
The patent employs dimensionality change by introducing vertical or lateral path separation within the light guide structure. Instead of attempting to correct chromatic dispersion in a single planar dimension, the patent creates three-dimensional optical paths where different wavelengths are directed through different spatial routes, effectively managing chromatic dispersion in multiple dimensions simultaneously while maintaining heat resistance.
2Weight of stationary object
If acrylic material is used to reduce weight, then weight is reduced, but color smear becomes significant at the boundary of light distribution pattern
Solution Approach 1:
The patent applies composite materials by combining polycarbonate (for heat resistance) with other materials or structural elements that have different optical properties. This composite approach allows the light guide to simultaneously achieve high heat resistance from the polycarbonate while using additional materials or structural features to manage chromatic dispersion and prevent color smear, thereby overcoming the limitations of using acrylic alone.
3Ease of manufacture
If light guide structure is simplified to reduce manufacturing complexity, then ease of manufacture is improved, but chromatic dispersion cannot be effectively controlled
Solution Approach 1:
The patent applies parameter changes by optimizing specific geometric parameters of the light guide structure (such as curvature radius, thickness distribution, or internal angle configurations) to control chromatic dispersion. By carefully adjusting these parameters within manufacturable ranges, the patent achieves effective chromatic dispersion management without requiring overly complex manufacturing processes, thereby balancing manufacturing simplicity with 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
The solution effectively prevents the occurrence of unintended illumination regions on the upper side of the boundary between light and dark, ensuring compliance with regulatory requirements and maintaining even light distribution patterns by carefully managing chromatic dispersion and refraction indices.
Implementation Method 1
a reflecting face 106 which is positioned on a more rearward side of the vehicle and which reflects light advanced inside through the incident face 104 forward of the vehicle
Implementation Method 2
the refraction index of the light changes according to the wavelength of the light
Data Source
AI summary
A lighting fixture can include a light source, and a lens body including an incident face through which light emitted from the light source enters the lens body, an exit face, and a reflecting face configured to reflect light which has entered the lens body from the incident face such that the reflected light is emitted from the exit face to form a predetermined light distribution pattern having a boundary line between light and dark. The reflecting face can include a first reflecting region configured to reflect light with a reference wavelength which has entered the incident face perpendicularly with respect to the incident face. A second reflecting region can be configured to reflect light with a wavelength longer than the reference wavelength. A third reflecting region can be configured to reflect light with a wavelength shorter than the reference wavelength.