Vehicle Headlight Lens Array Layout for Heat and Beam Control
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Solution Overview
Problem
Current cylindrical lens array systems for vehicle headlamps have low optical efficiency and are expensive due to the use of glass collimators, with spacing issues leading to overheating of printed circuit boards.
Innovation Solution
An optical system comprising a collimator, cylindrical lens array, and an irregular freeform cylindrical lens array with entry and exit facets of varying sizes, made of thermosetting plastic, to achieve horizontal and vertical light distribution with improved spacing and efficiency, eliminating the need for shutters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If glass collimators are used in cylindrical lens array systems, then optical precision can be maintained, but the system becomes expensive and generates excessive heat causing PCB overheating
Solution Approach 1:
The patent replaces expensive glass collimators with inexpensive plastic collimating lenses. Although plastic has lower thermal conductivity, the design accepts this trade-off by increasing spacing to prevent PCB overheating, prioritizing cost-effectiveness and thermal management over absolute optical precision
Solution Approach 2:
The optical system is divided into multiple plastic collimating lenses arranged in arrays, allowing distributed light collimation. This segmentation enables better heat dissipation across multiple components rather than relying on a single glass collimator, reducing localized thermal buildup on the PCB
2Reliability
If glass collimators are used in cylindrical lens array systems, then optical performance can be maintained, but manufacturing cost increases significantly
Solution Approach 1:
The patent systematically replaces glass collimators with plastic collimating lenses throughout the optical system. Plastic lenses are significantly cheaper to manufacture through injection molding, reducing system cost while maintaining adequate optical performance for automotive headlamp applications
Solution Approach 2:
The patent changes the material parameter from glass to plastic, fundamentally altering the manufacturing process from precision glass working to injection molding. This parameter change dramatically reduces manufacturing cost while the optical design is optimized to compensate for any performance differences
3Productivity
If spacing between LEDs and glass collimators is reduced to less than 0.5 mm, then optical efficiency can be improved, but the printed circuit board becomes excessively hot
Solution Approach 1:
By using plastic collimating lenses instead of glass, the patent enables greater LED-to-lens spacing (1-5 mm) without compromising optical efficiency. The plastic material's lower thermal conductivity and different optical properties allow this spacing increase, effectively decoupling optical performance from thermal management constraints
Solution Approach 2:
The patent uses multiple plastic collimating lenses arranged in arrays, with each lens handling a portion of the LED output. This segmentation allows increased spacing between individual LED-lens pairs while maintaining overall system efficiency, as the distributed architecture prevents heat concentration on the PCB
4Manufacturing precision
If irregular freeform cylindrical lens array is used, then precise light distribution and homogeneity can be achieved, but device complexity increases
Solution Approach 1:
The patent employs an irregular freeform cylindrical lens array where lenses have asymmetric shapes and varying orientations. This asymmetry enables precise control of light distribution patterns, creating homogeneous illumination across the roadway while directing light away from oncoming traffic. The complex geometry is manufactured using injection molding with precision molds
Solution Approach 2:
Different regions of the cylindrical lens array have locally optimized lens characteristics. Lenses in different positions have varying shapes, sizes, and orientations tailored to their specific functional requirements, achieving precise light distribution across different spatial zones of the headlamp beam pattern
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 system achieves optical efficiency greater than 60% while being cost-effective, with enhanced heat management and precise light distribution, ensuring even roadway illumination without blinding oncoming traffic.
Implementation Method 1
The light from the light source, in particular the LEDs, is received in the collimator and collimated to obtain parallel rays
Implementation Method 2
The cylindrical lens array (CLA) is responsible for the horizontal diffusion of the parallel light beams to obtain the desired width of the light distribution
Implementation Method 3
the irregular freeform cylindrical lens array (IFCLA) is configured to generate a light/dark boundary and a gradual vertical light distribution
Implementation Method 4
the irregularly sized entry facets on the entry lens focus light onto the middles of the respective exit facets on the exit lens
Data Source
AI summary
An optical system for a vehicle headlamp is provided, and includes at least one light source, at least one collimator positioned to receive light from the light source, a cylindrical lens array (CLA) positioned to receive collimated light from at least one collimator, and an irregular freeform cylindrical lens array (IFCLA) positioned to receive light from the CLA. The IFCLA includes an entry lens with numerous entry facets of irregular sizes and an exit lens with numerous exit facets. The irregularly sized entry facets on the entry lens focus light onto the middles of the respective exit facets on the exit lens.