Projection Optical System for Vehicle Headlamps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing projection optical systems for vehicle headlamps face challenges in minimizing flare and achieving sufficient brightness, particularly in Adaptive Driving Beam (ADB) light distribution control.
Innovation Solution
A projection optical system comprising a first positive refractive power lens, a second negative refractive power lens, and a third positive refractive power lens, arranged in ascending order. The system is designed to reduce comatic aberration and flare by optimizing the refractive power distribution and center thickness of the second lens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a projection optical system is designed to minimize flare, then the accuracy of ADB light distribution control is improved, but the brightness of the system deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the refractive powers of individual lenses (P1, P2, P3) and their relationships (e.g., P2/P1 ratio between -0.5 and -0.1, P3/(P1+P2) ratio between 0.8 and 1.5). These parameter optimizations enable the system to simultaneously achieve low flare (high measurement precision) and high brightness by carefully balancing the optical parameters of the three-lens configuration
2Object-generated harmful factors
If the refractive power distribution is optimized to reduce comatic aberration, then flare is minimized, but the system complexity increases
Solution Approach 1:
The patent applies local quality by assigning different refractive power characteristics to each lens element. The first lens has positive refractive power, the second has negative refractive power, and the third has positive refractive power. Each lens is optimized with specific refractive power ratios (P2/P1, P3/(P1+P2)) to locally address comatic aberration and flare issues, achieving overall system optimization without excessive complexity
Solution Approach 2:
The patent segments the projection optical system into three distinct lens elements with different refractive power characteristics. This segmentation allows each lens to be independently optimized for specific functions: the first lens for initial light convergence, the second for aberration correction with negative power, and the third for final focusing. This segmentation enables effective control of flare and comatic aberration while maintaining manageable system complexity
3Object-generated harmful factors
If the center thickness of the second lens is increased to control aberration, then comatic aberration is reduced, but the loss of light increases
Solution Approach 1:
The patent applies parameter changes by establishing an optimized center thickness range for the second lens (0.5mm to 2.0mm) and correlating it with the refractive power ratios. This parameter optimization ensures that the second lens is thick enough to effectively control comatic aberration through its negative refractive power, but not so thick as to cause excessive light absorption or scattering, thereby minimizing energy loss while achieving aberration correction
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 effectively reduces flare and comatic aberration, while maintaining sufficient brightness, thereby improving the accuracy of ADB light distribution control and illuminating a wider area.
Implementation Method 1
a first lens having a positive refractive power, a second lens having a negative refractive power and a third lens having a positive refractive power, the lenses being arranged in ascending order in number from the side of an illuminated object
Data Source
AI summary
A projection optical system comprising a first lens having a positive refractive power, a second lens having a negative refractive power and a third lens having a positive refractive power, the lenses being arranged in ascending order in number from the side of an illuminated object, wherein when the optical system is regarded as an imaging optical system receiving a light beam from the side of the illuminated object, the effective focal length is represented by f, the total refractive power is represented by Pt=1/f, each lens surface of the three lenses are referred to as a first lens surface to a sixth lens surface from the side of the illuminated object, the refractive power is represented by Pt, the center thickness of the second lens is represented by L2 and f number is represented by F, the expressions1.3<P5/Pt0.1<L2/f<0.25F<0.7