Wide-Angle Imaging Lens with Segmented Front and Rear Groups
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging lenses for on-board and surveillance cameras have limited angles of view and F numbers, and struggle with aberration correction, making them inadequate for capturing wide-angle, high-quality images with small F numbers.
Innovation Solution
A wide-angle imaging lens configuration comprising a front group with negative and positive refractive power lenses, and a rear group with strategically arranged positive and negative refractive power lenses, optimized by specific focal length and air gap ratios to achieve a wider angle of view and improved aberration correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If a conventional imaging lens configuration is used, then the lens structure is simple, but the angle of view is limited (67°-69°) and cannot capture wide area images
Solution Approach 1:
The imaging lens is divided into two distinct groups: a front group (with negative refractive power) and a rear group (with positive refractive power). This segmentation allows each group to perform specific optical functions, enabling a wider angle of view while maintaining manageable structural complexity through functional division.
Solution Approach 2:
The patent applies parameter changes by specifying precise focal length relationships (fF/f and fR/f ratios) and air gap dimensions (D34/f ratio) to optimize the optical performance. These parameter adjustments enable the lens to achieve a wider angle of view (100° or more) while controlling aberrations through mathematical optimization.
2Illumination intensity
If the F number is reduced to capture brighter images, then image brightness improves, but aberration correction becomes more difficult
Solution Approach 1:
The patent applies local quality by assigning specific refractive power characteristics to different lens groups: the front group has negative refractive power to control light convergence and reduce spherical aberration, while the rear group has positive refractive power to focus light and correct field curvature. This localized functional assignment enables effective aberration correction at small F numbers.
Solution Approach 2:
The patent uses parameter changes by optimizing the focal length ratios (fF/f and fR/f) and air gap dimensions (D34/f) to achieve the desired balance between brightness and aberration correction. These precise parameter specifications enable the system to maintain high image quality at reduced F numbers.
3Manufacturing precision
If more lenses are added to correct aberrations, then aberration correction improves, but the lens size and complexity increase
Solution Approach 1:
The patent segments the lens system into two functional groups with opposite refractive powers, allowing effective aberration correction through the interaction between these groups rather than requiring numerous individual lenses. This segmentation achieves superior aberration control with a compact eight-lens configuration.
Solution Approach 2:
The patent applies the counterweight principle by using the front group with negative refractive power to counterbalance the aberrations introduced by the rear group with positive refractive power. This mutual compensation between opposing groups enables effective aberration correction while maintaining a compact overall structure.
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 enables the capture of high-quality, bright images with a wider angle of view, effectively correcting various aberrations and reducing the lens system's size while increasing the angle of view beyond existing limitations.
Implementation Method 1
a first lens L1 that is convex toward the object side and has a negative refractive power
Implementation Method 2
a third lens L3 that has a positive refractive power
Implementation Method 3
capable of satisfactorily correcting various aberrations
Data Source
AI summary
Provided are an imaging lens and an Imaging apparatus which includes this imaging lens. The imaging lens consists of, in order from an object side: a front group GF; a diaphragm St; and a rear group GR. The front group GF consists of, in order from the object side: a first lens L1 that is convex toward the object side and has a negative refractive power; a second lens L2 that has a negative refractive power; and a third lens L3 that has a positive refractive power. The rear group GR consists of, in order from the object side: a fourth lens L4 that has a positive refractive power; a fifth lens L5 that has a positive refractive power; a sixth lens L6 that has a negative refractive power; a seventh lens L7 that has a positive refractive power; and an eighth lens L8 that has a negative refractive power.