Imaging Lens Wide Angle Low Distortion Design
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Solution Overview
Problem
Existing imaging lenses for factory automation, machine vision, and surveillance cameras face challenges in achieving a wide angle with small distortion and a low F-Number, as previous lens systems either have insufficient angle of view, high distortion, or insufficiently small F-Number.
Innovation Solution
An imaging lens configuration comprising a first lens group and a second lens group with specific refractive powers and surface curvatures, including a 1-1st negative meniscus lens, a 1-2nd negative lens, a 1-3rd positive biconvex lens, a 1-4th negative meniscus lens, and a 1-5th positive lens, optimized by conditional expressions to achieve small distortion and a wide angle with a small F-Number.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a conventional lens system is used, then the structure is simple, but the angle of view is not sufficiently wide and the F-Number is not sufficiently small
Solution Approach 1:
The lens system is divided into multiple lens groups (first lens group with five lenses, second lens group with positive refractive power) where each group has specific functions. The first lens group handles wide-angle light gathering while the second lens group corrects aberrations, allowing the system to achieve both wide angle of view and small F-Number without excessive complexity in any single component.
Solution Approach 2:
The patent introduces a specific spatial arrangement dimension by positioning the aperture stop between the two lens groups and specifying exact curvature relationships between adjacent lenses. This dimensional positioning enables the system to achieve wide angle and small F-Number simultaneously by controlling light paths in three-dimensional space rather than relying on single-parameter optimization.
2Area of moving object
If the angle of view is increased, then the field of view is wider, but distortion increases
Solution Approach 1:
Different regions of the lens system are assigned different functional qualities: the first lens group (especially the negative meniscus lenses) is optimized for wide-angle light gathering, while the second lens group is specifically designed for distortion correction. The aperture stop is positioned at a specific location to control off-axis light rays and minimize barrel distortion inherent in wide-angle systems.
Solution Approach 2:
The patent employs precise parameter specifications including curvature radius ratios (e.g., R1/R2 between -0.8 and -0.2), focal length relationships (f1/f between -5.0 and -1.0), and spacing parameters (D8/f between 0.3 and 1.5). These parameter changes enable the system to maintain low distortion while achieving wide angle of view by mathematically optimizing the optical path.
3Use of energy by moving object
If the F-Number is reduced, then more light is gathered, but spherical aberration increases
Solution Approach 1:
The aperture stop acts as an intermediary element positioned between the two lens groups. It controls the cone angle of light rays passing through the system, blocking extreme marginal rays that would cause spherical aberration while still allowing sufficient light to pass through the center regions of the lenses to maintain a small effective F-Number and good light gathering capability.
Solution Approach 2:
The patent uses composite lens design combining different lens types (negative meniscus, positive biconvex, negative concave) with specific refractive index and Abbe number combinations. This composite approach allows the system to achieve small F-Number with controlled spherical aberration by having different lens elements contribute differently to the overall wavefront 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 proposed lens configuration effectively suppresses distortion and spherical aberration while maintaining a wide angle and small F-Number, enhancing image quality for applications like factory automation and machine vision.
Implementation Method 1
a first lens group G1, an aperture stop St, and a second lens group G2 having a positive refractive power, in order from an object side
Data Source
AI summary
The imaging lens consists of a first lens group G1, an aperture stop St, and a positive second lens group G2, in order from an object side. The first lens group G1 consists of a 1-1st negative meniscus lens L11 with its convex surface toward the object side, a 1-2nd negative lens L12 with its concave surface toward an image side, a 1-3rd positive lens L13 having a biconvex shape, a 1-4th negative meniscus lens L14 with its convex surface toward the object side, and a 1-5th positive lens L15 with its convex surface toward the object side, in order from the object side. Predetermined conditional expressions are satisfied which relate to a focal length of the whole system, a focal length of the first lens group G1, and a distance on an optical axis between the 1-4th negative meniscus lens L14 and the 1-5th positive lens L15.