Compact Retrofocus Lens System with Aberration Correction
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Solution Overview
Problem
Conventional retrofocus wide-angle lenses have a large total lens length, which makes them less compact and difficult to correct various aberrations effectively.
Innovation Solution
A lens system configuration comprising a negative meniscus lens, a cemented lens component with positive refractive power, a negative refractive power lens, a positive refractive power lens, and a sixth lens with positive refractive power, where specific conditional expressions are satisfied to optimize the lens system's design, including the placement of an aperture stop and aspherical surfaces, to achieve compactness and superior optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional retrofocus lens configuration is used, then wide-angle optical performance is achieved, but the total lens length becomes large
Solution Approach 1:
The lens system is divided into five distinct lens groups (first through sixth lenses) with specific positive and negative refractive powers arranged in a particular sequence. This segmentation allows each lens to contribute differently to the overall optical performance, enabling compact design while maintaining aberration correction capability through optimized distribution of refractive functions across multiple elements
Solution Approach 2:
Each lens in the system is designed with specific local optical properties: the first lens has negative refractive power with a convex object-side surface, the second lens has positive refractive power, the third lens has negative refractive power, and so on. This local differentiation of optical characteristics enables precise control over light paths and aberrations while maintaining a compact overall structure
2Volume of moving object
If the lens system is made compact, then the total lens length is reduced, but aberration correction becomes more difficult
Solution Approach 1:
The patent specifies precise parameter ranges for each lens including refractive powers (positive or negative), surface curvatures, and axial positions. By carefully controlling these parameters within defined ranges, the system achieves both compact dimensions and high precision aberration correction. The conditional expressions establish quantitative relationships that ensure optimal performance while maintaining compact form factor
Solution Approach 2:
The lens system employs a cemented lens structure where the second lens (positive refractive power) and third lens (negative refractive power) are optically cemented together to form a composite lens component. This composite structure enables sophisticated aberration correction through the interaction of different glass materials with complementary optical properties, achieving high precision correction in a compact configuration
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 system achieves a compact design with excellent aberration correction, including barrel type distortion, spherical aberration, and astigmatism, while maintaining a compact form factor.
Implementation Method 1
A lens system comprises, in order from an object side: a first lens constructed by a negative meniscus lens having a convex surface facing the object side; a cemented lens component having positive refractive power as a whole constructed by a second lens having positive refractive power cemented with a third lens having negative refractive power; a fourth lens having negative refractive power; a fifth lens having positive refractive power; and a sixth lens having positive refractive power
Data Source
AI summary
With comprising, in order from an object side: a first lens L1 constructed by a negative meniscus lens having a convex surface facing the object side; a cemented lens component CL1 having positive refractive power as a whole constructed by a second lens L2 having positive refractive power and a third lens L3 having negative refractive power; a fourth lens L4 having negative refractive power; a fifth lens L5 having positive refractive power; and a sixth lens L6 having positive refractive power, and the following expression being satisfied: 0.01<d2/(-f1)<0.15 where d2 denotes a distance along an optical axis between the first lens and the second lens, and f1 denotes a focal length of the first lens, a compact lens system having superb optical performance with correcting various aberrations, a wide-angle lens, an optical apparatus equipped therewith, and a method for manufacturing the lens system are provided.