Zoom Optical System Aberration Control via Lens Group Segmentation
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Solution Overview
Problem
Conventional zoom optical systems for cameras have a narrow angle of view at the wide-angle end and exhibit large variations in aberration during zooming, which affect optical performance.
Innovation Solution
A zoom optical system comprising a first lens group with negative refractive power, a second lens group with positive refractive power, and a rear lens group, where the lens groups move relative to each other upon zooming, with specific focal length ratios and conditional expressions to optimize optical performance, including the use of aspherical surfaces and coordinated movement of lens groups to reduce aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional zoom optical system configuration is used, then the structure is simple, but the angle of view is narrow at wide-angle end and aberration variation is large
Solution Approach 1:
The zoom optical system is divided into multiple lens groups (first lens group with negative refractive power, second lens group with positive refractive power, and rear lens group) that can move independently during zooming. This segmentation allows each group to contribute differently to the overall optical performance, enabling wider angle of view while controlling aberration variation through coordinated movement of the groups.
Solution Approach 2:
Different lens groups are assigned specific refractive powers (negative for first group, positive for second group) and specific movement characteristics during zooming. The F lens group within the rear lens group has particular properties that allow it to move upon focusing while maintaining aberration control. This local differentiation of optical properties enables simultaneous achievement of wide angle of view and stable aberration characteristics.
2Manufacturing precision
If lens groups move during zooming to improve optical performance, then imaging quality improves, but the mechanical complexity increases
Solution Approach 1:
The lens groups are configured to move dynamically during zooming operations, with the first lens group moving in one direction and the second lens group moving in the opposite direction. The rear lens group, including the F lens group, also moves during focusing operations. This dynamic configuration allows the system to maintain optimal optical performance across different focal lengths while using relatively simple mechanical movement patterns.
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 achieves higher optical performance with a wider angle of view at the wide-angle end and reduced aberration variation during zooming, ensuring excellent imaging quality across focal lengths.
Implementation Method 1
a first lens group having negative refractive power, a second lens group having positive refractive power
Data Source
AI summary
A zoom optical system consists of a first lens group having negative refractive power, a second lens group having positive refractive power, and a rear lens group which are disposed in order from an object. The rear lens group comprises a last lens group and an F lens group in order from a side closest to an image. Lens groups forming the first lens group, the second lens group, and the rear lens group are configured in such a manner that, upon zooming, the respective lens groups move and a distance between the lens groups adjacent to each other changes. At least a part of the F lens group is configured to move upon focusing. Further, the following conditional expression is satisfied.−0.220<f1/fE<0.280where f1: a focal length of the first lens group, andfE: a focal length of the last lens group