Zoom Optical System Aberration Control via Movable Lens Groups
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Solution Overview
Problem
Conventional zoom optical systems face issues with large variations in aberration during zooming and focusing, particularly when capturing short distance objects, and lack effective image blur correction mechanisms.
Innovation Solution
A zoom optical system comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a third lens group with positive refractive power, where at least part of the second or third lens group is movable to correct image blur, and specific conditional expressions are satisfied to optimize focal lengths and aberration correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional zoom optical system is used, then the system structure is simple, but large variations in aberration occur during zooming and focusing
Solution Approach 1:
The optical system is divided into three distinct lens groups with specific refractive power assignments. The first lens group has positive refractive power, the second has negative refractive power, and the third has positive refractive power. This segmentation allows each group to be optimized for specific functions, enabling aberration correction during zooming and focusing operations while maintaining manageable system complexity through modular design.
Solution Approach 2:
The patent implements dynamic movement of the second lens group along the optical axis during zooming operations, and allows the third lens group to move in directions perpendicular to the optical axis for focusing and image blur correction. These dynamic adjustments enable the system to maintain optimal optical performance across different focal lengths and focus distances, reducing aberration variations without requiring a completely complex static structure.
2Manufacturing precision
If the optical system is designed for high image quality, then aberration correction is improved, but the system becomes more complex
Solution Approach 1:
Each lens group is assigned specific local functions with optimized properties. The first lens group handles incoming light with positive refractive power, the second lens group provides negative refractive power for zooming, and the third lens group with positive refractive power handles focusing and aberration correction. This local quality assignment allows high image quality through specialized optimization of each segment rather than requiring the entire system to be overly complex.
Solution Approach 2:
The patent utilizes conditional expressions to control and optimize key parameters including the ratio of focal lengths (f1/f2 and f1/f3) and the refractive powers of the lens groups. By carefully adjusting these parameters within specified ranges, the system achieves high image quality and reduced aberration variations without necessitating excessive structural complexity. The movable components allow dynamic parameter adjustment during operation.
3Manufacturing precision
If an image blur correction mechanism is added, then image quality is improved, but the device complexity increases
Solution Approach 1:
The third lens group serves multiple functions simultaneously: it provides positive refractive power for focusing, corrects image blur through movement in directions perpendicular to the optical axis, and contributes to aberration correction during zooming and focusing operations. This multi-functionality reduces the need for separate dedicated correction mechanisms, thereby improving image quality without proportionally increasing device complexity.
Solution Approach 2:
The image blur correction is achieved through dynamic movement of the third lens group in directions perpendicular to the optical axis. This dynamic adjustment allows the lens group to compensate for image blur caused by camera shake or other factors. The conditional expression governs the movement range and positioning to ensure effective blur correction while maintaining compact system design and avoiding excessive structural complexity.
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 solution achieves reduced aberration variations during zooming and focusing, enhances image quality, and effectively corrects image blur, leading to improved optical performance and size reduction of the optical system.
Implementation Method 1
a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power
Data Source
AI summary
A zoom optical system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, and a third lens group having positive refractive power. The first lens group moves toward an object and air distances between the first to the third lens groups are varied upon zooming from a wide-angle end state to a tele-photo end state. The first lens group comprises a cemented lens consisting of a negative lens and a positive lens in order from the object. The following conditional expressions are satisfied:4.4<f1/(-f2)<8.0.6<f3/fw<3.500.6<(-f2)/f3<1.0530.°<ωw<80.°where f1 denotes a focal length of the first lens group, f2 denotes a focal length of the second lens group, f3 denotes a focal length of the third lens group, fw denotes a focal length of the zoom optical system in the wide-angle end state, and ωw denotes a half angle of view in the wide-angle end state