Compact Zoom Lens Design with Segmented Groups
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Solution Overview
Problem
There is a demand for a compact and lightweight zoom lens with high optical performance and a large image circle, which existing zoom lenses fail to meet effectively.
Innovation Solution
A zoom lens design comprising a first lens group with negative refractive power, a middle group that includes a front and rear subgroup, and a final group, where the spacing between these groups changes during zooming, and the middle group moves along the optical axis during focusing, while the first and final groups remain stationary, adhering to specific conditional expressions for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a compact and lightweight zoom lens design is implemented, then size and weight are reduced, but optical performance and image circle size may deteriorate
Solution Approach 1:
The zoom lens is divided into multiple lens groups (first lens group with negative refractive power, middle group, and final group) that can move independently during zooming and focusing operations. This segmentation allows each group to be optimized for specific functions while maintaining overall compactness and optical performance.
Solution Approach 2:
The patent employs specific conditional expressions that define optimal parameter ranges for lens group movements, spacing changes, and optical characteristics. By controlling parameters such as the movement distance of the middle group during focusing and the spacing changes between lens groups during zooming, the design achieves both compactness and high optical performance.
2Adaptability or versatility
If lens groups are moved during zooming and focusing, then zoom ratio and focus capability are improved, but device complexity increases
Solution Approach 1:
The middle group serves multiple functions: it moves during zooming to change focal length and moves during focusing to adjust focus distance. The first lens group and final group remain stationary during focusing, simplifying the overall mechanism. This multi-functionality reduces the number of independent moving components while maintaining versatile zoom and focus capabilities.
Solution Approach 2:
The patent implements dynamic spacing between lens groups during zooming operations, where the spacing between the first lens group and middle group changes, as well as the spacing between the middle group and final group changes. This dynamic adjustment enables zoom functionality while maintaining a compact structure through coordinated movement of lens groups.
3Measurement precision
If the middle group moves during focusing while first and final groups remain stationary, then focusing precision is improved, but manufacturing complexity increases
Solution Approach 1:
The focusing function is extracted and assigned specifically to the middle group, which moves along the optical axis as the focus group. The first lens group and final group remain stationary with respect to the image plane during focusing. This extraction simplifies the focusing mechanism by dedicating a single group to focus adjustment, improving focus precision while managing manufacturing 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 solution provides a compact and lightweight zoom lens with high optical performance and a large image circle, achieving reduced size and weight while maintaining high image quality across various zoom and focus settings.
Implementation Method 1
a first lens group that has a negative refractive power
Implementation Method 2
at least a part of the middle group moves along an optical axis as a focus group
Implementation Method 3
During zooming, a spacing between the first lens group and the middle group changes, and a spacing between the middle group and the final group changes
Data Source
AI summary
The zoom lens consists of, in order from an object side to an image side, a first lens group having a negative refractive power, a middle group, and a final group. During zooming, a spacing between the first lens group and the middle group changes, and a spacing between the middle group and the final group changes. During focusing, at least a part of the middle group moves, and the first lens group and the final group remain stationary with respect to an image plane. The zoom lens satisfies predetermined conditional expressions about aback focal length, a focal length, and a maximum half angle of view.