Lens Device Aberration Correction via Moving Lens Group
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lens systems face challenges in correcting aberrations, particularly field curvature, when focus position changes due to variations in imaging distance, zoom position, flange back length, temperature, and aperture diameter, leading to issues with size, weight, and focus sensitivity.
Innovation Solution
A lens device comprising an imaging lens with a focusing lens group and an aberration correction lens group that moves along the optical axis, with a refractive power lower than the focusing lens group, and a controller that adjusts the aberration correction lens group's position relative to the maximum focusing lens group based on changing conditions, ensuring effective aberration correction across various zoom positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the number of lenses constituting the focusing lens group is increased or a floating focus method is adopted to restrain field curvature fluctuation, then the field curvature fluctuation is reduced, but the size and weight of the lens system increase
Solution Approach 1:
The lens system is divided into a focusing lens group and a separate aberration correction lens group. The aberration correction lens group is configured to move independently along the optical axis to correct aberrations, while the focusing lens group handles focusing functions. This segmentation allows each group to be optimized for its specific function, reducing the overall size and weight compared to increasing the number of lenses in the focusing group alone.
Solution Approach 2:
The aberration correction lens group acts as an intermediary element between the focusing lens group and the image plane. It specifically addresses field curvature and other aberrations introduced by the focusing process, allowing the focusing lens group to maintain a simpler, lighter configuration while still achieving optimal optical performance.
2Reliability
If the aberration correction lens group is added to correct aberrations during focusing, then aberration correction is improved, but the device complexity increases
Solution Approach 1:
The aberration correction lens group is designed to move dynamically along the optical axis in response to changes in focusing position and other conditions. This dynamic adjustment allows the system to correct aberrations real-time without requiring a completely complex static multi-group design, thereby managing device complexity while maintaining high aberration correction performance.
Solution Approach 2:
The system corrects aberrations by changing the position parameter of the aberration correction lens group along the optical axis. By adjusting this single critical parameter based on focusing distance and other conditions, the system achieves effective aberration correction without introducing excessive structural complexity into the lens design.
3Measurement precision
If the focusing lens group is moved to correct focus position changes under varying imaging distance and zoom position, then focus accuracy is improved, but field curvature aberration increases
Solution Approach 1:
The lens device incorporates a controller that receives feedback about the focusing position and imaging conditions. Based on this feedback, the controller adjusts the position of the aberration correction lens group to compensate for field curvature aberrations introduced during focusing. This feedback mechanism allows the system to maintain both focus accuracy and aberration correction performance simultaneously.
Solution Approach 2:
The aberration correction lens group serves as an intermediary that specifically addresses the harmful field curvature aberration generated when the focusing lens group moves to correct focus position. By positioning this intermediate lens group at a specific location and adjusting its position dynamically, the system neutralizes the aberration without compromising the focus accuracy achieved by the focusing lens group.
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 enables reduction in size and weight of the lens system while effectively correcting aberrations caused by changes in imaging distance and zoom position, maintaining optimal optical performance across different conditions.
Implementation Method 1
an aberration correction lens group GA that performs aberration correction by moving along an optical axis
Implementation Method 2
focusing is performed by moving a focusing lens group to a predetermined position corresponding to the imaging distance
Data Source
AI summary
The lens device includes an imaging lens and a controller. The imaging lens includes a focusing lens group which moves during focusing and an aberration correction lens group having a refractive power lower than a refractive power of the focusing lens group having the lowest refractive power. The controller adjusts a position of the aberration correction lens group relative to the focusing lens group of which focus sensitivity is maximized according to a changed condition. A predetermined conditional expression related to the focus sensitivity of the focusing lens group is satisfied.