Variable-Aperture Optical Layout for Large Image Circles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical systems struggle to achieve a large image circle with small size and effective aberration correction, which are increasingly demanded in optical apparatuses.
Innovation Solution
An optical system design with specific lens configurations and movements, including variable aperture stops, cemented lenses, and refractive power distributions, adhering to conditional expressions to optimize image quality and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the optical system uses a compact lens configuration with limited elements, then the size is reduced, but the image circle becomes small and aberration correction deteriorates
Solution Approach 1:
The optical system is divided into multiple lens groups (first lens group with negative refractive power, second lens group with positive refractive power, third lens group with negative refractive power) that can move independently during focusing. This segmentation allows each group to be optimized for specific functions while maintaining compact overall size, resolving the contradiction between small size and large image circle.
Solution Approach 2:
The patent employs dynamic focusing mechanisms where lens groups move along the optical axis to adjust focus. The first lens group moves when focusing on nearby objects, while the second and third lens groups remain stationary. This dynamic configuration allows the system to maintain a compact form factor while achieving extended depth of field and preserving image quality across the entire image circle.
2Reliability
If more lens elements are added to correct aberrations, then aberration correction improves, but the system size increases
Solution Approach 1:
Each lens group is designed with specific refractive power characteristics tailored to its position and function. The first lens group has negative refractive power for correcting specific aberrations during close-up focusing, while the second lens group has positive refractive power for overall focal length adjustment. The third lens group has negative refractive power for additional aberration correction. This localized optimization of optical properties achieves superior aberration correction without requiring a uniform increase in the number of lens elements throughout the system.
3Adaptability or versatility
If the aperture stop is positioned differently or has variable opening diameter, then the F number control improves, but the aberration correction and image circle are affected
Solution Approach 1:
The aperture stop is designed with variable opening diameter that can be adjusted to control the F number of the optical system. This multi-functional aperture stop serves both as an iris for light control and as an aberration correction element. By coordinating the aperture stop's variable opening with the movement of lens groups during focusing, the system achieves adaptable F number control while maintaining effective aberration correction across different focusing distances and aperture settings.
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 an optical system with a large image circle, small size, and well-corrected aberrations, enhancing performance in optical apparatuses.
Implementation Method 1
an optical system comprising: an aperture stop that has a variable opening diameter and that determines an F number of the optical system, in which at least one positive lens and at least one negative lens are disposed closer to an object side than the aperture stop
Data Source
AI summary
An optical system includes an aperture stop that has a variable opening diameter and that determines an F number of the optical system, in which at least one positive lens and at least one negative lens are disposed closer to an object side than the aperture stop, and at least one positive lens and at least one negative lens are disposed closer to an image side than the aperture stop. An image side surface of at least one negative lens among the negative lenses disposed closer to the object side than the aperture stop has a concave shape. The optical system satisfies a predetermined conditional expression.