Zoom Lens Aberration Correction via Three-Group Movement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional zoom lenses do not achieve ideal optical performance with a wide-angle of view, large aperture ratio, and high zoom ratio, which are essential for digital still cameras.
Innovation Solution
A zoom lens configuration comprising a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with positive refractive power, where the first and second lens groups move along the optical axis during zooming, with specific refractive index and Abbe number conditions to optimize optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional zoom lens configuration is used, then the lens can perform telephotography, but the optical performance is not ideal
Solution Approach 1:
The zoom lens is divided into three distinct lens groups (first lens group with negative refractive power, second lens group with positive refractive power, and third lens group with positive refractive power) arranged in sequence from the object side. This segmentation allows each group to be optimized for specific functions while working together to achieve ideal optical performance across the zoom range.
Solution Approach 2:
Each lens group is assigned specific optical properties: the first lens group has negative refractive power for wide-angle coverage, the second lens group has positive refractive power for intermediate focal lengths, and the third lens group has positive refractive power for telephoto capabilities. This local optimization of optical properties enables the entire system to achieve ideal performance.
2Adaptability or versatility
If the lens is designed for wide-angle of view, then the angle of view is wide, but the aperture ratio and zoom ratio are limited
Solution Approach 1:
The lens groups are designed to move dynamically along the optical axis during zooming operations. The first and second lens groups move in coordination to maintain optimal spacing, enabling the lens to transition smoothly from wide-angle to telephoto configurations while maintaining large aperture ratio and correcting aberrations across all focal lengths.
3Adaptability or versatility
If the lens is designed for high zoom ratio, then the zoom ratio is high, but the optical performance deteriorates
Solution Approach 1:
The patent specifies precise parameter ranges for the lens groups, including refractive power relationships (e.g., the second lens group has positive refractive power while the first has negative refractive power) and movement characteristics. These parameter optimizations ensure that optical performance is maintained across the entire zoom range from wide-angle to telephoto.
4Reliability
If more lens groups are added to improve optical performance, then the optical performance improves, but the device complexity increases
Solution Approach 1:
Each of the three lens groups serves multiple functions: the first lens group contributes to wide-angle coverage and aberration correction, the second lens group enables intermediate focal lengths and maintains aperture ratio, and the third lens group provides telephoto capability. This multi-functionality allows the lens to achieve high optical performance with a relatively simple three-group configuration.
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 ideal optical performance with a wide-angle of view, large aperture, and high zoom ratio, effectively correcting various aberrations across different focal lengths.
Implementation Method 1
a first lens group having negative refractive power; a second lens group having positive refractive power; and a third lens group having positive refractive power
Data Source
AI summary
Provided is a zoom lens (ZL) including, in order from an object along an optical axis: a first lens group (G1) having negative refractive power; a second lens group (G2) having positive refractive power, and a third lens group (G3) having a positive refractive power. At least the first lens group (G1) and the second lens group (G2) are moved along the optical axis upon zooming from a wide-angle end state to a telephoto end state, so that the distance between the first lens group (G1) and the second lens group (G2) decreases, and the distance between the second lens group (G2) and the third lens group (G3) increases, the first lens (G2) includes one positive lens, and the second lens (G2) includes one negative lens.