Zoom Optical System Aberration Control via Five-Group Lens Segmentation
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Solution Overview
Problem
Conventional zoom optical systems face challenges in increasing zooming and angle of view without a corresponding increase in size, while maintaining preferable optical performance.
Innovation Solution
A zoom optical system comprising a configuration of lens groups with specific refractive powers, including a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, a fourth lens group with negative refractive power, and a fifth lens group with positive and negative lenses, where the lens groups are moved along the optical axis to change distances between them, satisfying certain focal length and F-number ratios to achieve high optical performance and reduced aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional zoom optical systems increase zooming and angle of view, then the field of view and magnification range are improved, but the size of the lens system increases
Solution Approach 1:
The zoom optical system is divided into five distinct lens groups (G1-G5) with alternating positive and negative refractive powers. Each group can move independently along the optical axis during zooming, allowing precise control of focal length changes without requiring proportional increases in overall system size. This segmentation enables compact packaging of the optical elements while achieving high zooming capability.
Solution Approach 2:
The lens groups are arranged in a nested configuration where smaller lens groups are positioned within or adjacent to larger ones. The fifth lens group (G5) with positive refractive power is positioned to overlap with the fourth lens group (G4) with negative refractive power, creating a compact nested structure that reduces the overall length and volume of the lens system while maintaining the required optical path for high zooming.
2Adaptability or versatility
If conventional zoom optical systems increase zooming ratio, then the magnification capability is improved, but the optical performance deteriorates due to increased aberrations
Solution Approach 1:
Each lens group is designed with specific local optical properties: G1 and G3 have positive refractive power for convergence, while G2 and G4 have negative refractive power for divergence. The fifth lens group G5 with positive refractive power is specifically designed to correct aberrations introduced by the negative groups. This localized optimization of refractive power distribution allows high zooming ratio while maintaining excellent optical performance across the entire zoom range.
Solution Approach 2:
The negative refractive power lens groups (G2 and G4) intentionally introduce certain aberrations that are then corrected by the positive refractive power groups (G1, G3, and G5). This approach converts the harmful effect of aberrations from negative groups into a design feature where the positive groups are optimized to specifically counterbalance these aberrations, enabling high zooming ratio with maintained optical quality.
3Reliability
If conventional zoom optical systems use more lens groups to improve performance, then the optical quality is improved, but the device complexity increases
Solution Approach 1:
The five lens groups are combined into a single integrated zoom optical system where the groups work cooperatively. The aperture stop is positioned within the third lens group G3, merging the aperture function with the lens group structure. This integration reduces the number of separate components and simplifies the overall device complexity while maintaining high optical performance through the coordinated action of all five lens groups.
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
This configuration allows for a higher zooming rate, reduced aberrations, and a smaller lens barrel size, while maintaining excellent imaging performance and correcting spherical and coma aberrations, thereby addressing the limitations of conventional systems.
Implementation Method 1
a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power that are disposed in order from an object
Data Source
AI summary
A zoom optical system (ZL) comprises a first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having negative refractive power, and a fifth lens group (G5) having positive refractive power that are disposed in order from an object. Upon zooming from a wide angle end state to a telephoto end state, the lens groups are moved along an optical axis to change distances between the lens groups. The fifth lens group (G5) comprises at least one positive lens and at least one negative lens. Certain conditional expressions are satisfied.