Three-Group Zoom Lens for Portable Devices
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Solution Overview
Problem
Existing portable electronic devices face challenges in integrating a zoom lens with a higher zoom ratio than f35=26 mm due to size constraints, and experience image distortion when switching between lens elements with different focal lengths.
Innovation Solution
A zoom lens design comprising a first lens group, a second lens group with positive refracting power, and a third lens group with negative refracting power, arranged along the optical axis to achieve a wide-angle and telephoto state, while satisfying specific relationships for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a telephoto lens with higher zoom ratio is installed in portable electronic products, then the zoom ratio is improved, but the lens size and thickness increase
Solution Approach 1:
The patent employs a dynamic lens structure where the second and third lens groups can move along the optical axis to adjust the focal length. By controlling the movement of these lens groups, the lens achieves variable zoom ratios (wide-angle to telephoto states) while maintaining a compact form factor suitable for portable electronic devices
Solution Approach 2:
The patent changes the refractive index parameters and curvature radii of the lens elements to optimize the zoom ratio within a compact size. Specifically, the second lens group has positive refracting power with specific curvature radius ranges, and the third lens group has negative refracting power with optimized parameters to achieve high zoom ratio without increasing overall lens dimensions
2Adaptability or versatility
If lens elements with different focal lengths are switched to achieve zoom, then the zoom ratio is improved, but image distortion increases
Solution Approach 1:
The patent applies different refractive powers and curvature characteristics to different lens groups. The second lens group has positive refracting power with specific curvature radius ranges, while the third lens group has negative refracting power with optimized parameters. This local differentiation of optical properties enables the lens to maintain image quality and minimize distortion across different focal lengths
Solution Approach 2:
The third lens group with negative refracting power acts as an intermediary element that compensates for the distortion introduced by the second lens group with positive refracting power. This intermediary lens group helps maintain image quality and reduce distortion when switching between different focal lengths
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 proposed zoom lens design allows for a higher zoom ratio within a compact form factor, minimizing image distortion and improving image processing efficiency, making it suitable for installation in portable electronic devices.
Implementation Method 1
the second lens group has positive refracting power, and there are only three lens groups of the zoom lens... the third lens group has negative refracting power
Data Source
AI summary
A zoom lens sequentially includes a first lens group, a second lens group and a third lens group along an optical axis from an object side to an image side. The zoom lens at least has a wide-angle state and a telephoto state, the second lens group has positive refracting power, and the zoom lens has only the above three lens groups and satisfies the following relationships: TTL*(Fnow+Fnot)/fw≤20.000, (ft+fw)/ImgH≥9.000 and ft/fw≥1.600. TTL is a system length of the zoom lens, Fnow is an f-number of the zoom lens in the wide-angle state, Fnot is an f-number of the zoom lens in the telephoto state, fw is an effective focal length of the zoom lens in the wide-angle state, ft is an effective focal length of the zoom lens in the telephoto state, and ImgH is a maximum image height of the zoom lens.