Zoom Lens High Magnification Compact Design
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Solution Overview
Problem
Conventional compact zoom lenses with high variable magnification ratios are limited to less than 10×, failing to meet the demand for lenses with ratios exceeding 12× while maintaining compactness and high performance.
Innovation Solution
A zoom lens configuration comprising five lens groups with specific refractive powers, where the distance between certain groups is adjusted during zooming to satisfy certain focal length ratios, allowing for a high variable magnification ratio exceeding 12× while maintaining compactness and high performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a zoom lens with high variable magnification ratio is designed, then the magnification ratio exceeds 12×, but the lens size and complexity increase
Solution Approach 1:
The zoom lens is divided into five lens groups with specific refractive powers (positive, negative, positive, positive, negative) arranged in sequence. Each lens group is independently movable relative to the image formation position, allowing precise control of the zoom ratio while maintaining a compact overall structure. This segmentation enables high variable magnification ratio (over 12×) without excessive increase in lens size.
2Adaptability or versatility
If the distance between lens groups is adjusted to achieve high zoom ratio, then the variable magnification ratio exceeds 12×, but the lens structure becomes more complex
Solution Approach 1:
The patent implements a dynamic lens structure where all five lens groups can move relative to the image formation position during zooming. Specifically, the distance between the first and second lens groups is consistently increased, the distance between the second and third lens groups is consistently decreased, and the distance between the third and fourth lens groups is consistently decreased. This coordinated dynamic movement enables high variable magnification ratio (over 12×) while maintaining manageable structural complexity through systematic group positioning.
3Volume of moving object
If the lens is made compact for portability, then the lens size is reduced, but the variable magnification ratio is limited to less than 10×
Solution Approach 1:
The patent changes the critical parameter of focal length ratio (fw/f1) to satisfy the condition 0.10 < fw/f1 < 0.15, where fw is the focal length of the entire lens system at the wide angle end and f1 is the focal length of the first lens group. This parameter optimization enables the lens to achieve a high variable magnification ratio (over 12×) while maintaining a compact size, effectively resolving the contradiction between compactness and zoom capability.
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 a zoom lens with a high variable magnification ratio exceeding 12×, achieving a large angle of view and compact design, while maintaining optical performance across the zoom range.
Implementation Method 1
a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having positive refractive power; and a fifth lens group having negative refractive power
Data Source
AI summary
A zoom lens substantially consists of, in order from the object side, a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a negative fifth lens group. When varying magnification from the wide angle end to the telephoto end, a distance between the first lens group and the second lens group is always increased, a distance between the second lens group and the third lens group is always decreased, a distance between the third lens group and the fourth lens group is always decreased, and a distance between the fourth lens group and the fifth lens group is changed, while all of the lens groups are moved with respect to an image formation position. Formulas (Ca): −5.00≦1−(β5T)2<−2.5 and (D): 0.10<fw/f1<0.25 are satisfied.