Multi-Group Zoom Lens Layout for High Ratio and Low Weight
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Solution Overview
Problem
There is a demand for a zoom lens with a small size and light weight while achieving a high zoom ratio, which existing technologies have not adequately addressed.
Innovation Solution
A zoom lens configuration comprising a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group with multiple lens groups, where the aperture stop is positioned closer to the image side than the lens surface of the second lens group, and specific conditional expressions are satisfied to optimize lens spacings and refractive indices, including concave and convex surfaces to achieve a high zoom ratio and reduced size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a zoom lens is designed to achieve a high zoom ratio, then the zoom ratio is improved, but the size and weight of the lens increase
Solution Approach 1:
The lens system is divided into multiple lens groups (first lens group with positive refractive power, second lens group with negative refractive power, and subsequent groups) that can move independently relative to each other during zooming. This segmentation allows the lens to achieve high zoom ratios by changing the spacing between groups rather than requiring a monolithic large lens structure, thereby reducing overall weight.
Solution Approach 2:
The patent employs dynamic adjustment of spacing between lens groups during zooming operations. The first lens group, second lens group, and subsequent groups are positioned at variable distances from each other to achieve different focal lengths. This dynamic configuration enables high zoom ratios while maintaining a compact form factor and reduced weight compared to static lens designs.
2Adaptability or versatility
If a zoom lens is designed to achieve a high zoom ratio, then the zoom ratio is improved, but the size of the lens increases
Solution Approach 1:
The lens groups are arranged in a nested configuration where the first lens group, second lens group, and subsequent groups are positioned within a compact structure. During zooming, the groups move relative to each other in a nested manner, allowing the lens to achieve high zoom ratios without significantly increasing the overall length. The concave lens surfaces and specific spacing relationships enable this compact nested arrangement.
Solution Approach 2:
The patent utilizes changes in the spatial arrangement of lens groups in multiple dimensions during zooming. By adjusting the spacing between groups in the optical axis direction and utilizing concave and convex surface geometries, the lens achieves high zoom ratios without a linear increase in length. The dimensional flexibility of the group configuration allows compact packaging while maintaining high adaptability.
3Adaptability or versatility
If lens groups are moved to change focal length during zooming, then the zoom ratio is improved, but the complexity of the lens mechanism increases
Solution Approach 1:
The lens mechanism is segmented into distinct lens groups (first lens group, second lens group, subsequent groups) that can be independently controlled. This segmentation simplifies the overall mechanism by allowing each group to be moved or positioned separately, reducing the complexity compared to a single complex moving element. The modular group structure enables easier control and manufacturing.
Solution Approach 2:
The patent achieves zooming by changing the spacing parameter between lens groups rather than requiring complex mechanical transformations. By adjusting the distance between the first lens group, second lens group, and subsequent groups along the optical axis, the focal length is changed in a relatively simple manner. This parameter-based approach reduces mechanical complexity compared to multi-degree-of-freedom mechanisms.
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 zoom ratio and reduced size and weight, while effectively correcting various aberrations and maintaining optical performance across zooming and focusing.
Implementation Method 1
a first lens group G1 that has a positive refractive power, a second lens group G2 that has a negative refractive power
Implementation Method 2
A lens group closest to the image side in the subsequent group includes at least one negative lens of which an object side lens surface is a concave surface being in contact with air
Data Source
AI summary
A zoom lens consisting of, in order from an object side to an image side: a first lens group that has a positive refractive power; a second lens group that has a negative refractive power; and a subsequent group that has a plurality of lens groups, wherein: the zoom lens includes an aperture stop at a position closer to the image side than a lens surface closest to the image side in the second lens group, a lens group closest to the image side in the subsequent group includes at least one negative lens of which an object side lens surface is a concave surface being in contact with air, during zooming, a spacing between the first lens group and the second lens group changes, a spacing between the second lens group and the subsequent group changes, and spacings between all adjacent lens groups in the subsequent group change.