Compact Zoom Lens Aberration Correction Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing zoom lenses face challenges in achieving both high magnification and miniaturization while maintaining optical performance, often requiring a trade-off between miniaturization and cost or sacrificing one for the other due to difficulties in correcting aberrations and managing lens group movements during zooming.

Innovation Solution

A compact zoom lens design comprising a first negative lens group, a second positive lens group with a stop, and a third positive lens group, where the intervals between these groups adjust during zooming to satisfy specific focal length and refractive power expressions, incorporating aspherical and spherical lenses to optimize refractive indices and aberration correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the number of lenses in the second lens group is increased to 4 or more, then chromatic aberration can be easily corrected, but zoom magnification cannot be attained and the lens becomes ultra-compact

Engineering Contradiction:

Improvechromatic aberration correctionVSAvoidzoom magnification capability

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the parameter of lens count in the second lens group from 4 or more to 2 or 3 lenses, while simultaneously adjusting the refractive indices and focal lengths of individual lenses to achieve both chromatic aberration correction and zoom magnification capability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent assigns specific refractive index ranges to individual lenses in the second lens group (e.g., NL21: 1.8<nd<2.3, NL22: 1.5<nf<1.7) to optimize local optical properties for aberration correction while maintaining overall zoom functionality

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If a zoom lens is designed to form high magnification of 5× or greater, then zoom magnification is achieved, but miniaturization is difficult due to large change in distance between second and third lens groups

Engineering Contradiction:

Improvezoom magnificationVSAvoidlens barrel size

Core Design Contradiction:

Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The patent sets the zoom magnification ratio ft/fw within 4.0-6.0 (optimizing for high magnification without excessive size) and controls the distance change ratio (D2t-D2w)/fw within 2.5-4.0 to balance magnification achievement with compact lens barrel dimensions

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent defines dynamic movement ranges for lens groups during zooming, with the second lens group moving a distance of 0.1-0.4 times the overall focal length at wide angle position, optimizing the dynamic behavior to achieve high magnification while minimizing lens barrel size

Inventive Principle:

Principle #15Dynamics

3Length of moving object

If miniaturization is achieved in zoom lens design, then compact size is obtained, but optical performance and high zoom magnification are sacrificed

Engineering Contradiction:

Improvelens barrel sizeVSAvoidoptical performance

Core Design Contradiction:

Length of moving objectVSManufacturing precision

Solution Approach 1:

The patent optimizes multiple parameters simultaneously including lens count (2-3 lenses in second group), refractive indices (specific ranges for each lens), and focal length ratios (ft/fw: 4.0-6.0) to achieve compact size while maintaining high optical performance including chromatic aberration correction

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses lenses with different refractive index characteristics (high refractive index lenses with nd>1.8 and low refractive index lenses with nd<1.7) combined in the second lens group to achieve superior optical performance in a compact configuration

Inventive Principle:

Principle #40Composite materials

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 design achieves high magnification of 4.5× or greater while maintaining a compact size and reducing manufacturing costs, effectively correcting chromatic and spherical aberrations, and facilitating the formation of a small lens barrel.

Implementation Method 1

a lens disposed second from the object side from among the lenses of the first lens group may be an aspherical lens of which at least one surface is aspherical

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

effectively correcting chromatic and spherical aberrations

Methodology Applied

Scientific EffectSpherical aberration correction:

Implementation Method 3

The second lens group may include a doublet lens

Methodology Applied

Scientific EffectChromatic aberration correction:

Implementation Method 4

A difference between the Abbe's numbers of the two lenses of the first lens group may be 20 or greater

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS8547646B2Compact zoom lens

Publication Date: 2013.10.01 SAMSUNG ELECTRONICS CO LTD

AI summary

A zoom lens includes, in a sequence from an object side to an image side, a first lens group having a negative refractive power and comprising two lenses; a second lens group having a positive refractive power; a stop disposed on the image side of the second lens group; and a third lens group having a positive refractive power, wherein: during zooming from a wide angle position to a telephoto position, an interval between the first lens group and the second lens group decreases, and an interval between the second lens group and the third lens group increases.