Five-Group Zoom Lens Compact Design Wide Angle Aberration Correction
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Solution Overview
Problem
Conventional zoom lenses for digital cameras are not compact enough and do not provide a wide enough angle of view, with many having long total lengths and limited aberration correction.
Innovation Solution
A zoom lens configuration consisting of a first negative refractive power lens group, a second positive refractive power lens group, a third negative refractive power lens group, a fourth positive refractive power lens group, and a fifth positive refractive power lens group, where the first four groups move along the optical axis to adjust distances and the fifth group is fixed, satisfying specific focal length and Abbe number conditions to achieve a compact design with a wide angle of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional zoom lens configurations are used, then the lens structure is simple, but the total length becomes long and the angle of view is limited
Solution Approach 1:
The zoom lens is divided into five distinct lens groups (G1 through G5) with alternating negative and positive refractive powers. This segmentation allows each group to be optimized for specific functions: G1 and G3 control the wide-angle performance and compactness, while G2, G4, and G5 contribute to telephoto performance and aberration correction. The segmented structure enables achieving both compact total length and wide angle of view without excessive complexity.
2Device complexity
If conventional zoom lens configurations are used, then the lens structure is simple, but the angle of view is limited to approximately 100 degrees
Solution Approach 1:
The first lens group G1 with negative refractive power is specifically designed with particular focal length ratios (0.15 < |f1/f2| < 0.35 and 0.20 < |f1/f3| < 0.40) to optimize the wide-angle end performance. This local optimization of specific lens group parameters enables the overall system to achieve a full angle of view of approximately 110 degrees while maintaining a relatively simple five-group structure.
3Illumination intensity
If the lens is designed for wider angle of view, then the angle of view increases to approximately 110 degrees, but the total length increases
Solution Approach 1:
The patent merges the wide-angle and telephoto functionalities into a unified five-lens-group zoom lens system. By combining negative-power groups (G1, G3) for wide-angle control with positive-power groups (G2, G4, G5) for telephoto extension, the design achieves a zoom ratio of 2.3x or more with a full angle of view of approximately 110 degrees, all within a compact total length that does not excessively increase despite the wider angle of view.
4Length of moving object
If compact design is pursued, then the total length is reduced, but aberration correction becomes insufficient
Solution Approach 1:
The five lens groups are arranged in a nested sequence along the optical axis with alternating negative and positive refractive powers. This nested configuration allows multiple lens groups to be compactly positioned while each group contributes to correcting specific aberrations. The negative-power groups (G1, G3) correct field curvature and distortion, while the positive-power groups (G2, G4, G5) correct spherical aberration and chromatic aberration, achieving satisfactory aberration correction within a compact total length.
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 results in a compact zoom lens with a short total length and a full angle of view of approximately 110 degrees, effectively correcting various aberrations and enabling miniaturization while maintaining high image quality.
Implementation Method 1
a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a positive refractive power
Data Source
AI summary
A zoom lens substantially consists of a negative first lens group, a positive second lens group, a negative third lens group, a positive fourth lens group, and a positive fifth lens group in this order from the object side; whereinthe first lens group through the fourth lens group move along the optical axis while changing magnification from the wide angle end to the telephoto end so as to change the distances among one another such that the distance between the first lens group and the second lens group is reduced and the distance between the second lens group and the third lens group is increased;the fifth lens group is fixed with respect to an image surface while changing magnification; andconditional formulas (1) and (2) below are satisfied:0.15<|f1|/f2<1.00 (1)0.1<f4/f5<1.1 (2).