Zoom Lens with Moving Lens Groups for Compact High Zoom Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional zoom lenses face challenges in achieving a balance between compact size, high zoom ratio, and good image quality while maintaining low costs, particularly due to the limitations of plastic lenses in terms of moisture and light absorption.
Innovation Solution
A zoom lens design comprising four lens groups with specific refractive powers, where the second and fourth lens groups are moved along the optical axis for zooming, incorporating aspheric or free-form lenses made of plastic or glass, and including a reflector to enhance compactness and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If plastic lenses are employed to reduce cost, then manufacturing cost is reduced, but image quality deteriorates due to moisture and light absorption
Solution Approach 1:
The patent employs a composite lens structure where plastic lenses are combined with anti-reflective and moisture-resistant coating layers. This composite approach allows the use of cost-effective plastic material while the protective coatings mitigate the drawbacks of moisture and light absorption, thereby maintaining image quality without sacrificing cost advantages.
Solution Approach 2:
The patent uses plastic lenses as a cost-effective alternative to traditional glass lenses. While plastic lenses may have shorter lifespan and are more susceptible to environmental factors, the design incorporates protective measures and optimized optical paths to compensate for these limitations, achieving acceptable image quality at lower manufacturing costs.
2Adaptability or versatility
If the number of lens groups is increased to achieve high zoom ratio, then zoom ratio is improved, but device complexity increases
Solution Approach 1:
The zoom lens is divided into four distinct lens groups with specific functions: the first group for wide-angle focus, the second for telephoto focus, the third for image quality correction, and the fourth for additional zoom capability. This segmentation allows each group to be optimized for its specific function, achieving high zoom ratio while managing complexity through functional specialization.
Solution Approach 2:
The patent implements a dynamic zoom mechanism where the second and fourth lens groups move along the optical axis during zooming operations. This dynamic configuration allows the lens to achieve high zoom ratios by changing the relative positions of lens groups, rather than requiring a fixed complex arrangement of many lens elements.
3Adaptability or versatility
If lens groups are moved along optical axis for zooming, then zoom ratio is improved, but spherical aberration increases
Solution Approach 1:
The patent applies local quality optimization by designing each lens group with specific aberration-correcting features. The third lens group, in particular, is configured to correct spherical aberration that arises during zooming operations. By localizing the correction function to specific lens groups rather than requiring all groups to be perfectly corrected, the system achieves high zoom ratio while controlling spherical aberration.
Solution Approach 2:
The third lens group acts as an intermediary between the first two groups (which provide zoom capability through movement) and the image sensor. This intermediary group is specifically designed to correct spherical aberration introduced by the moving lens groups, mediating between the zoom function and image quality requirements.
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 a compact size, high zoom ratio, and improved image quality while reducing costs, with optimized spherical aberration, astigmatism, and distortion performance across the wide-angle and telephoto ends.
Implementation Method 1
a first lens group (G1) having positive refractive power
Implementation Method 2
a second lens group (G2) having negative refractive power
Implementation Method 3
a third lens group (G3) having positive refractive power
Implementation Method 4
a fourth lens group (G4) having positive refractive power
Data Source
AI summary
An embodiment of this invention provides a zoom lens that includes, in order from an object side to an image-forming side, a first lens group having positive refraction power; a second lens group having negative refraction power; a third lens group having positive refraction power; and a fourth lens group having positive refraction power; wherein the second lens group and the fourth lens group move along an optical axis for zooming between a wide-angle end and a telephoto end.