Zoom Lens Chromatic Aberration Correction via Solid Material Dispersion Control
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Solution Overview
Problem
Conventional zoom lenses face challenges in effectively correcting chromatic aberration across the entire zooming range, particularly at the wide-angle and telephoto ends, due to the limitations of using extraordinary partial dispersion materials and liquid materials, which can be complex to manufacture and have poor environmental resistance.
Innovation Solution
A zoom lens design comprising a first lens unit with a positive refractive power made of a solid material satisfying specific Abbe number and relative partial dispersion conditions, combined with a varying interval between lens units, effectively corrects chromatic aberration and maintains optical performance throughout the zooming range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an extraordinary partial dispersion material such as fluorite is used to correct chromatic aberration, then chromatic aberration can be corrected at one end (wide-angle or telephoto), but chromatic aberration deteriorates at the other end
Solution Approach 1:
The patent applies parameter changes by precisely controlling the Abbe number (νd) within 15.0-30.0 and relative partial dispersion (θgF) within 0.60-0.70 of the positive lens material, and positioning the lens at specific distances from the object (0.30-0.60 times the focal length). These parameter optimizations enable effective chromatic aberration correction across the entire zoom range, resolving the contradiction between correcting chromatic aberration at one end versus maintaining consistency at both ends.
2Manufacturing precision
If liquid material with high dispersion is used to correct chromatic aberration, then chromatic aberration can be easily corrected, but the structure becomes complex and environmental resistance deteriorates
Solution Approach 1:
The patent replaces liquid materials requiring complex sealing structures with solid lens materials that have appropriate dispersion characteristics. This substitution eliminates the need for sealing structures while maintaining chromatic aberration correction capability, thereby reducing device complexity and improving environmental resistance.
Solution Approach 2:
The patent uses solid lens materials with specifically controlled optical properties (Abbe number 15.0-30.0, relative partial dispersion 0.60-0.70) to achieve chromatic aberration correction. This approach using composite optical materials provides both correction effectiveness and structural simplicity, avoiding the complexity associated with liquid material sealing.
3Manufacturing precision
If liquid material is used for chromatic aberration correction, then correction is easy, but refractive index and dispersion vary with temperature making environmental resistance poor
Solution Approach 1:
The patent substitutes liquid materials with temperature-sensitive optical properties with solid lens materials that maintain stable refractive indices and dispersion characteristics across temperature variations. This substitution eliminates environmental sensitivity while preserving chromatic aberration correction capability.
Solution Approach 2:
The patent optimizes the material parameters (Abbe number 15.0-30.0, relative partial dispersion 0.60-0.70) to achieve temperature-stable chromatic aberration correction. By carefully selecting solid materials within these parameter ranges, the system maintains consistent optical performance across different environmental conditions.
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 excellent chromatic aberration correction and enhanced optical performance over the entire zooming range while minimizing the complexity of the optical system and maintaining environmental resistance.
Implementation Method 1
an optical element GIT having a positive refractive power and made of a solid material having an Abbe number (νd) and a relative partial dispersion (θgF)
Implementation Method 2
a first lens unit, a second lens unit, and an image-side lens unit arranged in order from an object side to an image side, wherein the first lens unit has a positive refractive power
Data Source
AI summary
At least one exemplary embodiment is directed to a zoom lens includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and an image-side lens unit in order from an object side to an image side wherein an interval between the first lens unit and the second lens unit varies during zooming, the first lens unit includes an optical element having a positive refractive power and made of a solid material having an Abbe number (νd) and a relative partial dispersion (ΘgF) satisfying the following conditions:0.755ΘgF−(−1.665×10−7·νd3+5.213×10−5·νd2−5.656×10−3·νd)<1.011and1.6<(ft/f1)2<5.6,wherein f1is the focal length of the first lens unit and ft is the focal length of the zoom lens at a telephoto end.