Four-Element Lens Assembly with Aspheric Inflection Points
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional compact image capturing lens assemblies for portable electronic devices fail to produce high-quality images due to limitations in refractive power distribution, aberration correction, and manufacturing complexity, particularly with three-element and four-element lens structures.
Innovation Solution
A compact image capturing lens assembly comprising a four-element lens structure with specific refractive power distributions and aspheric surfaces, including a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power, and a fourth lens element with negative refractive power, optimized to reduce total track length and correct aberrations, while allowing for easier manufacturing and improved image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a three-element lens structure is used, then the lens assembly is compact, but the image quality is poor
Solution Approach 1:
The lens assembly is divided into four distinct lens elements instead of three, with each element having specific refractive power and surface curvature characteristics. This segmentation allows for better distribution of optical functions and aberration correction while maintaining a compact form factor suitable for portable electronic devices.
Solution Approach 2:
The patent employs asymmetric surface designs including convex and concave surfaces with different curvature radii for each lens element. The fourth lens element specifically features a convex object-side surface and a concave image-side surface with inflection points, creating asymmetric optical paths that improve image quality without significantly increasing overall assembly size.
2Manufacturing precision
If a four-element lens structure with glass spherical lenses is used, then chromatic aberration is eliminated, but the total optical track length increases and manufacturing becomes difficult
Solution Approach 1:
The patent utilizes both spherical and aspherical lens surfaces with carefully controlled curvature radii. The fourth lens element incorporates inflection points on its surfaces to optimize light ray convergence while maintaining a compact optical track length. This curved surface design enables effective aberration correction without requiring excessive optical path length.
Solution Approach 2:
The patent specifies precise parameter relationships including curvature radius ratios (0.3<R3/R4<1.5), thickness ratios (0.2<CT1+CT2+CT4/CT3<1.0), and axial distance ratios ((T23+T34)/T12<0.5) to optimize the four-element lens structure. These parameter optimizations enable effective aberration correction while controlling the total optical track length for compact device integration.
3Manufacturing precision
If glass spherical lenses are attached to form a doublet, then chromatic aberration is corrected, but the manufacturing process becomes difficult
Solution Approach 1:
The lens assembly is segmented into four separate lens elements that can be independently manufactured and then precisely positioned relative to each other. This segmentation approach simplifies the manufacturing process compared to creating complex glass doublets, as each element can be produced using standard lens fabrication techniques and then assembled with controlled axial distances.
Solution Approach 2:
The patent defines specific parameter ranges for axial distances (T12, T23, T34) and central thicknesses (CT1, CT2, CT3, CT4) that optimize both optical performance and manufacturability. These parameter specifications enable straightforward manufacturing and assembly processes while maintaining effective chromatic aberration correction through the four-element configuration.
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 proposed lens assembly achieves improved image quality by effectively distributing refractive power, correcting aberrations, and reducing the total track length, while simplifying the manufacturing process and maintaining a compact size.
Implementation Method 1
The fourth lens element with negative refractive power has a convex object-side surface and a concave image-side surface. The object-side surface and the image-side surface of the fourth lens element are aspheric, and the fourth lens element has at least one inflection point formed on at least one of the object-side surface and the image-side surface thereof.
Data Source
AI summary
An image capturing lens assembly comprises, in order from an object side to an image side, a first lens element with positive refractive power having a convex object-side surface, a second lens element with refractive power, a third lens element with positive refractive power having a convex image-side surface, and a fourth lens element with refractive power having a convex object-side surface and a concave image-side surface. The object-side surface and the image-side surface of the fourth lens element are aspheric and have at least one inflection point.