Four-Element Imaging Lens for Compact Optical Systems
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Solution Overview
Problem
Conventional imaging lenses for portable electronic devices face challenges in reducing overall length without compromising optical performance, often resulting in compromised imaging quality due to wide gaps between lens elements.
Innovation Solution
An imaging lens design featuring four lens elements with specific refractive powers and surface geometries, including convex and concave portions, optimized to maintain optical performance while reducing system length, comprising a first positive refractive power lens with a convex object-side surface, a second negative refractive power lens with a convex image-side surface, a third positive refractive power lens with a concave object-side surface, and a fourth negative refractive power lens with concave and convex portions, all arranged to minimize system length while controlling aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the overall length of the imaging lens is reduced, then the miniaturization of portable electronic devices is achieved, but the optical performance and imaging quality are compromised
Solution Approach 1:
The patent applies parameter changes by optimizing the refractive powers, curvatures, and spacing of the four lens elements. Specific parameters including the focal lengths (f1, f2, f3, f4), curvature radii (r1, r2, ..., r12), and axial distances (d1, d2, d3, d4) are carefully selected to achieve compact dimensions while maintaining optical performance. The fourth lens element's unique dual-convex-concave surface configuration represents a parameter change that enables shorter overall length without sacrificing imaging quality
Solution Approach 2:
The imaging lens is segmented into four distinct lens elements with specific refractive powers and surface geometries. This segmentation allows each element to perform specific optical functions: the first element (positive power) for initial convergence, the second element (negative power) for divergence and aberration correction, the third element (positive power) for re-convergence, and the fourth element (negative power with unique surfaces) for final correction and compactness. This division enables optimized performance in a compact form
2Reliability
If wide gaps are maintained between lens elements, then optical performance is preserved, but the system length increases
Solution Approach 1:
The patent changes the spacing parameters (d1, d2, d3, d4) between lens elements to achieve optimal compact configuration. The gaps are minimized while maintaining optical performance through careful selection of these parameters, allowing the system to achieve shorter length compared to conventional designs that require larger gaps for aberration correction
Solution Approach 2:
The patent employs a composite optical system combining four lens elements with different refractive powers and surface geometries. This composite structure enables the system to achieve both compact dimensions and high optical performance by leveraging the complementary properties of each lens element, particularly the fourth element's unique dual-convex-concave 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 design achieves reduced system length below 3 mm while maintaining good optical performance, minimizing spherical aberration, chromatic aberration, and distortion, thus supporting the miniaturization of portable electronic devices with improved imaging quality.
Implementation Method 1
The first lens element has a positive refractive power, and the object-side surface thereof is a convex surface
Implementation Method 2
The second lens element has a negative refractive power, and the image-side surface thereof has a convex portion in a vicinity of an optical axis of the imaging lens
Implementation Method 3
The object-side surface of the third lens element has a concave portion in a vicinity of the optical axis of the imaging lens
Implementation Method 4
The image-side surface of the fourth lens element has a concave portion in a vicinity of an optical axis of the imaging lens, and a convex portion in a vicinity of a periphery of the fourth lens element
Data Source
AI summary
An imaging lens includes a first lens element, a second lens element, a third lens element, and a fourth lens element arranged from an object side to an image side in the given order. The image-side surface of the first lens element comprises a convex portion in a vicinity of a periphery of the first lens element. The imaging lens has a system length less than 3.0 mm. The imaging lens does not have any lens element with refractive power other than the first, second, third, and fourth lens elements.