Five-Lens Imaging System for Compact Wide-Angle Aberration Control
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Solution Overview
Problem
Conventional imaging lenses face challenges in achieving a low-profile design with a wide field of view and high brightness while effectively correcting aberrations, particularly in the peripheral areas of the image.
Innovation Solution
The proposed imaging lens configuration consists of an aperture stop followed by a positive first lens, a negative meniscus second lens, a positive aspheric third lens, a positive double-sided aspheric fourth lens, and a negative double-sided aspheric fifth lens, with specific focal length and curvature radius relationships that optimize refractive power and aberration correction, ensuring a virtually telephoto type system with a biconvex first lens and biconcave fifth lens for improved telephoto capability and aberration control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the imaging lens is designed to be low-profile with total track length shorter than the diagonal length of the effective imaging plane, then the lens can be applied to compact mobile devices, but it becomes difficult to correct aberrations in the peripheral area of the image
Solution Approach 1:
The imaging lens is divided into five distinct constituent lenses (first through fifth lenses) with specific positive and negative refractive powers. This segmentation allows each lens to contribute differently to the overall optical performance, enabling aberration correction in the peripheral areas while maintaining a compact total track length that is shorter than the diagonal length of the effective imaging plane.
Solution Approach 2:
Each constituent lens is designed with specific local optical properties: the first lens has positive refractive power, the second lens has negative refractive power, the third lens has positive refractive power with at least one aspheric surface, the fourth lens has positive refractive power as a double-sided aspheric lens, and the fifth lens has negative refractive power as a double-sided aspheric lens. These localized optical characteristics enable effective aberration correction throughout the image plane while maintaining a low-profile design.
2Illumination intensity
If the imaging lens is designed to provide high brightness with an F-value of 2.5 or less, then the lens can capture more light for better image quality, but it becomes difficult to correct aberrations in the peripheral area of the image
Solution Approach 1:
The five-lens segmentation enables different portions of the optical system to handle different functions: some lenses contribute to achieving high brightness (F-value of 2.5 or less) while others specifically address aberration correction in the peripheral areas, resolving the contradiction between brightness and aberration correction.
Solution Approach 2:
The specific assignment of refractive powers and aspheric surfaces to different lenses creates local optical zones that collectively achieve both high brightness and proper aberration correction. The combination of positive and negative refractive powers in different lenses allows the system to maintain high light transmission while correcting peripheral aberrations.
3Area of stationary object
If the imaging lens is designed to provide a wide field of view of 70 degrees or more, then the lens can capture broader scenes, but it becomes difficult to correct aberrations in the peripheral area of the image
Solution Approach 1:
The five-lens segmented configuration allows different lenses to handle different angular ranges of the wide field of view. This segmentation enables the system to achieve a field of view of 70 degrees or more while maintaining aberration correction capability across the entire peripheral area through the coordinated action of individual lenses with specific refractive powers and aspheric surfaces.
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
This configuration results in a compact, low-cost imaging lens that provides a wide field of view of 70 degrees or more and high brightness with an F-value of 2.5 or less, effectively correcting various aberrations and maintaining high image quality throughout the image plane, suitable for compact mobile devices.
Implementation Method 1
an imaging lens which forms an image of an object on a solid-state image sensor
Implementation Method 2
a third lens with positive refractive power having at least one aspheric surface; a fourth lens with positive refractive power as a double-sided aspheric lens; and a fifth lens with negative refractive power as a double-sided aspheric lens
Data Source
AI summary
An imaging lens elements are arranged in order from an object side, an aperture stop, positive first lens having convex object-side and image-side surfaces, negative meniscus second lens having a concave image-side surface, positive third lens having at least one aspheric surface, positive double-sided aspheric fourth lens, and negative double-sided aspheric fifth lens having concave object-side and image-side surfaces with its image-side surface having a pole-change point off the axis. It satisfies conditional expressions below:0.5<f1/f<1.0 (1)10.0<f3/f (2)0.8<(r3+r4)/(r3−r4)<2.0 (3)wheref: focal length of the imaging lens overall optical systemf1: first lens focal lengthf3: third lens focal lengthr3: curvature radius of the second lens object-side surfacer4: curvature radius of the second lens image-side surface.