Four-Element Aspheric Lens Assembly for Infrared Aberration Control
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Solution Overview
Problem
Conventional compact optical lens systems fail to meet the demands for high image quality, wide angle, and infrared motion capturing due to limitations in their design, particularly in reducing aberrations and accommodating higher megapixels and infrared wavelengths.
Innovation Solution
A compact image capturing lens assembly comprising four lens elements with specific refractive powers and surface curvatures, including aspheric surfaces, arranged to provide retrofocus functionality, balanced refractive power distribution, and corrected aberrations, allowing for wide-angle and high-definition imaging suitable for infrared applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional three-element lens structure is used, then the device complexity is reduced, but the image quality and aberration correction are insufficient
Solution Approach 1:
The lens system is divided into four distinct lens elements with specific refractive powers and surface curvatures. Each element is optimized for specific aberration correction: the first element (negative power) corrects spherical aberration, the second element (positive power) controls coma, the third element (positive power) corrects astigmatism, and the fourth element (positive power with aspheric surfaces) corrects field curvature and distortion. This segmentation allows comprehensive aberration correction while maintaining a compact form factor suitable for mobile devices.
2Adaptability or versatility
If the lens assembly is designed for wide angle functionality, then the field of view is expanded, but the aberration control becomes more difficult
Solution Approach 1:
The fourth lens element incorporates aspheric surfaces on both its object-side and image-side surfaces. These aspheric surfaces are defined by specific curvature radius relationships (0.3<f4<0.6 and 0.5<(R7+R8)/(R7-R8)<1.5) that enable effective correction of wide-angle aberrations including field curvature and distortion. The aspheric profiles allow the lens to maintain high image quality across the entire wide field of view by varying the surface curvature continuously rather than using fixed spherical surfaces.
3Reliability
If the lens elements are optimized for infrared wavelengths (780-950 nm), then the infrared sensitivity is improved, but the design complexity increases
Solution Approach 1:
The lens system is optimized for infrared wavelengths by selecting specific refractive index ranges for each lens element (1.45<n1<1.55, 1.50<n2<1.60, 1.52<n3<1.62, 1.50<n4<1.58) and configuring specific curvature radius relationships. The fourth element's aspheric surfaces are designed with curvature radii satisfying 0.3<f4<0.6 and 0.5<(R7+R8)/(R7-R8)<1.5, which are specifically tailored for infrared performance. These parameter optimizations enable the lens to achieve high transmission and focusing accuracy in the 780-950 nm infrared range while maintaining a compact structure.
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 lens assembly achieves improved image quality, reduced aberrations, and enhanced sensitivity for infrared imaging, meeting the demands of compact mobile electronic devices with wide-angle and high-definition capabilities.
Implementation Method 1
a first lens element, a second lens element, a third lens element and a fourth lens element... The first lens element with negative refractive power... The second lens element with positive refractive power... The third lens element with positive refractive power... The fourth lens element with positive refractive power
Implementation Method 2
the object-side surface and the image-side surface of the fourth lens element are aspheric
Data Source
AI summary
An image capturing lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element. The first lens element with negative refractive power has an object-side surface being convex and an image-side surface being concave. The second lens element with positive refractive power has an object-side surface and an image-side surface being both convex. The third lens element with positive refractive power has an object-side surface being concave and an image-side surface being convex. The fourth lens element with positive refractive power has an object-side surface being convex, and an image-side surface being concave at a paraxial region and being convex at a peripheral region, wherein the surfaces of the fourth lens element are aspheric.