Compact Imaging Lens with Aspheric Surfaces for Aberration Control
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Solution Overview
Problem
Conventional imaging lenses for compact devices fail to achieve a balance between low-profile design, wide field of view, and high optical performance, often struggling with aberration correction and brightness, especially in peripheral areas.
Innovation Solution
The imaging lens configuration includes a first lens with strong positive refractive power, a second lens correcting spherical and chromatic aberrations, a third lens as a double-sided aspheric lens for axial chromatic and high-order aberration correction, a fourth meniscus lens for chromatic and field curvature correction, a fifth double-sided aspheric lens for field curvature and distortion control, and a sixth lens securing back focus while maintaining low-profile design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a conventional six-lens structure is used to achieve low-profileness, then total track length is reduced, but field of view and optical performance are insufficient
Solution Approach 1:
The patent applies aspheric surfaces to multiple lenses (first, third, fourth, and sixth lenses) to correct spherical aberration and enable wider field of view in a compact configuration. The aspheric coefficients are specifically optimized to maintain high optical performance while reducing total track length below 5.5mm and achieving field of view of 75 degrees or more.
Solution Approach 2:
The patent optimizes specific parameter ranges including focal lengths of individual lenses (f1, f2, f3, f4, f6), their spacing (d1, d2, d3, d4, d5), and refractive indices (Nd1, Nd2, Nd3, Nd4, Nd6) to achieve the contradiction resolution. The conditional expressions define precise parameter ranges that enable compact design with wide field of view and high optical performance.
2Adaptability or versatility
If lens structure is optimized for low-profileness and wide field of view, then total track length and field of view are improved, but aberration correction in peripheral area deteriorates
Solution Approach 1:
Aspheric surfaces are applied to five out of six lenses with specifically optimized aspheric coefficients to correct spherical aberration, coma, and other off-axis aberrations. This enables wide field of view (75 degrees or more) while maintaining high image quality across the entire image plane including peripheral areas.
Solution Approach 2:
Different lenses have different aspheric surface configurations tailored to their specific functions: the first lens corrects spherical aberration, the third lens addresses coma and astigmatism, the fourth lens corrects field curvature, and the sixth lens refines overall aberration correction. This localized optimization ensures high optical performance throughout the image.
3Illumination intensity
If F-value is reduced for higher brightness, then illumination intensity is improved, but optical system complexity increases
Solution Approach 1:
Aspheric surfaces on multiple lenses enable the optical system to achieve F-value of 2.3 or less (higher brightness) while maintaining compact size and controlling aberrations. The aspheric profiles are specifically designed to manage light rays at wide field of view angles, enabling low F-value without proportionally increasing system complexity.
Solution Approach 2:
Each lens in the six-lens system performs multiple functions: correcting various types of aberrations (spherical, chromatic, coma, astigmatism, field curvature), controlling light paths, and contributing to the overall low F-value. This multi-functionality reduces the need for additional corrective elements that would increase complexity.
4Length of stationary object
If total track length is reduced for compact design, then device size is minimized, but optical performance and aberration correction deteriorate
Solution Approach 1:
The aspheric surfaces are the key enabling technology that allows total track length of 5.5mm or less while maintaining high optical performance. The aspheric coefficients are optimized to correct all major aberration types in the compact configuration, ensuring diffraction-limited performance across the wide field of view.
Solution Approach 2:
The patent defines specific parameter ranges for focal lengths, lens spacings, and refractive indices that enable compact design with high optical performance. The conditional expressions establish the optimal parameter space where compact size and high image quality coexist, with total track length below 5.5mm and field of view of 75 degrees or more.
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 enables a compact imaging lens with a total track length under 5.5 mm, F-number of 2.3 or less, and a field of view of 75 degrees or more, effectively correcting various aberrations and providing high-resolution images.
Implementation Method 1
a first lens having positive refractive power and a convex surface facing an object side near an optical axis
Implementation Method 2
a second lens having negative refractive power and a concave surface facing an image side near an optical axis
Implementation Method 3
a third lens having positive refractive power and a concave surface facing the image side near an optical axis as a double-sided aspheric lens
Data Source
AI summary
Compact imaging lens which maintains low-profileness, wide field of view, and properly corrects various aberrations. Imaging lens includes first lens having positive refractive power and convex surface facing object side near an optical axis, second lens having negative refractive power and concave surface facing image side near optical axis, third lens having positive refractive power and concave surface facing image side near optical axis as double-sided aspheric lens, fourth lens having meniscus shape with positive refractive power and concave surface facing object side near optical axis, fifth lens as double-sided aspheric lens, and sixth lens having negative refractive power and concave surface facing image side near optical axis as double-sided aspheric lens, and conditional expression is satisfied: (1) 0.6<Σd/f<1.0, where Σd denotes distance along optical axis from object-side surface of first lens to image-side surface of sixth lens, and f denotes focal length of overall optical system of imaging lens.