Six-Lens Optical Assembly with Negative First Element for Wide Field of View
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lens assemblies with six lenses fail to meet the requirements of miniaturization, wide field of view, and high resolution, necessitating a new structural design to enhance optical performance.
Innovation Solution
A lens assembly comprising specific configurations of lenses with varying refractive powers and curvatures, including a meniscus lens with negative refractive power, biconcave and biconvex lenses, and a meniscus lens with positive refractive power, arranged to optimize focal length, field of view, and resolution, while maintaining a shortened total lens length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional six-lens assembly is used, then the structure is relatively simple, but the field of view is limited and resolution is insufficient
Solution Approach 1:
The lens assembly is divided into six distinct lens elements with specific refractive powers and curvature configurations. Each lens element (first through sixth lenses) has optimized surface radii and thicknesses to collectively achieve wide field of view while maintaining manageable structural complexity through systematic segmentation of optical functions
Solution Approach 2:
Different regions of the lens assembly have specialized optical properties. The first lens has negative refractive power with specific convex/concave surface configurations, while the fifth lens has positive refractive power. Each lens element is positioned and shaped to correct specific aberrations in its local optical path, contributing to overall wide field of view and high resolution
2Manufacturing precision
If lens elements are added to improve resolution, then optical performance improves, but total lens length increases
Solution Approach 1:
The patent optimizes specific parameters including the ratio BFL/TTL (0.25-0.45) and f/TTL (0.1-0.55), refractive indices (Nd values between 1.45-1.75), and surface curvature radii. These parameter optimizations enable high resolution with controlled total lens length by precisely tuning the optical properties of each lens element rather than simply adding more elements
Solution Approach 2:
The six lens elements are arranged in a compact nested configuration along the optical axis, with each subsequent lens positioned to optimize space utilization. The lens elements overlap in their functional zones, allowing the light path to be folded efficiently and reducing the overall total lens length while maintaining the resolution benefits of multiple optical elements
3Adaptability or versatility
If lens curvature and refractive power are optimized for wide field of view, then field of view increases, but optical aberrations worsen
Solution Approach 1:
The patent converts the harmful effect of wide-angle aberrations into beneficial optical performance by strategically assigning negative refractive power to the first lens and alternating positive/negative powers among subsequent lenses. This configuration transforms what would normally be distortion-prone wide-angle optics into a system that achieves wide field of view while correcting aberrations through the complementary arrangement of diverging and converging lens elements
Solution Approach 2:
Instead of using conventional positive-power lens arrangements, the patent inverts the approach by starting with a negative-power first lens and alternating the refractive powers of subsequent elements. This inverted configuration allows wide field of view to be achieved while the alternating sign pattern of refractive powers naturally corrects the aberrations that would otherwise be exacerbated by wide-angle design
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 solution provides a lens assembly with improved optical performance, including corrected aberrations, increased field of view, and enhanced resolution, while ensuring the lenses are manufacturable and cost-effective.
Implementation Method 1
The first lens is with negative refractive power and includes a convex surface facing the object side and a concave surface facing the image side. The second, third and fourth lens are with refractive power. The fifth lens is with positive refractive power and includes a convex surface facing the image side. The sixth lens is with refractive power.
Data Source
AI summary
A lens assembly includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens, all of which are arranged in sequence from an object side to an image side along an optical axis. The first lens is with negative refractive power. The second, third, fourth and sixth lens are with refractive power. The fifth lens is with positive refractive power. The lens assembly satisfies: 0.078≦BFL/TTL≦0.4, 0.01≦f/TTL≦0.61, (Nd1+Nd2+Nd3+Nd4+Nd5+Nd6)/6<(Nd2+Nd3)/2 wherein BFL is a distance from an image side surface of the sixth lens to an image plane along the optical axis, TTL is a distance from the convex surface of the first lens to the image plane along the optical axis, f is an effective focal length of the lens assembly, and Nd1, Nd2, Nd3, Nd4, Nd5 and Nd6 are indexes of refraction of the first, second, third, fourth, fifth and sixth lenses.