Wide-angle lens assembly with four-element optical design
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Solution Overview
Problem
Current wide-angle lens assemblies fail to simultaneously achieve a large field of view, small F-number, high resolution, and resistance to environmental temperature changes while maintaining good optical performance.
Innovation Solution
A wide-angle lens assembly comprising a meniscus lens with negative refractive power, a second lens with refractive power, a biconvex lens with positive refractive power, and a fourth lens, arranged along an optical axis, satisfying specific conditions to optimize field of view, F-number, resolution, and temperature resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the field of view is increased to achieve a large angle of view, then the field of view parameter is improved, but the F-number increases and resolution deteriorates
Solution Approach 1:
The lens assembly is divided into four distinct lens elements with different refractive powers and surface curvatures. The first lens has negative refractive power with a convex object-side surface, the second lens has positive refractive power, the third lens has negative refractive power, and the fourth lens has positive refractive power. This segmentation allows each lens to contribute differently to the overall optical performance, enabling large field of view while maintaining resolution through coordinated action of multiple specialized elements.
Solution Approach 2:
Each lens element is designed with specific local optical properties - different refractive powers, surface curvatures, and material characteristics. The first lens uses a convex object-side surface to handle peripheral rays, the second lens provides positive power for focal convergence, the third lens corrects aberrations with negative power, and the fourth lens fine-tunes the focal properties. This local optimization of optical quality in different zones enables simultaneous achievement of large field of view and high resolution.
2Illumination intensity
If the F-number is decreased to improve light gathering capability, then the F-number parameter is improved, but aberrations increase and optical performance deteriorates
Solution Approach 1:
The patent specifies precise parameter ranges for lens intervals and focal lengths to control aberrations while maintaining small F-number. The conditions 0.3 ≤ (CT2+CT3)/Td2 ≤ 1.1 and 0.25 ≤ (Td2-Td3)/TTL ≤ 0.38 optimize the spacing between lens elements to balance light gathering with aberration control. Additionally, the focal length ratios f1/f2 and f3/f4 are constrained to specific ranges to ensure proper optical power distribution across the four lenses, enabling small F-number operation with acceptable aberration levels.
Solution Approach 2:
The patent converts the potential harm of increased aberrations from small F-number operation into beneficial optical performance through the fourth lens. The fourth lens with positive refractive power is specifically designed to correct the aberrations introduced by the earlier lenses and the small aperture. By strategically placing this corrective element and optimizing its parameters, the design transforms the aberration problem into an opportunity for refined optical control, achieving both small F-number and high image quality.
3Stability of the object's composition
If the lens structure is modified to achieve temperature resistance, then the temperature stability is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent achieves temperature resistance through carefully selected parameter ranges for lens intervals and focal lengths. The conditions 1.0 ≤ f1/f2 ≤ 1.4 and 0.7 ≤ f3/f4 ≤ 0.9 optimize the optical power distribution to compensate for thermal expansion effects. The interval ratios (CT2+CT3)/Td2 and (Td2-Td3)/TTL are constrained to specific ranges that maintain optical alignment stability across temperature variations. These parameter optimizations provide passive thermal compensation without requiring active temperature control or complex thermal management structures.
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 effectively decreases the F-number, increases the field of view, enhances resolution, and corrects aberrations while resisting environmental temperature changes, improving assembly yield and optical performance.
Implementation Method 1
The first lens is a meniscus lens with negative refractive power, the second lens is with refractive power, the third lens is a biconvex lens with positive refractive power, and the fourth lens is with refractive power
Data Source
AI summary
A wide-angle lens assembly includes a first lens, a second lens, a third lens, and a fourth lens. The first lens is a meniscus lens with negative refractive power and includes a convex surface facing an object side and a concave surface facing an image side. The second lens is with refractive power and includes a concave surface facing the image side. The third lens is a biconvex lens with positive refractive power and includes a convex surface facing the object side and another convex surface facing the image side. The fourth lens is with refractive power. The first lens, the second lens, the third lens, and the fourth lens are arranged in order from the object side to the image side along an optical axis.