Five-Element Optical Lens System for Compact Wide-Angle Imaging
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Solution Overview
Problem
Current optical lens systems for electronic devices face challenges in achieving a compact size, wide angle of view, small F number, high image quality, low sensitivity to assembly tolerance, and low material costs, while also addressing issues of length, F number, and image edge quality.
Innovation Solution
A five-piece optical lens system comprising specific refractive power distributions and aspheric surfaces, including a stop, first, second, third, fourth, and fifth lens elements, with carefully controlled focal lengths and refractive indices to optimize miniaturization, image quality, and cost, while maintaining a small F number and wide angle of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple lens elements are used to improve resolution and image quality, then image quality is improved, but the system length increases and F number becomes larger
Solution Approach 1:
The patent employs aspheric surfaces on multiple lens elements (first, second, fourth, and fifth lens elements) to change the geometric parameters of the optical system. This allows for better control of light paths, enabling reduced system length and F number while maintaining high image quality through improved aberration correction compared to traditional spherical surfaces
Solution Approach 2:
The patent uses lens elements with different refractive indices and Abbe numbers (e.g., first lens element with Nd1=1.544, Vd1=55.9; second lens element with Nd2=1.632, Vd2=23.4) to create a composite optical system. This combination of materials with varying optical properties enables compact design while achieving high resolution and image quality through differential refraction and aberration management
2Illumination intensity
If high refractive material is used to achieve smaller F number, then F number is reduced, but manufacturing cost increases
Solution Approach 1:
The patent achieves a small F number (Fno=2.05) not through high refractive index materials alone, but through optimization of multiple parameters including aspheric surface coefficients (k, A4, A6, A8, A10, A12, A14), lens element positions, and thicknesses. This approach allows using conventional materials (Nd=1.544, 1.632) while achieving excellent light gathering capability and image quality without the high costs associated with exotic high-refractive materials
Solution Approach 2:
The patent replaces traditional spherical surfaces with aspheric surfaces on multiple lens elements, enabling more efficient light path control and focal point convergence. This geometric modification allows achieving small F number with standard materials by optimizing surface curvature profiles rather than relying on high refractive index materials, thereby reducing manufacturing costs
3Illumination intensity
If single high refractive material piece is used to provide smaller F number, then F number is reduced, but chief ray angle at image edge becomes too large affecting image quality
Solution Approach 1:
The patent divides the optical system into five distinct lens elements with alternating positive and negative refractive powers, rather than using a single element. This segmentation allows different zones of the optical system to handle different aspects of light control: central elements manage on-axis focus while peripheral elements and aspheric surfaces control off-axis chief rays, thereby maintaining small F number while preserving image edge quality through distributed optical function
Solution Approach 2:
The patent applies aspheric surfaces selectively to specific lens elements (first, second, fourth, and fifth) rather than uniformly to all elements or using a single homogeneous design. This localized application of aspheric correction targets specific aberration problems in different regions of the optical field, enabling optimal control of chief ray angles at image edges while maintaining small F number through region-specific optical optimization
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 system achieves a compact form, high image quality, reduced sensitivity to assembly tolerance, and lower manufacturing costs, enabling clear images even in low light conditions with a wide angle of view.
Implementation Method 1
a first lens element with a positive refractive power having an aspheric convex object-side surface and an aspheric convex image-side surface
Implementation Method 2
both of the object-side surface and the image-side surface of the first lens element being aspheric
Implementation Method 3
a second lens element with a negative refractive power having a meniscus shape, and a concave image-side surface
Implementation Method 4
at least one inflection point being formed on the image-side surface of the fifth lens element
Data Source
AI summary
An optical lens system having a small F number, a wide angle of view, a short total length and a low manufacturing cost, includes, in order from an object side to an image side: a stop; a first lens element with a positive refractive power; a meniscus second lens element with a negative refractive power; a third lens element with a positive refractive power; a fourth lens element with a positive refractive power; a fifth lens element with a negative refractive power, the optical lens system has a focal length of f, the first lens element has a focal length f1, the third lens element has a focal length f3, the fourth lens element has a focal length f4, the fifth lens element has a focal length f5, and they satisfy the conditions: 0.4<f4/f<1.0; −0.8<f5/f<−0.4; and f1/f<1.2<f3/f.