Five-Lens Optical System for Mobile Camera Miniaturization
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Solution Overview
Problem
Conventional optical lens systems for mobile phone cameras with four lens elements fail to provide high enough resolution while maintaining miniaturization, as the increasing pixel size of electronic imaging sensors requires better image quality and longer optical paths.
Innovation Solution
An optical lens system comprising five lens elements, including a first lens with strong positive refractive power, a second with negative refractive power for chromatic aberration correction, a third for refractive power distribution, and fourth and fifth elements as correction lenses, along with an aperture stop to control the total track length and improve image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of lens elements is increased to improve image quality and resolution, then image quality improves, but the total track length increases making miniaturization difficult
Solution Approach 1:
The optical system is segmented into five distinct lens elements with specific functions: first element for positive refractive power, second for negative refractive power and chromatic aberration correction, third for positive refractive power with specific surface curvatures, and fourth and fifth as correction elements. This functional segmentation allows each element to contribute efficiently to image quality while maintaining compact overall size
2Measurement precision
If the pixel size of electronic imaging sensors is reduced to increase resolution, then resolution improves, but the requirement for image quality and optical path length increases
Solution Approach 1:
The patent defines specific parameter relationships to address the increased image quality requirements from smaller pixels. The focal length ratios (f/f1, f/f2, f/f3) and refractive index differences are constrained to specific ranges that optimize light gathering and focusing efficiency, thereby achieving high resolution imaging with compact optical path length
Solution Approach 2:
The patent employs lens elements with different refractive indices (n1, n2, n3, n4, n5) and Abbe numbers (v1, v2, v3, v4, v5) to correct chromatic and spherical aberrations. This composite approach using materials with varying optical properties enables high resolution for small pixel sensors while maintaining a compact design through efficient aberration correction
3Measurement precision
If the number of lens elements is increased to satisfy higher resolution requirements, then resolution improves, but device complexity increases
Solution Approach 1:
The patent achieves high resolution with only five lens elements by optimizing key parameters such as focal length ratios (0.6 < f/f1 < 1.2, -2.0 < f/f2 < -0.5), refractive indices (1.5 < n1 < 1.7, 1.6 < n2 < 1.8), and curvature radii relationships. This parameter optimization allows the system to achieve superior resolution without increasing the number of elements, thereby reducing device complexity
Solution Approach 2:
Each lens element in the five-element system performs multiple functions: the first element provides positive refractive power and contributes to chromatic aberration correction; the second element provides negative refractive power and corrects spherical aberration; the third element with its specific surface curvatures addresses field curvature; and the fourth and fifth elements serve as correction elements. This multi-functionality reduces the total number of elements needed while maintaining high resolution
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 five-lens system enhances image quality, maintains miniaturization, and reduces the total track length, ensuring better light incidence angles for improved photosensitivity and correcting aberrations, while allowing for the use of plastic lens elements for cost-effective production.
Implementation Method 1
a first lens element with positive refractive power having a convex object-side surface
Implementation Method 2
The second lens element with negative refractive power mainly serves to correct the chromatic aberration
Implementation Method 3
an aperture stop being located between an object to be photographed and the second lens element
Data Source
AI summary
An optical lens system for taking image comprises, in order from the object side to the image side: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power; a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface; a fourth lens element with positive refractive power; a fifth lens element with refractive power; and an aperture stop located between an object to be photographed and the second lens element. In the optical lens system for taking image, the number of the lens elements with refractive power being limited to five. Such lens arrangements can effectively reduce the volume of the optical lens system, reduce the sensitivity of the optical lens system and obtain higher resolution.