Six-Lens Optical Imaging Structure for Thin Low-F-Number Cameras
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Solution Overview
Problem
Existing optical imaging systems with a small number of lenses face challenges in achieving high resolution while maintaining a thin width, particularly in camera modules for portable devices.
Innovation Solution
An optical imaging system comprising six lenses with specific refractive powers and surface configurations, including concave and convex surfaces, and satisfying certain conditional expressions to optimize aberration correction and miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a small number of lenses (four or less) is used in the optical imaging system, then the width of the camera module is reduced, but the resolution and optical performance deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the refractive indices, curvatures, and thicknesses of each lens element. Specifically, it uses a combination of positive and negative refractive powers with precise control of focal lengths and surface curvatures to achieve high resolution with only six lenses, resolving the contradiction between lens count and optical performance
Solution Approach 2:
The optical system is segmented into six distinct lens elements with specific functions: the first lens (positive power) for initial convergence, the second lens (negative power) for divergence and aberration correction, the third lens (positive power) for intermediate focusing, the fourth lens (negative power) for aberration control, the fifth lens (positive power) for final convergence, and the sixth lens (positive power with inflection point) for fine-tuning. This segmentation allows each element to contribute optimally to the overall resolution while maintaining a compact form factor
2Length of stationary object
If the F number is reduced to enable miniaturization, then the camera module size is reduced, but the light gathering ability and image quality deteriorate
Solution Approach 1:
The patent achieves a low F number (F<2.2) by optimizing the aperture diameter to focal length ratio while maintaining excellent aberration correction. The specific parameter optimization includes controlling the focal lengths of individual lenses and their spacing to achieve both miniaturization and high light gathering ability simultaneously
Solution Approach 2:
Each lens element is designed to perform multiple functions: the first lens converges light and begins aberration correction; the second lens diverges light while correcting spherical aberration; the third lens provides intermediate focusing and coma correction; the fourth lens controls astigmatism and field curvature; the fifth lens achieves final convergence and distortion correction; the sixth lens with its inflection point provides fine-tuned aberration control. This multi-functionality allows the system to achieve high performance with minimal elements
3Manufacturing precision
If six lenses with specific configurations are used to achieve high resolution, then the optical performance is improved, but the device complexity increases
Solution Approach 1:
The patent optimizes the parameters of six lens elements to achieve high resolution while keeping the total lens count manageable. The specific optimizations include refractive indices (n1, n2, n3, n4, n5, n6), focal lengths (f1, f2, f3, f4, f5, f6), and curvature radii (R1 through R24) that work together to maximize resolution with minimal complexity
Solution Approach 2:
The patent introduces an inflection point on the image-side surface of the sixth lens, creating a dynamic surface profile that optimizes aberration correction. This inflection point allows the lens surface to change curvature characteristics across different zones, achieving superior optical performance without adding more lens elements
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 high resolution with a low F number, effectively correcting aberrations and enabling miniaturization for thin-width camera modules.
Implementation Method 1
an optical imaging system includes a first lens having a positive refractive power and a concave an image-side surface
Data Source
AI summary
An optical imaging system includes a first lens having a positive refractive power, an image-side surface of the first lens being concave, a second lens, a third lens, an image-side surface of the third lens being concave, a fourth lens, a fifth lens, an image-side surface of the fifth lens being concave, and a sixth lens having a positive refractive power and having an inflection point formed on an image-side surface, wherein an F number of the optical imaging system is lower than 2.2.