Seven-Element Imaging Lens for Low-Profile Aberration Correction
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Solution Overview
Problem
Conventional imaging lenses struggle to achieve a balance between low profile and low F-number while effectively correcting aberrations, particularly in peripheral areas, leading to suboptimal optical performance.
Innovation Solution
The imaging lens configuration includes a series of lenses with specific refractive powers and aspheric surfaces, such as a first lens with a convex object-side surface and a fifth lens with a convex image-side surface, along with various conditional expressions to optimize aberration correction, ensuring a total track length to diagonal length ratio of 0.80 or less and an F-number of 2.1 or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If conventional imaging lens configurations are used, then the lens can achieve a low profile and low F-number, but aberrations in the peripheral area cannot be corrected effectively
Solution Approach 1:
The imaging lens is divided into seven separate lens elements with specific refractive powers and surface curvatures. Each lens element (first through seventh lenses) is designed with particular characteristics to correct specific aberrations, allowing the system to achieve both low profile and effective aberration correction in the peripheral area.
Solution Approach 2:
Different lens elements are assigned specific functions to correct different types of aberrations in different regions. The first lens corrects spherical aberration, the second and third lenses address coma and astigmatism, while the seventh lens specifically targets peripheral distortion, ensuring local optimization throughout the optical path.
2Illumination intensity
If conventional imaging lens configurations are used, then the lens can achieve a low F-number, but excellent optical performance cannot be obtained
Solution Approach 1:
The patent specifies precise parameter ranges for each lens element, including refractive powers (positive or negative), surface curvature radii, and thicknesses. These parameters are optimized to achieve an F-number of 2.1 or less while maintaining excellent optical performance through systematic control of light paths and focal properties.
Solution Approach 2:
The imaging lens employs a composite optical system combining seven different lens elements with varying refractive indices and dispersion properties. This composite structure enables the system to achieve low F-number with high optical performance by leveraging the complementary characteristics of each lens material and design.
3Length of stationary object
If conventional imaging lens configurations are used, then the lens can achieve a low profile, but aberrations cannot be corrected well balance
Solution Approach 1:
The patent utilizes aspheric surfaces on multiple lens elements, including the first lens with a convex object-side surface and the fifth lens with a convex image-side surface. These curved surfaces are mathematically optimized to correct spherical aberration, coma, and other distortions while maintaining a compact total track length ratio of 0.80 or less.
Solution Approach 2:
The patent addresses aberration correction by introducing dimensional complexity through aspheric surface profiles rather than simple spherical surfaces. This allows correction of multiple aberration types simultaneously within a compact form factor by varying the surface curvature in different radial zones of each lens element.
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 lens design achieves high resolution with balanced low profile and F-number, effectively correcting spherical aberration, coma aberration, astigmatism, field curvature, and distortion, while allowing for cost-effective manufacturing using plastic or glass materials.
Implementation Method 1
The first lens has the positive refractive power, aspheric surfaces on both sides, and the object-side surface being convex in the paraxial region. Therefore, spherical aberration, coma aberration, astigmatism, field curvature, and distortion are suppressed.
Implementation Method 2
The second lens has aspheric surfaces on both sides, and the coma aberration, the astigmatism, the field curvature, and the distortion are properly corrected.
Implementation Method 3
The seventh lens has the negative refractive power and aspheric surfaces on both sides. Therefore, chromatic aberration, the astigmatism, the field curvature, and distortion are properly corrected.
Data Source
AI summary
There is provided an imaging lens with excellent optical characteristics which satisfies demand of a low profile and a low F-number. An imaging lens comprises in order from an object side to an image side, a first lens with positive refractive power, a second lens, a third lens, a fourth lens, a fifth lens with positive refractive power, a sixth lens, and a seventh lens with negative refractive power, wherein said first lens has an object-side surface being convex in a paraxial region, and said fifth lens has an image-side surface being convex in a paraxial region, and predetermined conditional expressions are satisfied.