Five-Element Aspheric Lens Assembly for Wide Field of View
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Solution Overview
Problem
Conventional compact optical lens systems, such as those with a four-element or five-element lens structure, fail to meet the increasing demands for high resolution and image quality in portable electronic devices, particularly due to restricted field of view and pronounced distortion.
Innovation Solution
An imaging lens assembly comprising a specific configuration of five lens elements with varying refractive powers and aspheric surfaces, including a concave object-side surface for the first lens element, positive refractive power for the third lens element, negative refractive power for the fourth lens element, and a convex to concave surface transition on the fifth lens element, optimized to enhance field of view and correct aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional four-element lens structure is used, then the device complexity is reduced, but the field of view is restricted and distortion is pronounced
Solution Approach 1:
The patent divides the optical system into five distinct lens elements instead of four, with each element having specific refractive power and surface characteristics. This segmentation allows independent optimization of each element's function, enabling the first element to provide negative refractive power for expanded field of view while other elements correct aberrations, thus resolving the contradiction between structural simplicity and field of view requirements
Solution Approach 2:
The patent applies local quality by giving different surface characteristics to different regions of the lens elements. Specifically, the object-side surface of the first lens element is made concave at the paraxial region to expand field of view, while aspheric surfaces are applied to specific elements to correct distortion and aberrations in different field regions, allowing each local region to optimize its function
2Ease of manufacture
If the object-side surface of the first lens element is convex, then the manufacturing is easier, but the field of view is restricted
Solution Approach 1:
The patent inverts the conventional design by making the object-side surface of the first lens element concave instead of convex. This inversion allows the first element to provide negative refractive power, which expands the field of view. The aspheric surface design compensates for the increased manufacturing difficulty by providing precise control over light paths despite the non-conventional concave geometry
3Adaptability or versatility
If a conventional five-element lens structure is used, then the field of view can be enlarged, but the distortion is more pronounced and image quality suffers
Solution Approach 1:
The patent applies local quality by strategically placing aspheric surfaces on specific lens elements (first, second, and fifth elements) to correct distortion and aberrations in different field regions. The aspheric surfaces are designed with specific mathematical profiles that locally adjust the refraction of light rays, correcting distortion in peripheral regions while maintaining image quality across the entire field of view
Solution Approach 2:
The patent employs parameter changes by carefully controlling the refractive powers, curvature radii, and thicknesses of each lens element within specific ranges. The aspheric surface parameters are optimized to balance field of view expansion with distortion correction, allowing the system to achieve both wide field of view and high image quality through precise parameter 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 proposed lens assembly significantly enlarges the field of view, reduces distortion, and corrects various aberrations, thereby improving image quality and meeting the high-resolution requirements for compact optical systems in portable devices.
Implementation Method 1
The object-side surface and an image-side surface of the first lens element are aspheric
Implementation Method 2
the first lens element with negative refractive power has an object-side surface being concave at a paraxial region thereof
Implementation Method 3
The first lens element with negative refractive power has an object-side surface being concave at a paraxial region thereof
Implementation Method 4
the object-side surface of the fifth lens element changes from convex at the paraxial region thereof to concave at a peripheral region thereof
Data Source
AI summary
An imaging lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with negative refractive power has an object-side surface being concave at a paraxial region thereof, wherein the surfaces thereof are aspheric. The second lens element has refractive power. The third lens element has positive refractive power. The fourth lens element has negative refractive power. The fifth lens element with positive refractive power has an object-side surface being convex at a paraxial region thereof and an image-side surface being concave at a paraxial region thereof, wherein the object-side surface thereof changes from convex at the paraxial region thereof to concave at a peripheral region thereof, and the surfaces thereof are aspheric.