Three-Element Aspheric Lens Assembly for Compact Imaging
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Solution Overview
Problem
Conventional compact imaging lenses with two elements are insufficient for high-end photography due to limited aberration correction, while adding more elements increases size, making it difficult to maintain a compact form while achieving good image quality.
Innovation Solution
A photographing optical lens assembly comprising three lens elements with specific refractive powers and surface curvatures, including a bi-convex first lens, a concave-convex second lens, and a meniscus or bi-concave third lens with an inflection point, along with a stop between the object and second lens elements, to reduce total track length and correct aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If two lens elements are used to reduce production cost, then manufacturing cost is reduced, but aberration correction capability is insufficient
Solution Approach 1:
The patent changes the parameters of the lens elements by introducing aspheric surfaces with specific coefficients (A4, A6, A8, A10) and controlling the Abbe numbers (V1, V2, V3) within specific ranges. This allows effective aberration correction while maintaining only three lens elements, avoiding the need for more elements that would increase cost and complexity.
Solution Approach 2:
The patent uses lens elements with different Abbe numbers (V1, V2, V3) to create a composite optical system that corrects chromatic and spherical aberrations. The specific combination of materials with different optical properties enables effective aberration correction without requiring additional lens elements.
2Manufacturing precision
If three lens elements are used to correct aberrations, then image quality is improved, but total track length increases
Solution Approach 1:
The patent optimizes the parameters of the three lens elements including their thicknesses (CT1, CT2, CT3), radii of curvature (R1-R6), and aspheric coefficients to achieve effective aberration correction while keeping the total track length within a compact range suitable for mobile phone cameras.
Solution Approach 2:
The patent introduces aspheric surfaces with specific local curvature variations on each lens element. The aspheric coefficients (A4, A6, A8, A10) are optimized to correct aberrations locally at different zones of the lens, enabling effective correction with only three elements and reduced total track length.
3Manufacturing precision
If more lens elements are used to improve image quality, then aberration correction is enhanced, but device size increases
Solution Approach 1:
The patent uses advanced parameter optimization including aspheric coefficients (A4, A6, A8, A10) and Abbe number control (V1, V2, V3) to achieve superior image quality and aberration correction with only three lens elements. This avoids the need for additional elements that would increase the lens assembly volume.
Solution Approach 2:
The patent divides the optical system into three strategically designed lens elements, each with specific functions. The first lens element (positive power) handles initial light convergence, the second lens element (negative power) corrects aberrations, and the third lens element (positive power) provides final focusing. This segmentation achieves comprehensive aberration correction with minimal 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
This configuration enhances image quality, reduces the lens assembly's size, and improves resolution by effectively correcting aberrations and maintaining a compact form, suitable for portable electronic devices.
Implementation Method 1
a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface
Implementation Method 2
a second lens element with positive refractive power having a concave object-side surface and a convex image-side surface, the object-side and image-side surfaces thereof being aspheric
Implementation Method 3
a third lens element with negative refractive power having a concave image-side surface on which at least one inflection point is formed, the object-side and image-side surfaces thereof being aspheric
Data Source
AI summary
This invention provides a photographing optical lens assembly comprising, in order from an object side to an image side: a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface; a second lens element with positive refractive power having a concave object-side surface and a convex image-side surface, both of the two surfaces being aspheric; a third lens element with negative refractive power having a concave image-side surface on which at least one inflection point is formed, both of the two surfaces being aspheric; and a stop disposed between an imaged object and the second lens element; wherein there are only three lens elements with refractive power. Such an arrangement of optical elements can effectively reduce the size of the lens assembly, mitigate the sensitivity of the optical system and enable the lens assembly to obtain a higher resolution.