Three-Lens Photographing Optical System Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional compact photographing optical systems face challenges in achieving high image quality while maintaining a short total track length, particularly in portable electronics, due to limitations in aberration correction and increased sensitivity.
Innovation Solution
A photographing optical system comprising three lens elements with specific refractive powers and surface curvatures, including a first lens with positive refractive power, a second lens with negative refractive power, and a third lens with aspheric surfaces and inflection points, optimized by the placement of a stop between the object and the first lens element, to reduce total track length and correct aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a two-lens structure is used to reduce manufacturing costs, then manufacturing cost is reduced, but aberration correction ability is limited and image quality is insufficient
Solution Approach 1:
The optical system is segmented into three distinct lens elements with different refractive powers and surface characteristics. The first lens has positive refractive power with aspheric surfaces, the second lens has negative refractive power with aspheric surfaces, and the third lens has positive refractive power with aspheric surfaces. This segmentation allows each lens to perform specific functions in aberration correction while maintaining overall system compactness.
Solution Approach 2:
The patent applies parameter changes by optimizing the refractive indices, curvatures, and thicknesses of the three lens elements. Specifically, the aspheric coefficients and inflection points of the lens surfaces are carefully adjusted to achieve superior aberration correction. The stop position and lens spacing are also optimized to balance image quality with compact total track length.
2Manufacturing precision
If too many lens elements are used to improve image quality, then aberration correction is improved, but total track length increases and compactness is lost
Solution Approach 1:
Each lens element is designed with specific local characteristics: the first lens has aspheric surfaces with specific inflection points, the second lens has aspheric surfaces with negative refractive power, and the third lens has aspheric surfaces with positive refractive power. This local quality differentiation allows efficient aberration correction within a compact three-element structure.
Solution Approach 2:
The patent extensively uses aspheric surfaces with specific curvatures and inflection points for all three lens elements. The aspheric coefficients are optimized to reduce aberrations while maintaining compact lens spacing. The curved surfaces enable better light path management within the constrained total track length.
3Length of moving object
If three positive refractive lens elements are used, then compactness is maintained, but aberration correction (especially chromatic aberration) is difficult and image quality is compromised
Solution Approach 1:
The optical system introduces asymmetry by using a mix of positive and negative refractive power lens elements rather than three identical positive elements. The second lens with negative refractive power creates an asymmetric refractive power distribution that enables effective chromatic aberration correction while maintaining compact total track length.
Solution Approach 2:
The system uses composite optical design combining lenses with different refractive powers and dispersion characteristics. The first, second, and third lenses have different refractive indices and aspheric coefficients, creating a composite optical system that achieves both compactness and superior aberration correction including chromatic aberration.
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 effectively reduces the total track length, improves image quality by correcting aberrations, and enhances photosensitivity by positioning the exit pupil far from the image plane, achieving a favorable balance between telecentric feature and wide angle of view.
Implementation Method 1
a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power having a convex object-side surface and a concave image-side surface
Data Source
AI summary
This invention provides a photographing optical system comprising: in order from an object side to an image side: a first lens with positive refractive power having a convex object-side surface; a second lens with negative refractive power having a convex object-side surface and a concave image-side surface, at least one of the object-side and image-side surfaces thereof being aspheric; a third lens having at least one inflection point formed thereon and both surfaces thereof being aspheric. A stop is positioned between an imaged object and the first lens element. The photographing optical system further comprises an electronic sensor on which an object is imaged, and there are three lens elements of the photographing optical system with refractive power.