Seven-Lens Optical System Aberration Correction
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Solution Overview
Problem
Conventional compact optical systems with fewer lens elements fail to meet the demands for high image quality and compact size while maintaining a large aperture and image sensor, leading to suboptimal performance in portable electronic devices.
Innovation Solution
A photographing system comprising seven lens elements with specific refractive powers and surface curvatures, including a first lens element with positive refractive power and convex object-side surfaces, a second lens element with negative refractive power and concave image-side surfaces, and a seventh lens element with negative refractive power and concave object-side surfaces, arranged with air gaps between each element to enhance image quality and compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the number of lens elements is reduced to achieve compact size, then the device size is reduced, but the image quality and resolution deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the refractive indices, curvature radii, and thickness of each lens element. Specific parameter ranges are defined (e.g., 1.45 < n1 < 1.70, 0.30f < R12 < 1.50f) to achieve the desired balance between compact size and high image quality, allowing the optical system to maintain performance while reducing overall dimensions
Solution Approach 2:
The patent utilizes aspheric surfaces on multiple lens elements (first, sixth, and seventh lens elements) to correct optical aberrations. The aspheric coefficients are specifically designed to reduce spherical aberration and other distortions, enabling high image quality in a compact configuration where conventional spherical lenses would fail
2Manufacturing precision
If more lens elements are added to improve image quality, then the image quality improves, but the optical system size and complexity increase
Solution Approach 1:
The patent assigns multiple functions to individual lens elements. For example, the first lens element simultaneously provides positive refractive power for focusing and features an aspheric surface for aberration correction. The sixth and seventh elements work together as a combined negative power group that addresses both focusing and distortion correction, reducing the need for additional separate elements
Solution Approach 2:
The patent applies aspheric surfaces selectively to specific lens elements (first, sixth, and seventh) rather than all elements, optimizing aberration correction where it is most needed while minimizing manufacturing complexity. The aspheric coefficients are tailored to the specific functional requirements of each element, providing localized quality improvement without uniform complexity increase
3Volume of moving object
If lens elements are cemented together to reduce air gaps, then the optical system becomes more compact, but chromatic aberrations increase
Solution Approach 1:
The patent introduces air gaps between lens elements as an intermediary space that allows for chromatic aberration correction. These air gaps enable the use of different glass materials with varying dispersion properties (Abbe numbers) in adjacent elements, allowing chromatic aberrations to be balanced and corrected while maintaining a compact overall structure through careful spacing 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 system achieves improved image quality, reduced aberrations, and a compact size by effectively distributing refractive power and correcting chromatic aberrations, while maintaining a large aperture and image sensor, suitable for high-resolution imaging in portable electronic devices.
Implementation Method 1
a first lens element 110 with positive refractive power, a second lens element 120 with negative refractive power, a third lens element 130 with positive refractive power, a fourth lens element 140 with negative refractive power, a fifth lens element 150 with positive refractive power, a sixth lens element 160 with positive refractive power and a seventh lens element 170 with negative refractive power
Data Source
AI summary
A photographing system 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, a fifth lens element, a sixth lens element and a seventh lens element with refractive power. The first lens element with positive refractive power has an object-side surface being convex in paraxial region. The second lens element with refractive power has an image-side surface being concave in paraxial region. The third, fourth and fifth lens elements all have refractive powers. The sixth lens element with refractive power has an image-side surface being concave in paraxial region, wherein the image-side surface has at least one convex shape in off-axis region, and both of two surfaces are aspheric. The seventh lens element with refractive power has an object-side surface being concave in paraxial region, and both of two surfaces are aspheric.