Seven-Element Imaging Lens With Aspheric Aberration Correction
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Solution Overview
Problem
Conventional optical systems struggle to balance high image quality, low sensitivity, proper aperture size, miniaturization, and desirable field of view due to advancements in semiconductor technology and increasing functionality requirements.
Innovation Solution
An imaging optical lens system with seven lens elements, including specific refractive powers, aspheric surfaces, and an aperture stop configuration, optimized by various geometric and refractive conditions, to achieve improved image quality and field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of lens elements is increased to improve image quality, then image quality is improved, but device complexity and size increase
Solution Approach 1:
The lens system is divided into seven distinct lens elements with specific refractive power assignments (first, second, and sixth elements with negative refractive power; third, fourth, and fifth elements with positive refractive power; seventh element with either positive or negative refractive power). Each element is strategically positioned and designed with specific surface curvatures and aspheric coefficients to correct different types of optical aberrations, thereby achieving high image quality through systematic segmentation of optical functions
Solution Approach 2:
The patent employs aspheric surfaces on multiple lens elements to correct optical aberrations. Specifically, the first lens element has an aspheric object-side surface, the second lens element has aspheric surfaces on both sides, the fourth lens element has an aspheric image-side surface, and the seventh lens element has an aspheric object-side surface. These aspheric designs enable precise control of light paths while maintaining compact element sizes
2Use of energy by moving object
If the aperture size is increased to improve light gathering capability, then sensitivity is improved, but depth of field control and aberration correction become more difficult
Solution Approach 1:
The patent implements localized quality optimization by assigning different refractive powers and surface characteristics to specific lens elements. The aperture stop is positioned between the second and third lens elements to locally control light distribution. The aspheric surfaces on specific elements (first, second, fourth, and seventh) provide localized aberration correction tailored to regions of high light concentration, enabling the system to maintain image quality across varying aperture conditions
3Adaptability or versatility
If the field of view is expanded to capture more scene information, then functionality is improved, but distortion and aberration increase
Solution Approach 1:
The optical system segments the field of view management across seven lens elements with differentiated functions. The negative refractive power elements (first, second, sixth) handle peripheral light rays to expand field of view, while positive refractive power elements (third, fourth, fifth) and the seventh element correct distortion in specific zones. The aperture stop between elements 2 and 3 segments the light path to control vignetting and distortion
Solution Approach 2:
Aspheric surfaces are strategically placed on lens elements handling different field regions. The first lens element's aspheric object-side surface corrects barrel distortion in wide-angle regions, while the fourth lens element's aspheric image-side surface corrects pincushion distortion in central regions, enabling expanded field of view with controlled aberrations
4Volume of moving object
If the lens system is miniaturized to reduce device size, then compactness is improved, but optical performance and image quality deteriorate
Solution Approach 1:
The patent extensively uses aspheric surfaces to achieve compact design without sacrificing image quality. The aspheric profiles enable steeper surface curvatures in a shorter axial distance, allowing the seven-element system to achieve high image quality with reduced total track length. Specifically, the aspheric surfaces on the first, second, fourth, and seventh lens elements enable aggressive miniaturization while correcting spherical aberration and maintaining focus precision
Solution Approach 2:
The lens elements are arranged in a compact nested configuration where elements with negative refractive power (first, second, sixth) are interspersed with positive refractive power elements (third, fourth, fifth). This nesting allows opposing optical powers to be closely spaced, reducing the overall optical path length while maintaining the necessary aberration correction sequence
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 enhanced image quality, increased field of view, and reduced size while maintaining sensitivity, addressing the challenges of conventional systems.
Implementation Method 1
The seven lens elements are, in order from an object side to an image side along an optical path, 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. Each of the seven lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side.
Data Source
AI summary
An imaging optical lens system includes seven lens elements which are, in order from an object side to an image side along an optical path: 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. Each of the seven lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The second lens element with negative refractive power has the object-side surface being concave in a paraxial region thereof, and at least one lens surface of the second lens element is aspheric. The image-side surface of the sixth lens element is concave in a paraxial region thereof. The imaging optical lens system further includes an aperture stop located between the second lens element and the third lens element.