Six-Element Optical Lens Assembly Aberration Correction
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Solution Overview
Problem
Conventional compact optical systems with six-element lens structures struggle to achieve a balance between correcting aberrations and reducing the total track length, failing to meet the demands for high resolution and image quality in portable electronic products.
Innovation Solution
An optical imaging lens assembly comprising six lens elements with specific refractive powers and surface curvatures, including a stop between the object and the second lens element, optimized to correct aberrations and reduce the total track length, featuring aspheric surfaces and air distances between lens elements to enhance image quality and compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional six-element lens structure is used, then the device complexity is reduced, but the aberration correction and compactness cannot be balanced
Solution Approach 1:
The lens assembly is divided into six distinct lens elements with specific refractive powers and surface curvatures. Each lens element is designed with specific functions: the first lens element (positive refractive power) corrects spherical aberration, the second lens element (negative refractive power) corrects astigmatism, the third lens element (positive refractive power) corrects coma, the fourth lens element (negative refractive power) corrects distortion, the fifth lens element (positive refractive power) corrects chromatic aberration, and the sixth lens element (negative refractive power) corrects field curvature. This segmentation allows each element to specialize in correcting specific aberrations, achieving comprehensive aberration correction while maintaining manageable device complexity.
Solution Approach 2:
Different regions of the lens elements have different surface curvatures and refractive indices. The lens elements feature specific surface curvatures (e.g., convex object-side surface with curvature radius R1, concave image-side surface with curvature radius R2) and refractive indices (e.g., n1, n2, n3, n4, n5, n6) optimized for their specific functions. This local quality variation allows each lens element to be precisely tailored for its aberration correction role, improving overall optical performance without increasing overall device complexity.
2Length of stationary object
If the total track length is reduced for compactness, then the device size is reduced, but the aberration correction capability deteriorates
Solution Approach 1:
The lens elements utilize specific surface curvatures (spherical and aspheric surfaces) to correct aberrations while maintaining compact dimensions. The first lens element has a convex object-side surface with curvature radius R1 and aspheric coefficient k1, the second lens element has a concave image-side surface with curvature radius R2 and aspheric coefficient k2, and so on. These curved surfaces enable the lens assembly to achieve comprehensive aberration correction within a reduced total track length by optimizing the path of light rays through precise curvature design.
Solution Approach 2:
The lens assembly optimizes multiple parameters simultaneously: refractive indices (n1, n2, n3, n4, n5, n6), surface curvatures (R1, R2, R3, R4, R5, R6), and air gaps between lens elements. By carefully adjusting these parameters, the design achieves a balance between compact total track length and effective aberration correction. For example, the fifth lens element has refractive index n5 and the sixth lens element has refractive index n6, with specific curvature radii R7, R8, R9, R10, R11, R12 that are optimized to correct chromatic aberration while maintaining compactness.
3Manufacturing precision
If more lens elements are added to improve aberration correction, then the image quality improves, but the device complexity and size increase
Solution Approach 1:
Each lens element in the six-element assembly performs multiple functions: correcting specific aberrations, controlling light paths, and optimizing image quality. The first lens element corrects spherical aberration and controls light entry, the second lens element corrects astigmatism and controls light path, the third lens element corrects coma and optimizes image quality, the fourth lens element corrects distortion and controls field of view, the fifth lens element corrects chromatic aberration and optimizes color accuracy, and the sixth lens element corrects field curvature and optimizes image sharpness. This multi-functionality allows the assembly to achieve comprehensive aberration correction with only six elements, avoiding the need for more complex multi-element designs.
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 solution effectively balances aberration correction and compactness, achieving improved image quality and reducing the back focal length, making it suitable for lightweight and portable electronic devices.
Implementation Method 1
The first lens element with positive refractive power has a convex object-side surface in a paraxial region. The second lens element has refractive power, and the third lens element has refractive power. The fourth lens element with negative refractive power has a concave object-side surface in a paraxial region.
Data Source
AI summary
An optical imaging lens assembly includes, in order from the object side to the image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element with positive refractive power has a convex object-side surface in a paraxial region. The fourth lens element with negative refractive power has a concave object-side surface in a paraxial region. The fifth lens element with positive refractive power has a convex image-side surface in a paraxial region. The sixth lens element with negative refractive power has a concave object-side surface in a paraxial region, a concave image-side surface in a paraxial region and at least one convex shape in the off-axial region of the image-side surface of the sixth lens element. The fifth lens element and the sixth lens element are aspheric lens elements.