Five-Lens Optical System with Aspheric Surfaces for Compact Design
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Solution Overview
Problem
Existing optical systems for compact digital cameras or mobile communication terminals face challenges in achieving both small size and high performance, particularly in the arrangement and refractive powers of lenses, which affect image quality and focal length.
Innovation Solution
The optical system is designed with first to fifth lenses sequentially arranged, where specific refractive indices, Abbe numbers, and refractive powers are optimized, along with aspheric surfaces and an aperture to adjust focal lengths and incident angles, ensuring improved performance and compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of lenses is increased to improve image quality, then image quality is improved, but the overall size of the optical system increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the refractive indices, Abbe numbers, and refractive powers of each lens element. The fifth lens has a refractive index between 1.6 and 1.7 and an Abbe number between 20 and 30, while the fourth lens has a refractive index between 1.5 and 1.6 and an Abbe number between 30 and 40. These specific parameter ranges enable the five-lens system to achieve high image quality while maintaining a compact form factor with a total length less than 5.0 mm.
Solution Approach 2:
The patent utilizes aspheric surfaces on the object-side and image-side of each lens element to control light rays in multiple dimensions. The aspheric coefficients (A2, A4, A6, A8) are optimized to correct spherical aberration and other optical distortions, enabling compact lens design with improved image quality without simply increasing the linear dimensions of the optical system.
2Volume of moving object
If the refractive power of lenses is increased to reduce optical system size, then compactness is improved, but spherical aberration and other optical distortions worsen
Solution Approach 1:
The patent applies local quality by assigning different refractive powers and material properties to each lens element based on its specific position and function in the optical system. The second lens has a refractive power between +1.0 and +3.0, the third lens between -2.0 and -0.5, and the fifth lens between +2.0 and +4.0. Each element's local optical properties are optimized to correct specific aberrations while contributing to the overall compact design.
Solution Approach 2:
The patent uses composite material approaches by combining lens elements with different refractive indices and Abbe numbers. The fourth lens uses material with refractive index 1.5-1.6 and Abbe number 30-40, while the fifth lens uses material with refractive index 1.6-1.7 and Abbe number 20-30. This composite approach allows the system to achieve high refractive power for compactness while correcting chromatic and spherical aberrations through material diversity.
3Volume of moving object
If the distance between lens surfaces is reduced to make the system more compact, then compactness is improved, but light ray control and focus precision deteriorate
Solution Approach 1:
The patent extensively uses aspheric surfaces with precisely controlled curvatures to maintain focus precision in a compact design. Each lens element has aspheric coefficients (A2, A4, A6, A8) that define the surface curvature profile, enabling the system to control light ray paths effectively despite reduced spacing between elements. The aspheric shapes allow for precise focal point control within the constrained optical path length.
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 design results in a compact optical system with enhanced performance by optimizing lens arrangements and refractive properties, reducing the distance between the first and fifth lens surfaces while maintaining effective focus length, thus preventing image shading and ensuring high image quality.
Implementation Method 1
the first to fifth lenses sequentially arranged from an object side to an image side... n2 represents a refractive index of the second lens... v2 represents an abbe number of the second lens... v3 represents an abbe number of the third lens
Data Source
AI summary
Disclosed is an optical system. The optical system includes first to fifth lenses sequentially arranged from an object side to an image side. The optical system satisfies 1.5<n2<1.55, 50<v2<70, and 20<v3<30 in which n2 represents a refractive index of the second lens, v2 represents an abbe number of the second lens, and v3 represents an abbe number of the third lens.