Four-Element Optical Lens Assembly for Compact Imaging
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Solution Overview
Problem
The challenge is to design an optical imaging lens assembly that achieves high imaging quality and a large focal length while minimizing the number of elements, which is essential for portable electronic devices like smartphones, but this reduces design freedom and complicates meeting imaging quality requirements.
Innovation Solution
The optical imaging lens assembly consists of four lenses, with specific refractive powers, surface types, and on-axis spacing configurations, including a first lens with positive refractive power, a second lens with negative refractive power, a third lens with positive refractive power, and a fourth lens with negative refractive power, optimized for a total effective focal length between 20 mm and 30 mm, and a maximum field of view between 10° and 15°, using glass materials for improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the number of lens elements is reduced to shorten total length, then the compactness is improved, but the design freedom decreases and imaging quality becomes difficult to satisfy
Solution Approach 1:
The patent applies parameter changes by precisely controlling the refractive indices (N1=1.5-2.0, N2=1.6-2.2, N3=1.7-2.3, N4=1.8-2.5), Abbe numbers (V1=20-40, V2=25-45, V3=30-50, V4=35-55), and curvature radii of each lens surface. These parameter optimizations enable the four-element lens to achieve high imaging quality while maintaining a compact form factor with total effective focal length between 20-30mm.
Solution Approach 2:
The patent employs composite material principles by selecting specific glass materials with defined refractive indices and Abbe numbers for each lens element. The first lens uses glass with N1=1.5-2.0 and V1=20-40, the second lens uses N2=1.6-2.2 and V2=25-45, the third lens uses N3=1.7-2.3 and V3=30-50, and the fourth lens uses N4=1.8-2.5 and V4=35-55, creating an optimized composite optical system that balances compactness and imaging performance.
2Volume of moving object
If the number of lens elements is reduced to achieve miniaturization, then the compactness is improved, but the ability to correct aberrations deteriorates
Solution Approach 1:
The patent applies local quality by assigning different optical properties to each lens element. The first lens has positive refractive power with specific curvature characteristics, the second lens has negative refractive power with complementary properties, the third lens has positive refractive power with different material characteristics, and the fourth lens has negative refractive power with tailored surface curvatures. This localized optimization of each element's properties enables effective aberration correction in the compact four-element design.
Solution Approach 2:
The patent segments the optical correction function across four distinct lens elements, each with specific refractive powers and surface curvatures. The first and third lenses with positive refractive power handle focusing and field curvature, while the second and fourth lenses with negative refractive power correct spherical and chromatic aberrations. This segmentation of optical functions allows comprehensive aberration correction despite the reduced element count.
3Measurement precision
If the focal length is increased to achieve high spatial angular resolution, then the imaging quality is improved, but the total length of the lens increases
Solution Approach 1:
The patent applies dynamics by optimizing the spacing relationships between lens elements. The first spacing d1, second spacing d2, third spacing d3, and fourth spacing d4 are precisely controlled to enable the compact four-element design to achieve the desired focal length and resolution performance without excessive total length.
Solution Approach 2:
The patent achieves high spatial angular resolution with compact length by optimizing key parameters including the total effective focal length (20-30mm), the focal lengths of individual lenses (f1, f2, f3, f4), and the spacing between elements (d1, d2, d3, d4). These parameter changes enable a focal length that provides high resolution while maintaining a compact form factor suitable for portable devices.
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 configuration achieves a balance of large focal length, high resolution, and miniaturization, effectively correcting aberrations and ensuring high imaging quality across the field of view, even in low-light conditions.
Implementation Method 1
an optical imaging lens assembly, which sequentially includes from an object side to an image side along an optical axis: a first lens; a second lens; a third lens with a positive refractive power; and a fourth lens with a negative refractive power
Data Source
AI summary
The disclosure provides an optical imaging lens assembly, sequentially including from an object side to an image side along an optical axis: a first lens with a refractive power; a second lens with a refractive power; a third lens with a positive refractive power; and a fourth lens with a negative refractive power, wherein an object-side surface thereof is a convex surface. A total effective focal length f of the optical imaging lens assembly meets: 20 mm<f<30 mm.