Aspheric Imaging Lens Aberration Correction
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Solution Overview
Problem
Conventional imaging lenses face challenges in achieving a balance of wide field of view, low F-number, and low profileness while effectively correcting aberrations, particularly in the peripheral area.
Innovation Solution
The imaging lens configuration includes a first lens with negative refractive power, an aperture stop, a double-aspheric second lens, a fourth lens with positive refractive power, and a double-sided aspheric fifth lens, with specific conditional expressions defining the refractive indices, curvature radii, and focal lengths to optimize aberration correction and lens design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If conventional imaging lens configurations are used to achieve wide field of view and low F-number, then the field of view and light gathering capability are improved, but aberration correction in the peripheral area deteriorates
Solution Approach 1:
The patent applies aspherical surfaces to multiple lens elements (first lens object-side surface, second lens both surfaces, third lens image-side surface, fourth lens object-side surface) to correct peripheral aberrations. The aspherical shapes enable precise control of light ray paths across the wide field of view, resolving the contradiction between wide field of view and aberration correction by providing non-uniform curvature that compensates for off-axis optical errors.
Solution Approach 2:
The patent employs multiple lens elements with varying refractive indices (N1, N2, N3, N4) and specific curvature radii (r1, r2, r3, r4, r5, r6, r7, r8) to optimize optical performance. By carefully selecting and adjusting these parameters, the lens system achieves both wide field of view and excellent aberration correction, transforming the contradiction into a solvable parameter optimization problem.
2Use of energy by moving object
If conventional imaging lens configurations are used to achieve low F-number, then light gathering capability is improved, but lens complexity and profile increase
Solution Approach 1:
The patent divides the optical system into five distinct lens elements with specific refractive powers and aspherical surfaces. This segmentation allows each element to perform a specialized function in correcting specific aberrations while contributing to the overall low F-number performance, managing complexity through functional division rather than using a single complex element.
Solution Approach 2:
The patent uses lens materials with different refractive indices (N1=1.535, N2=1.635, N3=1.755, N4=1.612) to create a composite optical system. This allows optimization of light gathering capability through low F-number while managing complexity by selecting materials with favorable optical properties that reduce the need for excessive element count or size.
3Length of stationary object
If conventional imaging lens configurations are used to achieve low profileness, then compactness is improved, but aberration correction and optical performance deteriorate
Solution Approach 1:
The patent uses aspherical surfaces on multiple lens elements to achieve excellent aberration correction within a compact total track length of 4.31mm. The aspherical shapes enable more efficient light path control, allowing the optical system to achieve high optical performance without requiring increased lens element thickness or spacing that would increase the overall profile.
Solution Approach 2:
The patent optimizes specific parameter relationships including curvature radii (r1 through r8), refractive indices (N1 through N4), and focal lengths (f1 through f5) to achieve compact dimensions. By carefully balancing these parameters, the system maintains low profileness (TTL/f = 0.94) while achieving excellent optical performance with half field of view of 55.4 degrees and F-number of 2.3.
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 enables high-resolution imaging with a wide field of view, low profileness, and low F-number, while effectively correcting spherical aberrations, chromatic aberrations, and other optical distortions, ensuring excellent optical performance.
Implementation Method 1
a first lens having negative refractive power, an aperture stop, a second lens having positive refractive power
Implementation Method 2
a double-aspheric second lens, a fourth lens having positive refractive power, and a double-sided aspheric fifth lens
Data Source
AI summary
There is provided an imaging lens with high-resolution which satisfies the wide field of view, the low-profileness and the low F-number in well balance, and excellently corrects aberrations. An imaging lens comprises in order from an object side to an image side, a first lens having negative refractive power, an aperture stop, a second lens, a third lens being a double-aspheric lens, a fourth lens having positive refractive power, and a fifth lens being a double-sided aspheric lens, wherein a below expression is satisfied:−0.07<(N1−1)/(r1×f)×1000<0.07whereN1: refractive index at d-ray of the first lens,r1: curvature radius of the object-side surface of the first lens,f: focal length of the overall optical system.