Compact Lens Layout for Aberration-Corrected Imaging Optics
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Solution Overview
Problem
Conventional optical systems for digital cameras and imaging devices face challenges in achieving high resolution, large aperture, and low cost while maintaining a small size and light weight, particularly in correcting various aberrations with a limited number of lenses.
Innovation Solution
An optical system configuration with a front group and a rear group, each comprising specific lenses with positive and negative refractive powers, and adhering to conditional expressions to optimize refractive indices, distances, and curvatures, ensuring a total of eight or fewer lenses, including a concave surface on the object-side surface of the lens B and satisfying specific Abbe number and curvature ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a telephoto-type power arrangement with positive refractive power on the object side and negative refractive power on the image side is adopted to downsize the optical system, then the size and weight of the optical system are reduced, but it becomes difficult to satisfactorily correct various aberrations with a small number of lenses
Solution Approach 1:
The patent applies parameter changes by precisely controlling the refractive indices, Abbe numbers, and curvatures of the lenses. Specifically, it sets conditions on the refractive index ratios (NdLA/NdLB between 0.90-1.05), Abbe number ratios (νdLA/νdLB between 0.40-2.00), and curvature ratios (CRBf between -0.05-0.50) to optimize aberration correction while maintaining a compact telephoto configuration with 8 or fewer lenses.
Solution Approach 2:
The patent uses composite material principles by combining lenses with different refractive properties in specific configurations. The optical system comprises a front group with a positive refractive power lens and a rear group with a negative refractive power lens, where each lens is made from materials with specifically controlled refractive indices and dispersion characteristics to achieve both compactness and high aberration correction performance.
2Length of moving object
If the power arrangement is strengthened to achieve downsizing, then the optical system becomes more compact, but the complexity of correcting various aberrations increases
Solution Approach 1:
The patent reduces device complexity by optimizing key parameters within specific ranges. It controls the number of lenses to 8 or fewer, sets the refractive index ratio NdLA/NdLB between 0.90-1.05, Abbe number ratio νdLA/νdLB between 0.40-2.00, and curvature ratio CRBf between -0.05-0.50, thereby achieving compact length while managing aberration correction complexity through parameter optimization rather than increasing lens count.
Solution Approach 2:
The patent segments the optical system into a front group containing a positive refractive power lens and a rear group containing a negative refractive power lens, with specific segmentation of lens elements (lens A closest to object side, lens B closest to image side). This segmentation allows independent optimization of each group's aberration correction while maintaining overall system compactness.
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 a compact, high-performance optical system that effectively corrects aberrations, reduces size and weight, and lowers costs, while maintaining high imaging quality.
Implementation Method 1
an optical system including a lens A having positive refractive power and being closest to the object side in the front group and a lens B having negative refractive power and being closest to an image side in the rear group
Data Source
AI summary
In order to solve the above problem, an optical system according to the present invention includes a front group, a diaphragm, and a rear group in order from an object side, in which the optical system includes a lens A having positive refractive power and being closest to the object side in the front group and a lens B having negative refractive power and being closest to an image side in the rear group, an object-side surface of the lens B has a concave surface with respect to the object side, a number of lenses having refractive power and included in the front group and the rear group is eight or less in total, and the optical system satisfies a predetermined condition.