Five-Lens Optical System with Aspheric Surfaces for Low-Light Imaging
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Solution Overview
Problem
Conventional optical image capturing systems for portable electronic devices face challenges in capturing high-quality images in low-light environments due to limited light intake and difficulty in simultaneously focusing visible and infrared light effectively.
Innovation Solution
The optical image capturing system employs a five-piece optical lens configuration with aspheric surfaces and inflection points to adjust incident angles and modify optical paths, enhancing light intake and image quality, and includes a filtering component to manage visible and infrared light effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional optical system with three or four lenses is used, then the device complexity is reduced, but the light intake is limited and imaging quality in low-light environments deteriorates
Solution Approach 1:
The optical system is divided into five distinct lens elements (first lens to fifth lens), each with specific refractive power and surface characteristics. This segmentation allows each lens to contribute differently to light gathering and image formation, enabling high light intake while maintaining manageable complexity through modular design
Solution Approach 2:
The patent employs aspheric surfaces on multiple lenses (first, third, fourth, and fifth lenses have aspheric object-side or image-side surfaces). These curved surfaces optimize light path control and increase light intake efficiency, resolving the contradiction between simple structure and high performance by using sophisticated surface geometry rather than additional lens elements
2Illumination intensity
If the optical system is designed with large aperture for low-light photography, then the light intake increases, but the imaging quality and focus precision for both visible and infrared light deteriorate
Solution Approach 1:
Different lenses are assigned specific local functions: the first lens with negative refractive power and aspheric object-side surface controls incoming light; the second lens with positive refractive power focuses light; the third lens with aspheric image-side surface refines focus; the fourth and fifth lenses with aspheric surfaces correct aberrations. This localized functional assignment maintains focus precision across the large aperture
Solution Approach 2:
The patent specifies precise parameter ranges for each lens including refractive power ratios (e.g., -0.5 < f1/f < 0), aspheric surface coefficients (A4, A6, A8, A10, A12), and thickness ratios (0.3 < ETP1/TP1 < 1.5). These parameter optimizations ensure that the large aperture design maintains high focus precision for both visible and infrared light by controlling spherical and chromatic aberrations
3Manufacturing precision
If five-piece optical lens configuration with aspheric surfaces is used, then the imaging quality and light intake are improved, but the manufacturing complexity increases
Solution Approach 1:
Aspheric surfaces are implemented on the first, third, fourth, and fifth lenses to correct optical aberrations and improve image quality. While aspheric surfaces increase manufacturing complexity compared to spherical surfaces, the patent balances this by limiting the number of aspheric surfaces and providing specific coefficient ranges that can be achieved with modern manufacturing techniques
Solution Approach 2:
The patent provides specific parameter ranges for manufacturing, including aspheric coefficients (A4, A6, A8, A10, A12), refractive indices (1.5 < Nd1 < 1.9), and thickness ratios. These standardized parameter specifications enable mass production while maintaining high manufacturing precision, resolving the contradiction between complex design and ease of manufacture
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 significantly improves image quality and light intake, enabling effective capture of both visible and infrared light, thereby enhancing the performance of portable electronic devices in low-light conditions.
Implementation Method 1
combination of refractive powers, convex and concave surfaces of five-piece optical lenses to increase the quantity of incoming light
Implementation Method 2
an object-side surface and an image-side surface of the fifth lens are both aspheric... to improve imaging quality for image formation
Data Source
AI summary
An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens. At least one lens among the first to the fifth lenses has positive refractive force. The fifth lens can have negative refractive force, wherein both surfaces thereof are aspheric, and at least one surface thereof has an inflection point. The lenses in the optical image capturing system which have refractive power include the first to the fifth lenses. The optical image capturing system can increase aperture value and improve the imaging quality for use in compact cameras.