Compact Five-Lens Optical Imaging System for Mobile Telescopic Function
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Solution Overview
Problem
Conventional optical imaging lens sets for portable electronic devices, such as mobile phones and cameras, are too large and fail to meet the demands for improved imaging quality with a telescopic function, as they have lens systems longer than 50 mm and F-number over 4, which are not suitable for current portable electronic products.
Innovation Solution
A compact optical imaging lens set with five lens elements, each with specific refractive powers and surface shapes, including aspherical surfaces, and strategically placed air gaps, which satisfies certain thickness and Abbe number ratios to reduce the overall length while maintaining optical performance, including ALT/T1≤3.7, ALT/G23≤4, and AAG/EFL≤0.48, to enhance telescopic function and imaging quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional optical imaging lens sets are used, then imaging quality and telescopic function are achieved, but the lens set size becomes too large (length > 50 mm)
Solution Approach 1:
The optical lens set is divided into five distinct lens elements with specific refractive powers and surface shapes. Each lens element contributes to the overall optical function while allowing compact arrangement, enabling the total length to be reduced below 50 mm while maintaining imaging quality and telescopic capability
Solution Approach 2:
The patent applies specific parameter constraints including Abbe number differences (18 ≤ υ4-υ5 ≤ 50), thickness ratios (ALT/T1 ≤ 3.7, ALT/G23 ≤ 4), and air gap relationships ((G12+T2+G23+T3+T4+G45+T5)/G34 ≤ 6.3) to optimize the optical system. These parameter changes enable compact design while preserving optical performance
2Adaptability or versatility
If conventional optical imaging lens sets are used, then telescopic function is achieved, but the F-number becomes too high (Fno > 4)
Solution Approach 1:
Different lens elements are assigned specific local properties: the first lens element has positive refractive power, the fourth lens element has negative refractive power, and the fifth lens element has a concave portion near the optical axis. This localized optimization of optical properties enables better light gathering (lower F-number) while maintaining telescopic function
Solution Approach 2:
The patent employs aspherical surfaces on the third lens element (at least one surface) and the fifth lens element (both surfaces). These curved surfaces optimize light path control and improve illumination distribution, enabling reduced F-number while preserving telescopic capability
3Reliability
If lens elements are added to improve imaging quality, then optical performance is enhanced, but device complexity increases
Solution Approach 1:
Each of the five lens elements serves multiple functions: correcting aberrations, controlling light paths, and contributing to the telescopic ratio. The first lens element (positive power) and fourth lens element (negative power) work together for focal length control, while aspherical surfaces on the third and fifth elements handle aberration correction. This multi-functionality allows achieving high optical performance with only five elements, avoiding excessive complexity
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
The solution achieves a reduced optical imaging lens system length while maintaining sufficient optical performance, improving imaging quality and facilitating the telescopic function, thus addressing the size and performance limitations of conventional lens sets.
Implementation Method 1
The optical imaging lens set of five lens elements of the present invention from an object side toward an image side in order along an optical axis has a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. Each lens element has an object-side surface facing toward an object side as well as an image-side surface facing toward an image side.
Data Source
AI summary
An optical lens assembly includes a first lens of positive refractive power, a second lens of refractive power, at least one of the object surface and the image surface being aspherical, a fourth lens of refractive power, a fifth lens of a concave object surface near its optical-axis and both the object surface and the image surface being aspherical so that the Abbe number υ4 of the fourth lens, the Abbe number υ5 of the fifth lens, an air gap G12 between the first lens and the second lens, an air gap G23 between the second lens and the third lens, an air gap G45 between the fourth lens and the fifth lens, the second thickness T2 of the second lens, the third thickness T3 of the third lens, the fourth thickness T4 of the fourth lens, and the fifth thickness T5 of the fifth lens satisfy 18≤υ4−υ5≤50 and (G12+T2+G23+T3+T4+G45+T5)/G34≤6.3.