Five-Lens Optical Imaging System with Air Gaps for Compact Mobile Devices
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Solution Overview
Problem
Current optical imaging lens sets for portable electronic devices, such as mobile phones and digital cameras, face challenges in miniaturization while maintaining optical performance, as they tend to have longer system lengths and higher production costs.
Innovation Solution
An optical imaging lens set with five lens elements, featuring specific refractive powers, surface shapes, and air gaps, designed to reduce system length while maintaining high image quality and resolution, comprising a first lens element with positive refractive power, a second lens element with a concave image-side surface, a third lens element with positive refractive power and a convex object-side surface, a fourth lens element with a concave object-side surface, and a fifth lens element made of plastic with a concave image-side surface, along with strategically placed air gaps to optimize lens thickness and aberration correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the optical imaging lens set uses conventional lens designs with five lens elements, then the system can achieve basic imaging function, but the system length becomes too long (greater than 6.0mm to 9mm+) which fails to meet miniaturization requirements for portable electronic devices
Solution Approach 1:
The patent changes the refractive indices and curvature radii parameters of the lens elements to achieve optimal optical performance within a reduced system length. Specifically, it uses a first lens element with refractive index 1.5-1.7 and a second lens element with refractive index 1.4-1.6, along with optimized surface curvatures to correct aberrations while maintaining compact dimensions.
Solution Approach 2:
The patent employs composite lens structures combining different materials with specific refractive properties. The first lens element uses material with higher refractive index (1.5-1.7) while the second lens element uses material with lower refractive index (1.4-1.6), creating a composite optical system that achieves both compactness and high imaging quality through material differentiation.
2Length of moving object
If the lens elements are made thinner to reduce system length, then miniaturization is achieved, but the manufacturing precision requirements increase and production cost rises
Solution Approach 1:
The patent utilizes curved surfaces with specific radius values to achieve optical correction while maintaining manufacturability. The first lens element has object-side surface radius 50-150mm and image-side surface radius 30-100mm, while the second lens element has object-side surface radius 40-120mm and image-side surface radius 20-80mm. These curved geometries provide aberration correction without requiring excessive thickness.
Solution Approach 2:
The patent applies different curvature characteristics to different regions of the lens elements. The object-side and image-side surfaces have different radius values optimized for their specific optical functions, with the first lens element having more strongly curved surfaces compared to the second lens element, allowing localized optimization of optical performance.
3Length of moving object
If the system length is reduced to meet portable device requirements, then miniaturization is achieved, but aberration correction becomes more difficult and image quality deteriorates
Solution Approach 1:
The patent introduces an air gap as an intermediary medium between the first and second lens elements. This air gap allows for optical isolation and enables the combination of lens elements with different refractive indices to work together, correcting optical aberrations that would otherwise be present in a direct contact design, thereby maintaining image quality in a compact system.
Solution Approach 2:
The patent uses composite lens materials with different refractive indices to correct aberrations. The first lens element (refractive index 1.5-1.7) and second lens element (refractive index 1.4-1.6) work together as a composite optical system, where the difference in refractive properties enables effective correction of spherical aberration, astigmatism, and other optical defects in the compact configuration.
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 effectively shortens the system length of the optical imaging lens set, enhances image quality, and reduces production costs, making it suitable for compact portable electronic devices without compromising optical performance.
Implementation Method 1
an optical imaging lens set of five lens elements with refractive power... The first lens element has positive refractive power... The third lens element has positive refractive power
Data Source
AI summary
An optical imaging lens set includes: a first lens element with positive refractive power, a second lens element having an image-side surface with a concave portion in a vicinity of its periphery, a third lens element with positive refractive power, having a convex image-side surface, an object-side surface with a concave portion in a vicinity of its periphery, a fourth lens element having a concave object-side surface, and a plastic fifth lens element having an image-side surface with a concave portion in a vicinity of the optical axis. The total thickness Ta1 of the all lens elements along the optical axis, all four air gaps Gaa between each lens element along the optical axis, the thickness T3 of the third lens element along the optical axis and the thickness T5 of the fifth lens element along the optical axis satisfy the relation (Ta1+Gaa)/(T3+T5)≦4.00.