Smartphone Telephoto Lens with Folded Optical Path
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Telephoto lenses for smartphones require multiple lenses, leading to increased size and weight, which is not feasible due to the limited space available in smartphones.
Innovation Solution
An imaging lens design that incorporates a metalens and a light-turning element, folding the optical path to reduce the length of the lens, eliminating the need for multiple lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple lenses are used to achieve telephoto function, then the imaging performance is improved, but the total lens length and device weight increase significantly
Solution Approach 1:
The patent introduces a light-turning element that folds the optical path, changing the linear arrangement of lenses into a folded configuration. This allows the optical path to bend at angles (e.g., 45 degrees) rather than continuing straight, effectively reducing the axial length of the lens system while maintaining the required optical path length for telephoto functionality
Solution Approach 2:
The patent integrates multiple functional elements including a metalens, light-turning element with reflecting surfaces, and filter layer within a compact stacked arrangement. The light-turning element is positioned between the metalens and filter, creating a nested configuration that maximizes space utilization and reduces overall lens length
2Reliability
If multiple lenses are used to achieve telephoto function, then the imaging performance is improved, but the device weight increases significantly
Solution Approach 1:
The patent extracts the light-turning function from traditional multi-lens assemblies and implements it through a dedicated light-turning element with reflecting surfaces. This separation allows for more efficient use of materials and reduces the need for additional lens elements that would contribute to weight
Solution Approach 2:
The patent changes the refractive index parameter by introducing a metalens with high refractive index material, allowing for shorter focal length and reduced overall lens length. The light-turning element also utilizes specific refractive index ranges (1.5-4.5) to optimize the folded optical path while minimizing weight
3Length of moving object
If the optical path is folded using a light-turning element, then the lens length is reduced, but the device complexity increases
Solution Approach 1:
The patent segments the optical system into distinct functional modules: metalens layer, light-turning element with incident/reflecting/light-emitting surfaces, and filter layer. Each segment performs a specific function, making the complex folded optical path easier to design, manufacture, and assemble while maintaining compact length
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 provides an imaging lens with good optical performance and a small size, enabling the creation of a telephoto lens suitable for smartphones with minimal thickness.
Implementation Method 1
the light-turning element includes an incident surface, a first reflecting surface, a second reflecting surface, and a light-emitting surface in sequence from the object side to the image side along the optical axis. When entering the imaging lens, a ray is reflected at the first reflecting surface and the second reflecting surface in sequence.
Data Source
AI summary
An imaging lens including a metalens and a light-turning element in sequence from an object side to an image side along an optical axis. The light-turning element includes an incident surface, a first reflecting surface, a second reflecting surface, and a light-emitting surface in sequence from the object side to the image side along the optical axis. When entering the imaging lens, rays may be reflected at the first reflecting surface and the second reflecting surface in sequence. The first reflecting surface and the second reflecting surface are inner surfaces of the light-turning element.