Four-Lens Assembly Layout for Low F-Number Compact Imaging
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Solution Overview
Problem
Existing optical devices face challenges in achieving high-quality images and videos with low F number and small aberrations while accommodating high-pixel-count image sensors within limited mounting spaces, particularly in portable electronic devices.
Innovation Solution
A lens assembly comprising at least four lenses, including a first lens, a second lens with a concave image-side surface, a third lens, and a fourth lens, designed to satisfy specific optical parameters (Equations 1 to 4) to optimize image quality and fit within compact electronic devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple lenses are combined to achieve low F number and small aberration, then image quality is improved, but device complexity increases
Solution Approach 1:
The lens assembly is divided into multiple discrete lens elements (first lens, second lens, third lens, fourth lens) with specific focal lengths and positions. Each lens element contributes to correcting specific types of aberrations, allowing the system to achieve high image quality through the combined effect of segmented optical components rather than a single complex lens
Solution Approach 2:
The patent specifies precise parameter ranges for each lens element including focal lengths (f1, f2, f3, f4), distances between lenses (d1, d2, d3), and the ratio of total track length to image height (0.9 < TTL/IH < 1.1). By optimizing these parameters within defined ranges, the system achieves low F number and minimal aberration while controlling overall complexity
2Measurement precision
If high-pixel-count image sensors are used to achieve high-resolution images, then spatial resolution is improved, but mounting space requirements increase
Solution Approach 1:
The patent controls the total track length (TTL) relative to the image height (IH) within a specific range (0.9 < TTL/IH < 1.1), effectively optimizing the depth dimension of the optical system. This dimensional optimization allows high-pixel-count sensors to be accommodated within compact mounting spaces while maintaining high spatial resolution capabilities
Solution Approach 2:
By specifying precise parameter ranges for focal lengths, lens distances, and the TTL/IH ratio, the patent optimizes the optical system to work efficiently with high-pixel-count sensors in compact form factors, enabling high spatial resolution without proportionally increasing mounting space requirements
3Volume of moving object
If the lens assembly is compacted to fit portable devices, then device size is reduced, but optical performance deteriorates
Solution Approach 1:
The patent defines specific parameter ranges for a compact lens assembly including focal lengths (f1, f2, f3, f4), inter-lens distances (d1, d2, d3), and the critical TTL/IH ratio (0.9 < TTL/IH < 1.1). These parameter optimizations enable the system to maintain bright image capture and wide field of view while achieving a compact form factor suitable for portable devices
Solution Approach 2:
The patent allows for adjustable distances between lens elements (d1, d2, d3) that can be optimized for different operating conditions. This dynamic adjustment capability enables the compact lens assembly to maintain optimal optical performance across varying conditions while preserving a small form factor for portable device integration
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 lens assembly achieves a bright and high-resolution image capture with a wide field of view, meeting the requirements for high-pixel-count image sensors in a compact form factor.
Implementation Method 1
The lens assembly may include a first lens, a second lens having an image-side surface with a concave shape toward the image side, a third lens, and a fourth lens
Data Source
AI summary
Provided is an optical system including a lens assembly including four lenses sequentially arranged along an optical axis from an object side toward an image side, the lens assembly including a first lens, a second lens having an image-side surface concave toward the image side, a third lens, and a fourth lens, and an image sensor including an imaging plane on which an image is configured to be formed, the electronic device satisfies: IH≥2.9 mm, f/EPD≤2.3, TTL/(IH*2)<0.74, and N2≥1.66, where IH is half of a diagonal length of the image sensor, f is an effective focal length of the optical system including the lens assembly and the image sensor, EPD is an entrance pupil diameter, TTL is a distance from an object-side surface of the first lens to the imaging plane, and N2 is a refractive index of the second lens at a wavelength of 587.6 nm.