Iris Lens Assembly Aberration Correction via Segmented Optics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current iris lens assemblies for portable electronic devices face challenges in achieving a compact structure, high image quality, and high recognition accuracy, particularly in biometric applications, due to the need for higher brightness and resolution.
Innovation Solution
The iris lens assembly consists of three lenses with specific refractive powers and surface types, arranged along an optical axis, including a first lens with positive refractive power, a second lens with negative refractive power, and a third lens with positive or negative refractive power, along with an aperture diaphragm and an infrared filter, optimized to achieve compactness, miniaturization, improved brightness, and enhanced image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of lenses is increased to improve image quality, then image quality is improved, but device complexity increases
Solution Approach 1:
The lens assembly is segmented into three distinct lens elements with specific refractive powers (first lens: positive, second lens: negative, third lens: positive or negative). Each lens element performs specific optical functions, allowing the system to achieve high image quality while maintaining manageable complexity through functional segmentation.
Solution Approach 2:
The patent applies parameter changes by specifying precise refractive power combinations and surface curvature relationships (e.g., radius of curvature ratios between lens surfaces) to optimize image quality. The third lens can have either positive or negative refractive power depending on specific design requirements, demonstrating flexible parameter adjustment to balance performance and complexity.
2Volume of moving object
If the lens assembly is miniaturized to reduce device size, then device size is reduced, but image quality deteriorates
Solution Approach 1:
The lens assembly employs a nested arrangement where the aperture diaphragm is positioned between the first and second lenses, and the infrared filter is placed after the third lens. This nested configuration allows multiple functional elements to be compactly integrated without significantly increasing the overall assembly volume, maintaining miniaturization while preserving image quality.
Solution Approach 2:
The patent optimizes the spatial arrangement of lens elements along the optical axis with specific distance ratios (e.g., distance from first lens to aperture diaphragm relative to aperture diaphragm to second lens distance). By carefully controlling axial spacing and surface curvature ratios, the design achieves compact dimensions while maintaining proper optical path lengths for high-quality imaging.
3Illumination intensity
If the aperture diaphragm is added to control light, then brightness is improved, but device complexity increases
Solution Approach 1:
The aperture diaphragm serves multiple functions: it controls the amount of light reaching the image plane (brightness control), defines the field of view, and helps reduce aberrations. By integrating this single component into the lens assembly, the patent achieves brightness improvement while minimizing the increase in overall complexity through multi-functionality.
4Measurement precision
If the infrared filter is added to improve recognition accuracy, then recognition accuracy is improved, but device complexity increases
Solution Approach 1:
The infrared filter extracts and blocks infrared wavelengths from the optical spectrum, allowing only visible light to reach the image sensor. This extraction of unwanted wavelength ranges improves iris recognition accuracy by preventing infrared interference, while the filter's placement after the third lens integrates it efficiently into the existing optical path with minimal additional 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
This configuration effectively corrects aberrations, improves recognition accuracy, and enhances image resolution, making the iris lens assembly more suitable for portable electronic devices and biometric applications.
Implementation Method 1
The first lens L1 has a positive refractive power, an object side surface S1 of the first lens L1 may be a convex surface and an image side surface S2 of the first lens L1 may be a concave surface
Implementation Method 2
The second lens L2 has a negative refractive power
Implementation Method 3
The third lens L3 has a positive refractive power or a negative refractive power
Implementation Method 4
The filter L4 is an infrared (IR) filter and a bandpass wave band of the filter L4 ranges from 750 nm to 900 nm
Data Source
AI summary
The present disclosure discloses an iris lens assembly. The iris lens assembly comprises sequentially a first lens, a second lens, a third lens and a filter from an object side to an image plane along an optical axis. An aperture diaphragm is arranged between the first lens and the second lens. The first lens has a positive refractive power, an object side surface of the first lens is a convex surface and an image side surface of the first lens is a concave surface. The second lens has a negative refractive power. The third lens has a positive refractive power or a negative refractive power. The filter is an infrared (IR) filter, and a bandpass wave band of the filter ranges from 750 nm to 900 nm.