Symmetrical Lens System Design for Compact Camera Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional camera lenses for wireless telephones face challenges in achieving compactness, cost-effectiveness, and high image quality due to the use of highly aspheric, free-form lenses which introduce aberrations and are costly to fabricate, while neglecting general design principles that maximize symmetry.
Innovation Solution
A symmetrical lens system design using low-order aspheric lenses, combining low and high dispersion lenses, and incorporating artificial vignetting to reduce aberrations, with a 'doublet' configuration similar to the Cooke Triplet but more compact and less expensive, utilizing UV-curable polymers and float glass substrates for improved manufacturing and reduced size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If highly aspheric, free-form lenses are used to achieve compact size and short total track, then the lens system size is reduced, but fabrication complexity and cost increase significantly
Solution Approach 1:
The patent applies low-order aspheric coefficients (2nd, 4th, 6th order) instead of high-order (10th-14th order) free-form surfaces, maintaining the necessary curvature for compact design while enabling standard fabrication processes. The aspheric terms are carefully controlled to achieve the desired optical performance without requiring complex manufacturing.
Solution Approach 2:
The patent changes the aspheric coefficient parameters from high-order (10th-14th) to low-order (2nd-6th), fundamentally altering the mathematical description of the lens surfaces. This parameter change enables the transition from free-form to controlled aspheric surfaces that can be manufactured using conventional techniques while maintaining compact form factor.
2Volume of moving object
If highly aspheric, free-form lenses are used to achieve compact size, then the lens system size is reduced, but image quality deteriorates due to increased aberrations from fabrication tolerances
Solution Approach 1:
The patent uses controlled low-order aspheric surfaces (2nd, 4th, 6th order terms) that maintain the compact form factor while providing sufficient aberration correction. The gradual curvature changes are easier to manufacture with precision and less sensitive to fabrication tolerances compared to high-order free-form surfaces.
Solution Approach 2:
The patent applies different aspheric coefficients to different zones of the lens surfaces, with lower-order terms providing overall shape control and higher local precision where needed. This localized quality approach maintains image quality while simplifying the overall manufacturing requirements.
3Manufacturing precision
If general design principles maximizing symmetry are applied, then aberrations are reduced and manufacturing is simplified, but the lens system requires more elements increasing size and material cost
Solution Approach 1:
The patent combines multiple functions into fewer lens elements. The Cooke Triplet uses three separate elements, while this patent achieves similar or better performance with two integrated lens structures, reducing overall size and material usage while maintaining aberration correction through careful optical design.
Solution Approach 2:
Each lens element in the patent performs multiple functions simultaneously - correcting spherical aberration, coma, and controlling field curvature - rather than requiring separate dedicated elements for each correction. This multi-functionality reduces the total number of elements needed while maintaining comprehensive aberration control.
4Manufacturing precision
If the Cooke Triplet configuration is used to apply general design principles, then aberrations are corrected, but the lens system becomes excessively large and material costs increase
Solution Approach 1:
The patent merges the functionality of three Cooke Triplet elements into two integrated lens structures. The outer and inner lens substrates each contain multiple optical surfaces that collectively perform the aberration correction functions of the triplet configuration, reducing material usage and overall size.
Solution Approach 2:
The patent uses a nested configuration where the inner lens substrate is positioned within the optical path defined by the outer lens substrate. This nesting allows compact arrangement of multiple optical surfaces in a reduced volume, decreasing material requirements compared to the extended Cooke Triplet 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 symmetrical lens system effectively corrects aberrations, improves fabrication tolerances, and reduces size and cost by using smaller diameter lenses, while maintaining high image quality and reducing chromatic and field curvature aberrations.
Implementation Method 1
The lens structures are formed from a UV-curable polymer
Data Source
AI summary
A lens system comprising an inner lens structure and an outer lens structure. The inner lens structure comprises an inner positive lens, a first transparent substrate and an inner negative lens. The outer lens structure comprises an outer positive lens, a second transparent substrate and an outer negative lens.