Optic Quality Control via Power Profile Offset Minimization
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Solution Overview
Problem
Complex power profiles in manufactured optical devices, such as contact lenses, pose challenges for quality control due to increased variation and multiple aberration modes, requiring more sophisticated testing methods that can handle high-speed manufacturing and real-time analysis.
Innovation Solution
A method for assessing the similarity between measured and nominal power or surface profiles using parametric descriptors, involving region selection, offset determination, scaling, and asphericity correction to minimize statistical quantifiers, allowing for real-time quality control on high-speed manufacturing lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If simple testing procedures (focimeter verification) are used for manufactured optic devices, then testing speed and simplicity are improved, but measurement precision and reliability are insufficient for complex power profiles
Solution Approach 1:
The system transforms the power profile measurement into a different parameter space by calculating spherical aberration coefficients (C40, C42, C44) and other Zernike coefficients. This parameter transformation allows complex power profiles to be characterized by a limited set of coefficients that can be quickly compared against nominal values, maintaining high testing speed while achieving precise measurement of complex profiles.
Solution Approach 2:
The patent replaces traditional mechanical focimeter verification with an optical measurement system that uses wavefront sensing and computational analysis. This substitution enables the system to handle complex power profiles that cannot be adequately measured by simple focal point verification, while maintaining high throughput through automated image processing and coefficient calculation.
2Productivity
If offline sampling testing is performed on manufactured optic devices, then manufacturing speed is maintained, but quality control reliability deteriorates due to delayed detection
Solution Approach 1:
The system performs preliminary characterization of the power profile during or immediately after the manufacturing process, calculating spherical aberration coefficients and comparing them to nominal values before the devices leave the production line. This preliminary action enables real-time quality control decisions, ensuring consistent quality while maintaining manufacturing throughput by preventing defective devices from entering inventory.
Solution Approach 2:
The system implements a feedback mechanism where measured power profile coefficients are continuously compared against nominal values and acceptance criteria. This feedback loop enables real-time quality control decisions, allowing the system to maintain high reliability by immediately identifying and flagging defective devices while preserving manufacturing speed through automated decision-making.
3Measurement precision
If detailed power profile measurements are taken on all devices, then measurement precision is improved, but testing time and device complexity increase
Solution Approach 1:
The system extracts only the essential characteristics of the power profile by calculating specific Zernike coefficients (spherical aberration coefficients C40, C42, C44) and other key parameters. This extraction approach captures the critical features of complex power profiles without requiring complete characterization of every detail, thereby achieving sufficient measurement precision while minimizing testing time and computational complexity.
Solution Approach 2:
The patent applies partial action by measuring and analyzing only the most critical aspects of the power profile (spherical aberration coefficients and selected Zernike coefficients) rather than performing exhaustive measurements of all profile characteristics. This partial characterization provides sufficient quality control for complex power profiles while significantly reducing measurement and processing time compared to complete profile analysis.
Data Source
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AI summary
A method for assessing the similarity between a power profile of a manufactured optic device and a nominal power profile upon which the power profile of the manufactured optic device is based. The method comprises measuring the power profile of manufactured optic device, identifying a region of interest from the measured power profile of manufactured optic device, and applying an offset to the measured power profile to substantially minimize a statistical quantifier for quantifying the similarity between the nominal power profile and the offset measured power profile. The method further comprises comparing the offset and the statistical quantifier to predefined quality control metrics, determining whether the measured power profile meets the predefined quality control metrics based, at least in part on the comparison. In exemplary embodiments, the method may further comprise determining whether to associate the manufactured optic device with another nominal power profile, if the measured power profile does not meet the predefined quality control metrics.