Fringe Deflectometry for Full-Surface Lens Characterization
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Solution Overview
Problem
Existing methods for characterizing optical elements to slow down myopia progression are complex, costly, and time-consuming, covering only reduced areas and lacking reliability and economy for duplication.
Innovation Solution
A method using fringe deflectometry with pixel sizes of 0.05 mm×0.05 mm or less to obtain a two-dimensional representation of local optical power, combined with characterizing optical elements on a lens element holder to determine various optical properties, including sphere, cylinder, asphericity, and density, using structured or random networks of optical elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional measurement methods are used to characterize optical elements, then measurement reliability is improved, but measurement time increases and productivity decreases
Solution Approach 1:
The patent replaces conventional mechanical/optical measurement systems with a digital imaging-based deflectometry system. By projecting fringe patterns and capturing images with a camera, the system measures optical element characteristics without physical contact or complex optical paths, achieving both high reliability and fast measurement speeds.
Solution Approach 2:
The patent creates a digital copy of the optical element's surface topology through fringe pattern distortion analysis. The measured surface data is used to calculate optical power distribution, replacing the need for direct optical power measurement with a computational model based on surface geometry copying.
2Measurement precision
If conventional measurement methods are used to characterize optical elements, then measurement accuracy is improved, but measurement area is reduced and coverage is limited
Solution Approach 1:
The patent divides the optical element surface into multiple measurement zones by projecting different fringe patterns across different areas. Each fringe pattern captures local surface information, and the results are synthesized to provide complete full-surface characterization, maintaining high precision across the entire lens area.
Solution Approach 2:
The patent transitions from point-by-point or small-area measurements to full-surface mapping by utilizing the two-dimensional fringe pattern projection. This allows simultaneous measurement of multiple surface points across the entire optical element, expanding coverage from limited areas to complete surface characterization.
3Reliability
If conventional measurement methods are used to characterize optical elements, then measurement thoroughness is improved, but cost increases and economy decreases
Solution Approach 1:
The patent enables the measurement system to characterize its own optical elements using standard, readily available components (camera, projector, computer). The system processes images through algorithms to extract surface and optical power information, eliminating the need for specialized expensive measurement equipment while maintaining thorough characterization.
Solution Approach 2:
The patent replaces expensive, specialized measurement equipment with inexpensive standard components. The fringe projection and image capture system uses off-the-shelf cameras and projectors, making the measurement process economical and accessible for routine quality control in manufacturing.
4Measurement precision
If existing measurement methods are used, then local area characterization is improved, but full surface characterization capability is reduced
Solution Approach 1:
The patent creates a universal measurement system that can characterize both local areas and full surfaces of optical elements. The same fringe deflectometry setup and algorithms provide detailed local surface information while simultaneously delivering complete full-surface optical power maps, making the system adaptable to various characterization needs.
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
Enables efficient, economical, and rapid characterization of optical elements, ensuring conformity and manufacturing control, thereby slowing down myopia progression effectively.
Implementation Method 1
obtaining a two-dimension representation of the local optical power of the lens element using a fringe deflectometry method
Data Source
AI summary
A method for characterizing optical elements of a lens element adapted for a person is presented, the lens element including: a holder including a refraction area having a refractive power based on a prescription for correcting an abnormal refraction of an eye of the person; and a plurality of optical elements configured so that at least one of slow down, retard or prevent a progress of the abnormal refraction of the eye of the person. A two-dimensional representation of the local optical power of the lens element is obtained using a fringe deflectometry method and the images used for the fringe deflectometry method consist of pixels smaller than or equal to 0.05 mm×0.05 mm.