Ophthalmic Lens Centering via Pattern Selection
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Solution Overview
Problem
Existing methods for centering myopia prevention lenses with randomly distributed patterns around a pattern-free area are difficult to implement, as they require knowledge of the geometrical figure, limiting their applicability to lenses with patterns along predetermined shapes.
Innovation Solution
A method using a processing unit to acquire images of the lens, detect patterns, select patterns based on their positions relative to the pattern-free area, and deduce the centering point, allowing for accurate centering of the lens regardless of pattern distribution, by determining the geometrical center and forming a polygon tangential to the selected patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the centering method requires patterns to be distributed along a predetermined geometrical figure (circle), then the centering process can be performed using known methods, but the method cannot be applied to lenses with randomly distributed patterns
Solution Approach 1:
The method segments the pattern detection process by selecting only certain patterns (e.g., those closest to the pattern-free area or patterns forming a polygon) rather than requiring all patterns to follow a predetermined geometrical distribution. This segmentation allows the centering to work with randomly distributed patterns while maintaining computational feasibility.
Solution Approach 2:
The invention uses only a subset of the detected patterns (partial action) - specifically selecting patterns that are most useful for determining the centering point - rather than requiring complete geometric information from all patterns. This partial approach enables centering to work with random distributions while keeping the process manageable.
2Adaptability or versatility
If the geometrical figure configuration is unknown at the start of centering operation, then the centering cannot be performed using existing methods, but requiring such knowledge limits the method to specific lens types
Solution Approach 1:
The method performs preliminary pattern detection and selection before determining the centering point. By first detecting all patterns and then selecting the most appropriate subset (e.g., patterns closest to the pattern-free area or patterns forming a polygon), the system prepares the necessary information in advance without requiring prior knowledge of the overall pattern distribution geometry.
Solution Approach 2:
The selection of patterns for centering is dynamic rather than static - the system adapts which patterns to use based on their actual positions and relationships to the pattern-free area, rather than requiring a fixed predetermined geometrical configuration. This dynamic selection enables the method to work with various pattern distributions.
Data Source
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AI summary
The invention relates to a method for centering an ophthalmic lens (10) comprising several distinct patterns (12) located around a pattern free area (13), said method being performed by a processing unit and comprising steps of: - acquiring at least one image of said ophthalmic lens, - processing said image to detect said patterns, - deducing therefrom a position of a centering point (AC). According to the invention, after said step of processing, only a part of said patterns are selected as a function of their positions relative to said pattern free area, and during said step of deducing, the centering point position is deduced from only the selected patterns positions.