Optical Lens Error Map Averaging After Surfacing Defect Removal

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Solution Overview

Problem

Current optical lens manufacturing processes struggle to consistently meet optical power tolerances across different zones of a lens, leading to deviations that cannot be effectively compensated by existing manual or automated statistical analyses.

Innovation Solution

A system and method for determining the machining process signature by analyzing error maps from multiple optical lenses, identifying and removing surfacing defects, and averaging updated error maps to establish a signature that can be used to adapt the manufacturing process for subsequent lenses, ensuring closer alignment with target optical parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If manual or automated statistical analysis is performed to determine average deviation, then the manufacturing process can be compensated at a single point, but it cannot handle different deviations according to different zones of the lens

Engineering Contradiction:
Improveability to handle different deviations in different zonesVSAvoidoptical power tolerances
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent divides the lens into multiple zones and creates separate error maps for each zone rather than treating the lens as a single entity. This segmentation allows the system to identify and compensate for deviations specific to each zone, resolving the contradiction between adaptability to different zones and manufacturing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by generating zone-specific compensation values based on error maps that capture local deviations. Each zone receives tailored compensation rather than a uniform single-point compensation, enabling the system to address unique characteristics of different lens regions while maintaining overall manufacturing precision.

Inventive Principle:
Principle #3Local quality

2Reliability

If error maps are averaged directly without removing surfacing defects, then the calculation is simpler, but the process signature is contaminated by anomalies and does not represent the true machining process

Engineering Contradiction:
Improveaccuracy of process signatureVSAvoidcomplexity of error map processing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by detecting and removing surfacing defects from error maps before averaging them to generate the process signature. This preprocessing step ensures that the final signature reflects only the true machining process characteristics without contamination from anomalies, thereby improving reliability while managing complexity through systematic defect removal.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If single-point compensation is applied in the Lens Design System, then the implementation is straightforward, but it fails to account for zone-specific deviations across the lens surface

Engineering Contradiction:
Improvesimplicity of compensation implementationVSAvoidzone-specific optical power accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent transitions from single-point compensation to a multi-dimensional approach by creating a map of compensation values across the entire lens surface. This dimensional expansion allows the system to account for zone-specific deviations while maintaining ease of manufacture through automated calculation and integration into the existing Lens Design System.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4385716A1Determination of an optical lens machining process signature
Publication Date: 2024.06.19 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)
  • EP4385716A1 patent drawingFigure 1~3
  • EP4385716A1 patent drawingFigure 4
  • EP4385716A1 patent drawing

AI summary

System for determining a signature of an optical lens machining process, the system being configured to: - determine: • at least two error maps associated respectively with at least two optical lenses machined using the optical lens machining process, • at least one surfacing defect in a first of the at least two error maps, • at least one surfacing defect in a second of the at least two error maps, - remove from the first of the at least two error maps the at least one surfacing defect in the first of the at least two error maps to obtain a first updated error map, - remove from the second of the at least two error maps the at least one surfacing defect in the second of the at least two error maps to obtain a second updated error map, - determine the signature of the optical lens machining process by averaging at least the first updated error map and the second updated error map.