Sub-surface referencing element for ophthalmic lens positioning

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Solution Overview

Problem

Inaccurate positioning of surfaces during the manufacturing of ophthalmic lenses can lead to optical errors due to the obstruction of engraved markings by protective tapes, making it difficult to determine the correct alignment of the semi-finished lens during the blocking process.

Innovation Solution

Incorporating a sub-surface referencing element between the optical faces of the lens, which is visible even when one face is covered with protective tape, allowing for accurate determination of the reference system and positioning, and using specific lighting conditions to enhance visibility of micro-markings that define the reference system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If protective tape is placed on the finished face prior to blocking, then the finished face is protected from damage, but the engraved markings become obscured and positioning accuracy deteriorates

Engineering Contradiction:
Improveprotection of finished faceVSAvoidpositioning accuracy
Core Design Contradiction:
StrengthVSMeasurement precision

Solution Approach 1:

A sub-surface referencing element is introduced as an intermediary reference system between the finished face and the blocking reference. This element can be viewed through the protective tape without requiring direct access to the engraved markings, thereby maintaining both protection and positioning accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The reference system is moved from the surface level (engraved markings on the finished face) to a sub-surface level. This dimensional transition allows the reference element to be accessed through the protective tape, resolving the conflict between protection and visibility.

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

2Strength

If protective tape is placed on the finished face, then the finished face is protected, but the ability to evaluate lens position after blocking deteriorates

Engineering Contradiction:
Improveprotection of finished faceVSAvoidevaluation of lens position
Core Design Contradiction:
StrengthVSDifficulty of detecting and measuring

Solution Approach 1:

The sub-surface referencing element serves as a mediator that allows evaluation of lens positioning without requiring direct visualization of the engraved markings. The element can be observed through the protective tape, maintaining evaluation capability while preserving face protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If engraved markings are used on the finished face, then the reference system is defined, but the markings become difficult to view when protective tape is applied

Engineering Contradiction:
Improvedefinition of reference systemVSAvoidvisibility of markings
Core Design Contradiction:
Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

The reference system is relocated from the surface dimension to a sub-surface dimension. This allows the reference element to be manufactured with the same ease as surface markings while gaining the advantage of being visible through protective tape due to its depth position.

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

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

This method increases the accuracy of lens positioning, reduces the risk of optical errors, and allows for easier evaluation of the lens position, thereby improving the overall quality of the manufactured ophthalmic lenses.

Implementation Method 1

the sub-surface referencing element can easily be visualized trough one of the first or second faces of the optical lens member

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2962155B1Optical lens member comprising a sub-surface referencing element
Publication Date: 2022.04.06 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)
  • EP2962155B1 patent drawingFigure 1~2
  • EP2962155B1 patent drawingFigure 3~4
  • EP2962155B1 patent drawingFigure 5A~5B

AI summary

An optical lens member comprising first and second faces connected by an external periphery surface, the optical lens member further comprises a reference system identified by at least one sub-surface referencing element located between the first and second optical faces wherein the first face comprises a first optical surface having a surface design associated with the reference system.