Removable Lens Support for Free-Floating Ophthalmic Lens Inspection

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Solution Overview

Problem

Existing optical inspection systems for contact lenses face challenges in distinguishing lens defects from imperfections on the test trough surface, due to dirt, air bubbles, or scratches, which are difficult to avoid in industrial settings.

Innovation Solution

A cuvette design where the lens support is removable, allowing the contact lens to float freely during inspection, eliminating the impact of surface imperfections and ensuring that only the lens surface is in the field of focus, using a removable iris diaphragm or wire-type support that is mechanically, magnetically, or foldably detached.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lens support is used to hold the contact lens during inspection, then the lens can be positioned and supported, but surface imperfections (dirt, air bubbles, scratches) on the support surface can interfere with optical inspection

Engineering Contradiction:
Improvelens positioning and supportVSAvoidsurface imperfections interfering with inspection
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent removes the lens support entirely from the inspection field of view. The support is extracted or taken out of the optical path, allowing inspection of the freely floating lens without any support surface interfering. This directly resolves the contradiction by eliminating the source of surface imperfections while the lens remains positionable in the liquid medium.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If a fixed lens support is used, then inspection can be performed, but the support surface imperfections cannot be distinguished from lens defects

Engineering Contradiction:
Improvedefect identification accuracyVSAvoiddistinguishing lens defects from support defects
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The lens support is extracted from the inspection field, eliminating the confounding factor of support surface imperfections. This allows the optical inspection system to measure and detect only lens defects without the complexity of distinguishing them from support defects, directly improving measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If a removable lens support is used, then surface imperfections are eliminated during inspection, but the device complexity increases

Engineering Contradiction:
Improveelimination of surface imperfectionsVSAvoidremovable support mechanism
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The lens support is extracted from the optical path during inspection. The support can be removed or retracted so that only the freely floating lens remains in the field of view, eliminating surface imperfections while keeping the removal mechanism relatively simple.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The lens support is made dynamic rather than static. It can be positioned to support the lens during handling and then removed or retracted during inspection. This dynamic behavior allows the system to adapt to different operational phases, eliminating surface imperfections during inspection while maintaining support functionality during lens placement.

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If the lens support surface is in the field of focus, then the lens can be supported, but optical quality is degraded by dirt, air bubbles, or scratches

Engineering Contradiction:
Improvelens support functionVSAvoidoptical quality of inspection
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The lens support is extracted from the field of focus during optical inspection. By removing the support from the optical path or positioning it outside the focal plane, the system achieves high optical quality for inspection while the support function remains available when needed for lens handling.

Inventive Principle:
Principle #2Taking out (Extraction)

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 approach ensures high-quality optical inspection by keeping the lens surface isolated from potential distortions, allowing precise imaging and defect identification with minimal disturbance, maintaining inspection accuracy and clarity.

Implementation Method 1

The wire-type support member is disposed to interact with the lens through surface tension effects of the liquid to immobilize the lens on the surface of the liquid whereon the lens is floated just out of contact with the support member.

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 2

contact lenses typically have a density at least slightly higher than water, therefore once completely immersed they are slowly sinking to the bottom of a water-filled cuvette

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP1938074B1Cuvette for optical inspection of free floating ophthalmic lenses
Publication Date: 2012.04.18 NOVARTIS AG
  • EP1938074B1 patent drawingFigure 1
  • EP1938074B1 patent drawingFigure 2
  • EP1938074B1 patent drawingFigure 3

AI summary

The invention relates to a cuvette for an ophthalmic lens, for testing the latter using an optical inspection system, said cuvette comprising a hollow space (11) to be filled with a liquid and has an axis (12) coinciding, in the test position of the cuvette, with the optical axis of an inspection system and, between a first viewing glass (13) at the top and a second viewing glass (15) at the bottom, a removable lens support (16) is arranged in the lower area of the hollow space (11), so as to allow a free floating inspection of the lens (14) at a defined inspection position when the lens support (16) is removed.