Ophthalmic Lens Pressing Control for Electrochromic Cell Gap Stability

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Solution Overview

Problem

Existing methods for assembling electrochromic cells using ophthalmic lenses face challenges in maintaining a consistent gap due to the weakness of microspheres in adhesive substances, which can collapse under high pressure or fail to maintain the gap under low pressure.

Innovation Solution

A method and device using springs or programmable electric motors to control the pressure applied to ophthalmic lenses, ensuring a predetermined gap is maintained by managing the pressure effort through maximum values or current intensity, with optional pressure gauges and encoders for precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high pressure is applied to the microspheres in the adhesive substance, then the gap between lenses can be maintained, but the microspheres may collapse

Engineering Contradiction:
Improvegap consistencyVSAvoidmicrosphere integrity
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent removes microspheres from the adhesive substance and replaces them with a rigid support structure consisting of a plate and adjustable micrometer screws. This extraction eliminates the weakness of microspheres while maintaining the gap-control function through a different mechanism - mechanical adjustment and rigid support rather than spherical spacers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a plate as an intermediary element between the lenses and the adjustment mechanism. This plate distributes the pressure evenly across the lens surface and provides a stable base for the micrometer screws, allowing precise gap control without directly applying point pressures that could collapse the lens structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If low pressure is applied to the microspheres, then the microspheres remain intact, but the gap between lenses is not maintained

Engineering Contradiction:
Improvemicrosphere integrityVSAvoidgap consistency
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

By removing microspheres entirely and replacing them with a rigid plate supported by micrometer screws, the invention eliminates the trade-off between microsphere integrity and gap maintenance. The new system maintains gaps through mechanical adjustment rather than relying on the compressibility of microspheres.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the static gap-maintenance function of microspheres into a dynamic adjustment system using micrometer screws. This allows the gap to be precisely controlled and adjusted during assembly, providing manufacturing precision without relying on the mechanical properties of microspheres.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If a rigid support structure is used instead of microspheres, then gap precision is improved, but the device complexity increases

Engineering Contradiction:
Improvegap controlVSAvoidassembly structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The support structure is segmented into distinct functional components: a plate for distributing pressure, multiple micrometer screws for independent adjustment at different locations, and a framework for holding the lenses. This segmentation allows each component to perform its specific function efficiently while maintaining overall simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The plate serves multiple functions simultaneously: it supports the lenses, distributes pressure evenly across the lens surface, provides a mounting surface for the micrometer screws, and maintains the structural integrity of the assembly. This multi-functionality reduces the need for additional components, offsetting the increased complexity with functional consolidation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 consistent and controlled application of pressure to form electrochromic cells with precise gap maintenance, eliminating the need for microspheres and enhancing the stability of the cavity formation process.

Implementation Method 1

applying a pressure effort on the first and second lenses by at least one spring

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4356188B1A method and device for pressing against each other two ophthalmic lenses in order to build an electrochromic cell
Publication Date: 2026.03.04 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)
  • EP4356188B1 patent drawingFigure 1~2
  • EP4356188B1 patent drawingFigure 3~4

AI summary

This device (10) for pressing against each other a first ophthalmic lens having a first face and a second ophthalmic lens having a second face in order to build an electrochromic cell comprising a cavity delimited by the first and second faces, the first and second ophthalmic lenses being superposed and an adhesive substance being applied on at least one of the first and second faces to form the cavity, comprises the first and second ophthalmic lenses and at least one spring (20) adapted to apply a pressure effort on the first and second ophthalmic lenses. It further comprises a programmable electric motor adapted to actuate said at least one spring (20) and to control said pressure effort.