Voxel-Based Lithography for Custom Ophthalmic Lens Precursors

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Solution Overview

Problem

Current methods for manufacturing ophthalmic lenses, such as cast molding, struggle to produce customized lenses tailored to specific patients or applications, as they are limited by the nature of injection molding processes and equipment, which are not conducive to forming custom shapes or sizes effectively.

Innovation Solution

A Voxel-based lithographic apparatus is used to create a Lens Precursor by exposing a Reactive Mixture to actinic radiation, allowing for controlled curing and shaping of ophthalmic lenses with customizable optical and non-optical characteristics, including the use of a digital micromirror device for precise light modulation and environmental controls for optimal lens formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cast molding with injection molding processes is used to manufacture ophthalmic lenses, then high volume production of standard lens sizes and powers is achieved, but customization capability for specific patient eyes is lost

Engineering Contradiction:
Improvehigh volume productionVSAvoidcustomization capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The invention segments the lens manufacturing process into two distinct stages: (1) creating a customizable lens precursor with the desired unique shape and optical properties using photolithography, and (2) molding the precursor into the final lens form. This segmentation allows customization in the precursor creation stage while maintaining efficient molding processes in the second stage, thereby resolving the contradiction between high-volume production and customization capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention performs preliminary action by creating a lens precursor that contains the unique custom shape and optical characteristics before the actual lens molding process. The precursor is formed using photolithography techniques that allow precise customization for each patient's eye, and then this pre-formed precursor is used in subsequent molding operations, enabling both customization and efficient production.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If traditional molding techniques are used, then manufacturing efficiency is maintained, but the ability to form custom shapes and sizes is limited

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidcustom shape formation
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention replaces traditional mechanical molding techniques for shape formation with photolithography methods. Instead of using mechanical molds to force the lens material into shape, the invention uses light-based photolithography to precisely define the lens precursor shape according to the patient's unique eye geometry, thereby achieving high manufacturing precision for custom shapes while maintaining overall manufacturing efficiency through automated optical processes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If custom lenses are formed using lathing or stereo lithography, then patient-specific customization is achieved, but production time increases and material limitations arise

Engineering Contradiction:
Improvepatient-specific customizationVSAvoidproduction time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The invention changes the material parameter by using a lens precursor formulation that can be precisely controlled during photolithography. This formulation allows the material to be shaped with high precision while maintaining properties suitable for final lens performance. The precursor approach enables faster production compared to traditional lathing or stereo lithography because the photolithography process can be optimized for speed while still achieving the required customization, thereby reducing production time while maintaining patient-specific capabilities.

Inventive Principle:
Principle #35Parameter changes

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

The method enables the production of high-quality, customizable ophthalmic lenses with varied optical performance and material properties, such as hydrogel or silicone hydrogel lenses, that can be tailored to individual specifications, overcoming the limitations of traditional manufacturing techniques.

Implementation Method 1

The actinic radiation is controllable to cure a portion of the Reactive Mixture in a predefined pattern

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Data Source

PatentEP2604423B1An ophthalmic lens precursor
Publication Date: 2022.10.19 JOHNSON & JOHNSON VISION CARE INC
  • EP2604423B1 patent drawingFigure 1
  • EP2604423B1 patent drawingFigure 2
  • EP2604423B1 patent drawingFigure 3

AI summary

An ophthalmic lens precursor comprising a lens precursor Form; and a fluent lens reactive mixture wherein the lens precursor form is a solid component having a first optical surface and a second surface defined by the operation of a voxel-based lithographic system, and wherein the fluent lens reactive mixture is adhered to the second surface of the lens precursor form.