Ophthalmic Lens Spatial Curing via Actinic Radiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional cast molding techniques for ophthalmic lenses require new molds for each unique surface shape, limiting the ability to produce custom lenses with specific geometrical features without changing the manufacturing equipment or molds.
Innovation Solution
A method using existing mold halves and spatial curing with actinic radiation to create custom surface features on ophthalmic lenses, allowing for the production of lenses with varied geometries such as indentations and fenestrations without the need for complementary mold geometries, by selectively exposing the mold halves to actinic radiation according to a predetermined pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional cast molding techniques are used with fixed mold halves, then the manufacturing process is simple and reliable, but the ability to produce custom lenses with different surface shapes is limited requiring new molds for each design
Solution Approach 1:
The patent replaces the mechanical system of physical mold contact with an optical system using actinic radiation projected through a digital micromirror device. Instead of mechanically changing mold halves to create different lens surfaces, the system uses programmable light patterns to selectively cure the reactive monomer mixture, forming custom surface features without physical contact. This substitution allows infinite surface variations without manufacturing new molds.
Solution Approach 2:
The patent changes the state of the reactive monomer mixture from liquid to solid through spatially controlled polymerization. By controlling the actinic radiation exposure parameters (intensity, duration, pattern), the system creates different surface geometries by selectively curing portions of the monomer mixture. This parameter control allows the same physical mold halves to produce infinitely varied lens surface shapes.
2Adaptability or versatility
If new molds are manufactured for each unique lens surface shape, then custom lens production is enabled, but production costs and manufacturing time increase
Solution Approach 1:
The patent uses a digital micromirror device to create optical copies or projections of desired lens surface patterns directly onto the reactive monomer mixture. Instead of manufacturing physical mold copies for each design, the system projects digital patterns that are transferred to the lens material through selective curing. This digital copying approach eliminates the need for physical mold manufacturing while maintaining design fidelity.
Solution Approach 2:
The patent performs preliminary shaping of the lens surface features during the curing process itself, rather than requiring post-processing or separate molding steps. The actinic radiation patterns pre-defin e the final surface geometry by selectively polymerizing the monomer mixture in the desired configurations, eliminating the need for subsequent mechanical processing or mold changes.
3Ease of manufacture
If the mold cavity surface defines the lens surface shape, then the molding process is straightforward, but creating new surface features requires new molds
Solution Approach 1:
The patent introduces a reactive monomer mixture as an intermediary between the mold cavity and the final lens surface. Instead of the mold cavity directly defining the surface shape through contact, the monomer mixture acts as a medium that can be selectively cured by actinic radiation. This intermediary allows the mold cavity to maintain its simple geometry while the radiation-patterned curing process creates complex surface features on the resulting lens.
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 the production of ophthalmic lenses with custom surface features like rotational stability, improved tear film stability, and enhanced oxygen transmission using existing manufacturing equipment and molds, increasing flexibility and reducing production costs.
Implementation Method 1
exposing the at least one light transmissive base or front curve mold to a source of substantially uniform actinic radiation at the first wavelength according to a predetermined exposure pattern including at least one exposure portion and at least one non-exposure portion to initiate polymerization of the reactive monomer mixture within the mold at the at least one exposure portion
Data Source
AI summary
A method for forming an ophthalmic lens including providing a mold assembly including base and front curve molds each having a surface profile and defining and enclosing a cavity therebetween having a reactive monomer mixture for making the lens and a first polymerization initiator that is activated at a first wavelength. A light transmissive one of the molds is exposed to a source of substantially uniform actinic radiation at the first wavelength according to a predetermined exposure pattern including at least one exposure portion and at least one non-exposure portion to initiate polymerization of the reactive monomer mixture within the mold at said at least one exposure portion. The lens is fully cured at the exposure portions and unreacted or non-gelled portions remain within the lens adjacent to the front and base mold halves, which are extracted following removal from the mold assembly, leaving one or more predetermined geometric indentations in the front and back surfaces of the lens such that the surface profile of the lens deviates from the surface profile of the respective front and back mold halves at the locations of the geometric indentations.