Custom Ophthalmic Lens Precursor via Voxel-Based Lithography
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Solution Overview
Problem
Current methods for manufacturing ophthalmic lenses, such as cast molding, are limited in producing custom lenses tailored to specific patients or applications, as they require high-volume production and are not suitable for creating lenses with unique shapes or sizes.
Innovation Solution
The method involves forming an ophthalmic Lens Precursor using a substrate with an optical quality area, where actinic radiation is transmitted to polymerize a reactive mixture, allowing for the creation of customized surfaces with varying moduli and shapes through voxel-based lithography, enabling the production of lenses with specific optical and structural features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cast molding is used to manufacture ophthalmic lenses, then high-volume production efficiency is achieved, but the ability to produce custom lenses for specific patients is lost
Solution Approach 1:
The patent replaces traditional mechanical injection molding with a photopolymerization-based fabrication system. A digital light processing apparatus uses projected patterns of light to selectively cure resin material, building custom ophthalmic lenses layer by layer. This substitution of mechanical processes with optical-chemical processes enables customization while maintaining production efficiency.
Solution Approach 2:
The invention changes the fundamental parameters of the manufacturing process by using variable intensity light exposure, different resin formulations, and adjustable layer thicknesses. These parameter variations allow the same apparatus to produce lenses with different optical prescriptions, materials, and geometries, achieving both productivity and adaptability.
2Manufacturing precision
If injection molding techniques are used, then consistent lens quality is achieved, but the ability to create unique lens shapes and sizes is limited
Solution Approach 1:
The patent segments the lens fabrication process into discrete layers that are cured sequentially through photopolymerization. Each layer can be independently controlled and optimized, allowing precise creation of complex free-form surfaces while maintaining overall lens quality consistency through repeatable layer-by-layer construction.
Solution Approach 2:
The invention transitions from traditional two-dimensional mold-based shaping to three-dimensional additive fabrication. By building lenses in the third dimension through stacked cured layers, the system can create complex free-form surfaces, aspheric zones, and customized geometries that are impossible with conventional molding techniques.
3Adaptability or versatility
If lathing or stereo lithography is used to create custom lenses, then customization capability is improved, but production time increases significantly
Solution Approach 1:
The patent employs periodic pulsed light exposure to cure resin layers in rapid succession. Each layer is exposed for a brief, optimized duration, and multiple layers can be processed in sequence or parallel, significantly reducing total production time compared to continuous lathing or traditional stereo lithography while maintaining customization capability.
Solution Approach 2:
The invention performs preliminary digital modeling and light pattern generation before physical fabrication begins. The entire lens design, including optical zones, aspheric surfaces, and geometric parameters, is pre-calculated and converted into projection patterns, enabling rapid fabrication without time-consuming manual adjustments during the manufacturing process.
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 enables the fabrication of customized ophthalmic lenses with precise optical and structural properties, overcoming the limitations of traditional methods by allowing for the creation of lenses with unique shapes and sizes, improving fit and functionality for individual patients or specific applications.
Implementation Method 1
transmitting sufficient actinic radiation through the substrate to polymerize a portion of the volume of reactive mixture
Implementation Method 2
The radiation absorbing component can absorb sufficient radiation along a vector of radiation transmittance to ceases polymerization in the direction of the vector
Data Source
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AI summary
Methods for forming an ophthalmic lens precursor from a reactive mixture, on a substrate with an arcuate optical quality surface via a source of actinic radiation controllable to cure a definable portion of a volume of the reactive mixture, with at least a portion of one surface free-formed.