Ophthalmic Lens Insert Positioning via Pre-formed Recess
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Solution Overview
Problem
Conventional processes for manufacturing ophthalmic lenses with inserts face challenges in precise positioning, mechanical stress, and air bubble formation, leading to potential breakage and optical imperfections during machining and polishing.
Innovation Solution
A process involving a recess in the lens element to precisely house the insert, reducing the amount of moulding material and allowing for precise positioning, with adhesive bonding to prevent movement and bubble formation, using compatible materials for reduced shrinkage and stress, and employing 3D printing or moulding for shaping the lens faces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional moulding processes are used with a pad to receive the waveguide, then the waveguide can be integrated into the lens, but the process requires very strict parallelism and alignment tolerances and high positional precision for adhesive bonding
Solution Approach 1:
The patent extracts the waveguide positioning function from the complex mould system by creating a dedicated recess in the lens blank that precisely houses the waveguide. This separates the positioning function from the mould's alignment requirements, eliminating the need for strict parallelism and alignment tolerances in the mould design while maintaining high positioning precision.
Solution Approach 2:
The recess is pre-formed in the lens blank before the waveguide is inserted and bonded. This preliminary action establishes the precise position and orientation of the waveguide beforehand, eliminating the need for high-precision adhesive bonding operations and complex mould alignment during the actual assembly process.
2Reliability
If conventional moulding processes are used with substantial amounts of moulding material, then the lens can be fully formed, but mechanical stress effects create imperfections, delamination, and may weaken or break the insert
Solution Approach 1:
The patent extracts only the necessary amount of moulding material by forming a recess that precisely houses the waveguide. This minimizes the volume of moulding material that needs to be polymerized, thereby reducing shrinkage and mechanical stresses exerted on the waveguide, preventing delamination and breakage while still achieving complete lens formation.
Solution Approach 2:
The recess provides a localized precise fit for the waveguide, ensuring proper positioning and support exactly where needed. This local precision housing reduces stress concentration on the waveguide while allowing the surrounding lens material to be formed with standard moulding processes, balancing local integrity with overall manufacturing feasibility.
3Ease of manufacture
If a thin layer of adhesive material is used to bond the insert, then the insert can be attached to the lens, but air bubbles may form between the composite product and the insert
Solution Approach 1:
The recess is pre-formed to precisely accommodate the waveguide, establishing proper positioning and minimizing gaps before bonding occurs. This preliminary precise housing reduces the likelihood of air bubble formation during the adhesive bonding process while maintaining manufacturing simplicity.
4Manufacturing precision
If the waveguide is positioned with high precision during moulding, then the optical specifications can be met, but the process becomes complex and requires special tools
Solution Approach 1:
The recess is pre-formed in the lens blank with the precise dimensions and positioning required for optimal optical performance. This preliminary action embeds the positioning precision directly into the lens blank geometry, allowing the waveguide to be simply inserted and bonded without requiring complex positioning tools or procedures during the assembly 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 ensures precise positioning and reduced mechanical stress on the insert, minimizing the risk of breakage and optical imperfections, while allowing for flexible integration and efficient manufacturing with simpler tools, resulting in a lightweight, aesthetically pleasing, and optically accurate lens.
Implementation Method 1
adhesive bonding to prevent movement and bubble formation
Implementation Method 2
depositing a second material in liquid form on the first face of the intermediate product so as to cover at least partially the insert with this second material, by means of mould portions... and solidifying this second material
Implementation Method 3
depositing a second material in liquid form on the first face of the intermediate product so as to cover at least partially the insert with this second material, by means of mould portions, one of which 3A is frontal and the other of which 3B is lateral and peripheral
Data Source
Figure 1A~1C
Figure 2A~2C
Figure 3A~3D
AI summary
The invention relates to a process for manufacturing an ophthalmic lens element equipped with an insert (1), this ophthalmic lens element comprising a front face and a back face, comprising steps consisting in: providing a first portion or intermediate product (2, 2") made of a first material comprising a first and second frontal face (2A, 2B, 2A", 2B"), said second face forming the back or front face of said ophthalmic lens element; placing the insert (1) on said first face of said intermediate product; depositing a second material in liquid form on said first face of the intermediate product (2, 2") so as to cover at least partially said insert with said second material; and solidifying said second material in order to form an integral second portion (4) of said intermediate product. According to the invention, said first material is organic.