Mould Recesses for Ophthalmic Lens Insert Positioning
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Solution Overview
Problem
Existing methods for manufacturing ophthalmic lenses with inserts, such as optical waveguides, face challenges in achieving precise positional alignment during the molding process, which is critical for optical and aesthetic specifications, and are not suitable for mass production due to the risk of waveguide breakage during machining and polishing.
Innovation Solution
A mould system with recesses on multiple portions allows for precise positioning of inserts via gravity or clamping, ensuring accurate placement and minimizing the risk of breakage, while enabling the production of lenses with complex shapes and optical modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the waveguide is adhesively bonded to the pad with high positional precision, then the optical alignment is achieved, but the manufacturing complexity and time increase significantly
Solution Approach 1:
The mould is pre-configured with recesses and positioning elements before the waveguide is inserted. The recesses are designed with precise dimensions and orientations to automatically position the waveguide in the correct location during insertion, eliminating the need for complex post-insertion alignment operations. This preliminary preparation of the mould structure ensures that when the waveguide is placed in the recess, it is automatically positioned with the required precision for optical alignment.
2Manufacturing precision
If the waveguide is positioned with high precision in the mould, then the optical specifications are met, but the risk of waveguide breakage during machining increases
Solution Approach 1:
The waveguide is positioned in the recess during the molding process before the lens material fully cures. While the material is still in a semi-pliable state, the waveguide is surrounded and protected by the soft material, which acts as a cushion during subsequent machining operations. This preliminary positioning and surrounding protection prevents the waveguide from being exposed to direct mechanical stresses that would cause breakage during later machining and polishing steps.
Solution Approach 2:
The molding material is allowed to partially cure and surround the waveguide before complete hardening occurs. This creates a cushioning effect where the semi-cured material protects the fragile waveguide from mechanical impacts during machining. The material transitions from a protective semi-pliable state to a rigid protective shell, providing beforehand cushioning that prevents waveguide breakage while maintaining precise positioning.
3Volume of moving object
If the lens is produced with minimal component volumes for light and thin design, then the aesthetic criteria are met, but the positioning tolerance for the waveguide is reduced
Solution Approach 1:
The recess is designed with non-uniform dimensions and features that are optimized for the specific local requirements of waveguide positioning. The recess includes localized positioning features such as tapered sections, asymmetric profiles, or specific geometric constraints that precisely locate the waveguide in three dimensions. This local quality approach allows the recess to provide high positioning precision in critical areas while maintaining overall compact lens dimensions, accommodating the reduced tolerance inherent in minimal-volume lens designs.
Data Source
Figure 1A~1C
Figure 2
Figure 3A~3C
AI summary
The invention relates to a mould (2) for manufacturing an ophthalmic lens or an ophthalmic lens blank called a puck (3), equipped with an insert (1), said mould comprising a first portion (2A) intended to mould the front face of the ophthalmic lens or puck, a second portion (2B) intended to mould the back face of the ophthalmic lens or puck and at least one third portion (2C) intended to mould a peripheral lateral face of the ophthalmic lens or puck. According to the invention, said mould (2) comprises at least one recess (2B1, 2B2, 2B3, 2B4) for positioning the insert (1), before and during the moulding.