Method for coating an ophthalmic lens within an injection molding machine
First Claim
1. A method for optically coating an injection molded thermoplastic lens that resides in an injection molding machine oriented to a horizontal parting line, comprising the steps of:
- injecting molten thermoplastic resin into an edge-gated lens-forming cavity of an injection molding machine held closed under a primary clamp force;
opening the mold at a time when the lens is rigid enough to retain its shape;
depositing an unpressurized full metered charge of liquid coating onto the center of the lens; and
co-molding the coating by ramping up the clamp force from zero to a secondary clamp force not greater than the primary clamp force to compress the liquid coating into a uniformly thick, fringe-free layer within the same lens-forming cavity volume, wherein the liquid coating thermally cures from the heat of the solidifying lens and the injection mold to form an optically transparent coating.
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Accused Products
Abstract
A method for in-mold coating of an injection molded thermoplastic lens that resides in an injection molding machine oriented to a horizontal parting line. An optical lens is initially formed by injecting molten thermoplastic resin into an edge-gated lens-forming cavity held closed under a primary clamp force. The mold is opened at a time when the lens is rigid enough to retain its shape. An unpressurized full metered charge of coating is applied onto the center of the lens. The coating is co-molded by ramping up the clamp force from zero to a secondary clamp force less than the primary clamp force to compress the coating into a uniformly thick, fringe-free layer.
17 Citations
29 Claims
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1. A method for optically coating an injection molded thermoplastic lens that resides in an injection molding machine oriented to a horizontal parting line, comprising the steps of:
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injecting molten thermoplastic resin into an edge-gated lens-forming cavity of an injection molding machine held closed under a primary clamp force; opening the mold at a time when the lens is rigid enough to retain its shape; depositing an unpressurized full metered charge of liquid coating onto the center of the lens; and co-molding the coating by ramping up the clamp force from zero to a secondary clamp force not greater than the primary clamp force to compress the liquid coating into a uniformly thick, fringe-free layer within the same lens-forming cavity volume, wherein the liquid coating thermally cures from the heat of the solidifying lens and the injection mold to form an optically transparent coating. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification