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US 6,206,673 B1Granted
Plastic lens and plastic lens manufacturing system
AssigneeOphthalmic Research Group International, Inc.
InventorsN. Thornton Lipscomb, Omar M. Buazza
Life of this patent
Estimating the term…
Abstract
System for making a plastic lens. Mold members are spaced apart to define a mold cavity. Ultraviolet light is directed against at least one of the mold members to cure a composition and form a substantially clear eyeglass lens in less than one hour.
Claims33
A system for making a plastic eyeglass lens, comprising:
- (i) a lens forming apparatus, comprising:
- a first mold member having an inner casting face and an outer non-casting face;
- a second mold member having an inner casting face and an outer non-casting face, the second mold member being spaced apart from the first mold member during use such that the casting faces of the first mold member and the second mold member define a mold cavity, at least a portion of the mold cavity having a thickness of at least about 15 mm;
- a light generator for generating and directing ultraviolet light against at least one of the non-casting faces of the first and second mold members during use;
- (ii) a lens forming composition adapted to cure to form a substantially clear eyeglass lens when cured by exposure to ultraviolet light in the mold cavity, the lens forming composition comprising a photoinitiator and at least one polyethylenic-functional monomer containing at least two ethylenically unsaturated groups selected from acrylyl and methacrylyl, wherein less than about 30% by weight of the composition comprises an aromatic containing bis(allyl carbonate)-functional monomer, and wherein the lens forming composition is curable by exposure to ultraviolet light to form a substantially clear eyeglass lens in a time period of less than one hour;
- and wherein the system is adapted to cure the lens forming composition to form the substantially clear eyeglass lens with a thickness greater than about 1.5 mm in a time d of less than one hour.
3 more elements
Dependencies are inferred from the claim text.