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US 4,728,469 AGranted
Method and apparatus for making a plastic lens
AssigneeSperti Drug Products, Inc.
InventorsMichael E. Danner, Nathan T. Lipscomb
Life of this patent
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AssigneeSperti Drug Products, Inc.
InventorsMichael E. Danner, Nathan T. Lipscomb
Estimating the term…
A method and apparatus for making a plastic lens and a plastic lens made thereby are provided, the method comprising the steps of disposing a lens forming material comprising a liquid monomer and a photosensitive initiator into a mold cavity defined in part between a pair of spaced apart mold members each having a lens forming surface facing the cavity and an outer opposed surface, directing rays of ultraviolet light from a source thereof against the outer surface of at least one of the mold members so as to pass therethrough to act on the lens forming material in the cavity to produce the lens therefrom, and forming the outer surface of the one mold member with structure to cause the ultraviolet light directed thereagainst to be substantially evenly distributed throughout the lens forming material in the cavity in order to tend to prevent optical distortions in the lens being formed therefrom.
In a method for making a plastic lens comprising the steps of disposing a lens forming material comprising a liquid monomer and a photosensitive initiator into a mold cavity defined in part between a pair of spaced apart mold members each having a lens forming surface means facing said cavity and an outer opposed surface means, and then directing rays of ultraviolet light from a source thereof against said outer surface means of at least one of said mold members so as to pass therethough to act on said lens forming material in said cavity to produce said lens therefrom, the improvement comprising the step of frosting said outer surface means of said one mold member to cause said ultraviolet light directed thereagainst to be substantially evenly distributed throughout said lens forming material in said cavity in order to tend to prevent optical distortions in said lens being formed therefrom.
In an apparatus for making a plastic lens from a lens forming material that comprises a liquid monomer and a photosensitive initiator, said apparatus comprising a mold cavity defined in part as a pair of spaced apart mold members defining part of a mold cavity therebetween, each mold member having a lens forming surface means facing said cavity and an outer opposed surface means, and means for directing rays of ultraviolet light against said outer surface means of at least one of said mold members so as to pass therethrough to act on said lens forming material in said cavity to produce said lens therefrom, the improvement wherein said outer surface means of said one mold member has been frosted to cause said ultraviolet light directed thereagainst to be substantially evenly distributed throughout said lens forming material in said cavity in order to tend to prevent optical distortions in said lens being formed therefrom.
Dependencies are inferred from the claim text.