US 4,919,850 A · Method for curing plastic lenses

Abstract

The disclosure relates to a method and apparatus for making lenses and a composition of molding material which can be utilized in the method and apparatus for molding lenses of optical quality. A monomer is used with initiators in conjunction with the molding apparatus to mold plastic lenses of optical quality without requirement for any additional polishing or grinding, except for perhaps shaping the edges. The molding material includes a composition of liquid monomer with a thermal initiator and a UV initiator each of which can be activated during the molding process. Initially, the molding forms with the liquid monomer compositions therein are heated to activate the thermal initiator and form the molding material into a gel. The gelled material is then subjected to a UV light source for completing the cure. Prepolymerized molding material can be used in some instances to avoid an intermediate step of thermal curing. Various other embodiments and apparatus are disclosed for molding plastic lens.

Claims24

Dependent claims

A method for molding and curing plastic lenses comprising the steps of:

(a) arranging a first mold form and a second mold form in a spaced relationship to form a mold apparatus with a cavity therebetween for receiving lens molding material and for forming a lens of selected configuration, and sealing said first and second mold forms in said spaced relationship, said first and second mold form corresponding to surfaces of a prescription lens;
(b) injecting lens molding material comprising a liquid monomer, a thermal initiator, and a photosensitive initiator into said cavity between said mold forms;
(c) subsequent to said injecting step, heating throughout said mold apparatus sufficiently to activate said thermal initiator to form said lens molding material into a gel;
(d) subsequent to said heating step, subjecting said mold apparatus to ultraviolet light for a period of time sufficient to completely cure said lens molding material within said cavity from a gel into a hardened lens of optical quality;
and
(e) subsequent to said step of subjecting said mold apparatus to ultraviolet light, removing said hardened lens from said mold apparatus.

3 more elements

A method for curing plastic lenses comprising the steps of:

(a) arranging a first mold form and a second mold form in spaced relationship to form a mold apparatus with a cavity therebetween for receiving lens molding material and for forming a lens of selected configuration, and sealing said first and second mold forms in said spaced relationship, said first and second mold forms corresponding to surfaces of a prescription lens;
(b) injecting lens mold material comprising a liquid monomer and a photosensitive initiator into said cavity between said mold forms;
(c) curing said molding material sufficiently to form said lens molding material into a gel;
(d) subjecting said mold forms to ultraviolet light for a period of time sufficient to completely cure said lens molding material into a hardened lens of optical quality;
(e) removing said hardened lens from said mold apparatus;
(f) said step of creating a gel includes subjecting the lens molding material while in a cavity formed by said mold forms to UV light of a different intensity and wave length than a final curing step;
and
(g) said steps subjecting molding material to UV light includes controlling the intensity of said UV light received by the molding material.

5 more elements

Dependencies are inferred from the claim text.

Method for curing plastic lenses

Life of this patent

Method for curing plastic lenses

Life of this patent

Abstract

Claims24