Polarized ophthalmic lenses and methods for making same
AssigneeAlcat, Incorporated
InventorsMichael Barry Smith, Gerard Nault
Life of this patent
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Abstract
A laminated light-polarizing composite lens is efficiently produced by bonding a pre-formed polarized sheet to the front convex surface of a molded polycarbonate lens in an autoclave. Excellent optical properties are obtained by the replication from a polished glass surface to the front surface of the lens. The outer surface layer of the finished lens is isotropic and thus does not produce unwanted birefringence effects. The method is especially well suited for the production of optically corrected decentered polycarbonate lenses. The process is simple and easily changed to produce lenses with different base curves and colors.
Claims9
A method for producing a light polarizing sub-laminating comprising:
- (a) providing a sheet which comprises in order:
- (i) a light polarizing layer comprising a stretched polyvinyl alcohol film containing a polarizing dye,
- (ii) an isotropic support layer for the light polarizing layer, and
- (iii) a protective removable skin;
- (b) treating the light polarizing layer with a siloxane coupling agent;
- (c) laminating a polyurethane layer to the treated light polarizing layer;
- (d) forming at least one curved cavity in the sheet by supporting the sheet on a plate having at least one opening, heating the sheet, and applying a vacuum to the protective removable skin to pull a portion of the sheet into the at least one opening to form the at least one curved cavity;
- and
- e) removing the protective removable skin to form the light polarizing sub-laminate.
A method for producing a light polarizing subassembly comprising:
- (a) providing a mold having at least one concave precision mold cavity;
- (b) inserting a light polarizing sub-laminate having a first surface and a second surface into the concave precision mold cavity with the first surface contacting the concave precision mold cavity and the second surface defining a concave cavity for receiving a lens blank;
- (c) inserting a lens blank into the concave cavity defined by the second surface;
- and
- (d) subjecting the concave precision mold cavity the light polarizing sub-laminate, and the lens blank to a vacuum and to autoclaving to form the light polarizing sub-laminate and the lens blank into the light polarizing subassembly, said autoclaving causing the first surface to acquire the shape of the concave precision mold cavity.
A method for producing a light polarizing subassembly comprising:
- (A) producing a light polarizing sub-laminate by:
- (i) providing a sheet which comprises in order:
- (a) a light polarizing layer comprising a stretched polyvinyl alcohol film containing a polarizing dye,
- (b) an isotropic support layer for the light polarizing layer, and
- (c) a protective removable skin;
- (ii) treating the light polarizing layer with a siloxane coupling agent;
- (iii) laminating a polyurethane layer to the treated light polarizing layer;
- (iv) forming at least one curved cavity in the sheet by supporting the sheet on a plate having at least one opening, heating the sheet, and applying a vacuum to the protective removable skin to pull a portion of the sheet into the at least one opening to form the at least one cavity;
- and
- (v) removing the protective removable skin to form the light polarizing sub-laminate;
- (B) providing a mold having at least one concave precision mold cavity;
- (C) inserting the light polarizing sub-laminate produced in step (A) into the precision mold cavity with the isotropic support layer contacting the concave precision mold cavity and the polyurethane layer defining a concave cavity for receiving a lens blank;
- (D) inserting a lens blank into the concave cavity defined by the polyurethane layer;
- and
- (E) autoclaving the light polarizing sub-laminate and the lens blank to form the light polarizing subassembly, said autoclaving causing the isotropic support layer to acquire the shape of the concave precision mold cavity.
Dependencies are inferred from the claim text.