Glass-ceramic support for fusing and sagging ophthmalmic multifocal lenses
AssigneeCorning Incorporated
InventorsMilford L. Buckley, Harry L. Burke
Life of this patent
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Abstract
There is disclosed a low expansion glass-ceramic substrate for supporting a glass multifocal lens assembly during a fusing or sagging heat treatment. The substrate has baked on its supporting surface a paint composed essentially of titania, alumina and a mica.
Claims21
A substrate for supporting a multifocal lens assembly during heat treatment comprising a low expansion glass ceramic body having an upper surface with a predetermined curvature, having a baked-on coating of a paint in which the solids are composed essentially of titania, alumina and a mica and being capable of withstanding temperatures up to 750.degree. C.
A method of supporting a multifocal ophthalmic lens assembly during a heat treatment which comprises providing a low expansion glass-ceramic body, surfacing the upper surface of the body to a predetermined curvature, applying a coating of a titania-alumina-mica paint to the upper surface, baking the coating, said coating being capable of withstanding temperature up to 750.degree. C. and thereafter mounting the multifocal assembly on said coated surface for heat treatment.
A method of heat treating a multifocal ophthalmic lens assembly which comprises providing a low expansion glass-ceramic body, surfacing the upper surface of the body to a predetermined curvature, applying a coating of a titania-alumina-mica paint to the upper surface, baking the coating said coating being capable of withstanding temperatures up to 750.degree. C., and thereafter mounting the multifocal assembly on said coated surface for heat treatment and subjecting said assembly to an elevated temperature for a predetermined time.
Dependencies are inferred from the claim text.