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US 4,391,621 AGranted
Method of making lenses having a spherical face
AssigneeAmerican Optical Corporation
InventorWalter P. Siegmund
Life of this patent
Estimating the term…
Abstract
A lens is formed of a section of glass clad glass rod ground and polished to a spherical shape of radius of curvature equal to that desired of a face of the lens. Remaining leachable cladding glass is removed leaving the lens with finished spherically curved opposite ends and an adaptability to modification by transaxial cutting and flat face finishing for plano-convex applications.
Claims7
A method of making lenses comprising the steps of:
- assembling a preform of glasses including a rod of lens glass and a surrounding cladding of leachable glass, said rod being of greater diametral size than desired of said lenses;
- heating and drawing the preform to such a reduced cross-sectional size as to bring said rod to the diameter desired of said lenses;
- cutting said drawn preform transaxially into a number of sections of lengths approximately equally the drawn preform diameter;
- grinding said sections into spherical configurations of radii of curvature equalling that desired of at least one face of each of said lenses;
- removing remaining leachable glasses from said sections whereby rod glasses each having at least one spherical face comprise said lenses;
- and
- polishing said spherical faces of said lenses at a stage of said method following said grinding step.
4 more elements
Dependencies are inferred from the claim text.