Process for manufacturing glass optical elements

Abstract

Processes for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 10.sup.9 poises, preheating molds at a temperature at which the glass material has a viscosity of from 10.sup.9 to 10.sup.12 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20.degree. C./minute or higher upon starting of, or during, or after the initial press, and removing a molded glass article from the molds after the temperature of the vicinity of the molding surfaces of the molds becomes a temperature equal to or lower than a temperature at which the glass material has a viscosity of 10.sup.12 poises.

Dependencies are inferred from the claim text.