Process for preparation of glass optical elements

摘要

A method disclosed can mold glass optical elements having a good surface precision with a relatively short cycle time even where glass optical elements are manufactured in largely transforming a glass material. This method is, for example, a molding method for glass optical elements including the step of pressing a glass molding material softened by heat until the center thickness of the glass molded article becomes 70% of the center thickness of the glass molding material to produce the glass molded article. The preheat temperature of the mold is set to a temperature that the average of the temperatures around molding surfaces of upper and lower molds constituting the mold is a temperature that the glass molding material indicates a viscosity of X poises; the heating temperature of the glass molding material is set to a temperature that the glass molding material indicates a viscosity of Y poises; the viscosity X and the viscosity Y satisfy the following formulas.