Patent ID: 6823694
Filing Date: 2004-11-30
Classification: C03B

Abstract:
A method for manufacturing a glass optical element having at least one concave surface with no grinding or polishing, comprising:softening a glass molding material by heating, molding the softened material with a first mold having a first molding surface and a second mold having a second molding surface by applying a pressure, the first molding surface comprising a first concave forming surface, the second molding surface comprising one of a convex forming surface, a planar forming surface and a second concave forming surface, the second concave forming surface having a curvature radius greater than that of said first concave surface, whereby the applying of the pressure starts when the first mold and the second mold are at temperatures above a glass transition temperature of said glass molding material, cooling the first mold and the second mold so that temperatures of the first mold and the second mold reach temperatures equal to or lower than the glass transition temperature, and removing the cooled glass from either of said first mold or said second mold, wherein during the cooling, a second temperature of said second mold reaches the glass transition temperature prior to a time when a first temperature of said first mold reaches the glass transition temperature.