METHOD FOR MOLDING GLASS OPTICAL ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a method for molding glass optical elements which press forms a glass blank softened by heating with preheated forming dies and is good in shape transferability and is capable of drastically softening the cycle time required for press forming. SOLUTION: In the method for molding the glass optical elements by press forming the glass blank to be formed which is softened by heating with the preheated molding dies; the temp. for heating the glass blank 1 is set at the temp. corresponding to the viscosity of the glass blank below 10<9> poises; the temp. for preheating the forming dies 34, 35 is set at the temp. corresponding to the viscosity of the glass blank from 10<9> to 10<12> poises; the glass blank softened by heating is initially pressurized for 3 to 60 seconds within the preheated molding dies; the parts near the forming surfaces 40, 41 of the molding dies are cooled at a rate of >=20 deg.C/min simultaneously with the start of the initial pressurization or during the course of the initial pressurization or after the end of the initial pressurization; and the glass molded body 2 is released from the molding dies after the temp. near the molding surface attains the temp. corresponding to the viscosity of 10<12> poises or below.