METHOD FOR MANUFACTURING OPTICAL ELEMENT

PROBLEM TO BE SOLVED: To obtain an optical element having no projection or burr by preventing a softened glass raw material from intruding into a gap between a convex part and a flat part continuing therefrom of a lower die. SOLUTION: The method for manufacturing an optical element includes the steps of: disposing a lower die 20 having a flanged ring 26 to hold a glass raw material 30 in the periphery of a molding face, opposing to an upper die 18 with the center axis aligned to the lower die 20; heating the glass raw material 30 while held by the flanged ring 26, followed by moving the lower die 20 to approach the upper die 18 while the flanged ring 26 is stopped, and starting to pressurize the glass raw material 30; and moving the lower die 20 with the flanged ring 26 as integrated during pressurizing, and further moving to pressurize the glass raw material 30 to obtain a specified center thickness. COPYRIGHT: (C)2010,JPO&INPIT