Preform for molding an optical element and optical element molding method

摘要

A preform (10) for molding an optical element includes an element body forming portion for forming an element body having optical surfaces and a flange forming portion provided in a periphery of the element body forming portion, and when the preform is deformed through heating and compressing inside a space enclosed by an upper die and a lower die and a barrel die (26) of a molding device, the outer periphery of the flange forming portion is formed to have abutment portions (17) that abut on the inner surface of the barrel die and non-abutment portions (18) that do not abut on the inner surface of the barrel die.