METHOD FOR MOLDING OPTICAL ELEMENT

PURPOSE:To mass-produce efficiently high-precision optical elements such as optical lens by clamping voluminous softened glass with a couple of forming dies and controlling the relative distance between both forming dies. CONSTITUTION:Platy softened glass 2 is poured from an outflow port 1 of the conduit of an optical glass melting device, clamped with a couple of forming dies 3 and 4 having plural high-precision forming surfaces and compression is started. The glass 2 is deformed by the compression and stuck fast to a flat surface 3a and an aspheric surfaces 4a. The relative interval between the forming dies 3 and 4 is shortened in correspondence with the cooling of the glass 2, and the glass is compressed while allowing the excess glass to escape into a glass escape groove 6. When the temp. of the glass 2 is lowered to a temp. below the strain point and the forming dies 3 and 4 reach specified positions, the pressure is turned off and the molded glass 2 is taken out and annealed. A molding satisfying the high-precision characteristic required for an optical element can be obtained by this method.