| 摘要 |
PURPOSE: To reduce the affection of strain and improve optical performance by charging material for optical element, which is treated by density unifying treatment previously, into a space enclosed by a top force, a bottom force and an intermediate mold. CONSTITUTION: A pellet, annealed in an electric furnace at 150 deg.C for C1hr previously to remove strain, is dropped and supplied into a mold, in which an intermediate mold 14 is set on a bottom force 12, in a pellet supplying stage. Next, a top force 11 is set on the intermediate mold 14 in a preliminary stage and, thereafter, the molds are transferred to next preliminary stage 22. Subsequently, an upper heater block 27 is lowered to heat and, thereafter, the upper heater block 27 is elevated and the molds are transferred to a molding stage 23. An upper heater block 28 is lowered there and is contacted with the top force, then, the molds are transferred to a cooling stage 24 after 60sec has elapsed and the other upper heater block 29 is lowered to contact it with the top force. The molds are shifted to a water cooling board 25 after 60sec has elapsed, then, the molds are transferred to the outside of the system after 60sec has elapsed. |
