| 摘要 |
PURPOSE:To enable continuous forming for producing long-sized optical elements or large size optical elements having special form under optimum forming conditions, by inserting a glass blank held by a forming die continuously into a tubular heater at a specified temp. and forming the glass blank continuously under a specified pressure. CONSTITUTION:In a process for forming, for example, a pentagonal prism having a pentagonal sectional shape from a glass blank, a forming die 2 contg. the glass blank 3 in a forming space 7 of a pair of die section 5, 6 is inserted appropriately into a cylindrical guiding member, and the guiding member is arranged to an inlet section 4a of a tubular heater 4, then the forming die 2 is forced continuously into the tubular heater 4 by means of a pusher. The glass blank 3 in each forming die 2 is softened by heating uniformly by means of the cylindrical heater 4. The glass blank 3 is deformed gradually and forms finally a pentagonal prism (formed product) having the desired shape by the forming effect of faces 5c, 5d, 6c, 6d, 6e for forming the prism forming the forming space section 7.
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