| 摘要 |
PROBLEM TO BE SOLVED: To prevent a molding material from entering into a clearance between molds sometimes formed in the molding by pressurizing a material for an optical element between a pair of molding molds constituted of a frame mold and an inserted mold inserted into the frame mold, and producing an optical element having a bent part and a flat part. SOLUTION: A material 10 for an optical element softened at a high temperature and in a shape of an ellipse or a sphere is inserted in a molding space of a pair of molds, and subjected to a pressure forming. The pair of the molds comprises an upper mold 11a composed of a frame mold 9A and a nest-type mold 8A to be inserted therein, and a lower mold 11b composed of a frame mold 9B and a nest-type mold 8B to be inserted therein. The inner face of the nest-type mold 8A of the upper mold 11a comprises a flat part 8a and a ring-like protruded part 8b at the neighbor thereof. The inner face of the nest-type mold 8B of the lower mold 11b is formed into a convexly curved face so as to protrude into the molding space. As the result, a wrong phenomenon such as barr, chipping and breakage of the mold, which sometimes occurs, is previously prevented.
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