| 摘要 |
PURPOSE:To facilitate release of a lens from a mold by forming plural recesses in the forming surface of at least one die of the opposed dies outside the effective diameter of the lens. CONSTITUTION:The forming mold 10 is used for forming a concave lens, and its forming surface 11 is made convex. Plural intermediate recesses 12 are formed in the forming surface 11 outside the etfective diameter r of the lens. The recesses 12 are arranged at regular intervals along the cirnmference of the diameter K. Glass is introduced into the recess 12 when a lens is formed, and the protruding part of glass overflows from the recess 12 by the difference in contraction from the mold when the lens is contracted. Accordingly, a gap is formed between the forming surface 11 of the mold 10 and the surface of glass to be formed between the recesses 12 and 12. Consequently, since air is introduced inside (mold or lens center side) from the gap, the lens is easily released from the mold 10.
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