| 摘要 |
PURPOSE:To the titled device capable of producing high precision lens, tolerating variability of material volume in a large range, eliminating centering operation, wherein coefficients of expansion of a barrel mold to lens material and of barrel mold holder are set at given values and an excess glass relief part is formed. CONSTITUTION:The glass lens material 10 is fed to the through hole 3 of the barrel mold 2, the upper mold 5 is engaged with the barrel mold, and the barrel mold holder 6 is heated to soften the lens material 10. The upper mold 5 is lowered and the lens material 10 is pressed and molded into a desired shape. The molded lens is annealed to complete the glass lens 1. Release is made easy and shape precision lens face can be raised by making a coefficient of the barrel mold 2 smaller than that of the lens material 10 and a coefficient of expansion of the barrel mold holder 6 larger than that of the lens material 10. An excess glass relief part is formed by finishing chamfering in the tapered state 5A at the outer edge part of the molding face of the mold 5 and a product with fixed thickness is obtained by prescribing the lowering position of the upper mold 5 by the top of the barrel mold holder 6 even if variability of volume of the glass material 10 is large. |
