PREFORM FOR PRECISION PRESS FORMING, FORMING DIE, GLASS COMPACT MANUFACTURING METHOD USING THE DIE, AND OPTICAL ELEMENT MANUFACTURING METHOD

摘要

A preform for molding find press is provided not to destroy glass without making volume of the preform comparing to volume of lens drastically and to produce efficiently optical element having predetermined face precision. A preform for molding find press includes a rotation symmetry shaft, two end surfaces intersecting with the rotation symmetry shaft and one side connecting to circumference of the two end surfaces. The two end surfaces are independently a convex surface or a concave surface. A side of the preform for molding find press is a side formed by solidifying glass of melting state.