| 摘要 |
The invention provides a process for stably producing a preform for precision press-molding of a high-quality preform composed of a glass with high refractive index and low dispersibility, and a process for producing an optical element using the preform. The process for producing the preform for precision press-molding comprises obtaining a fusion glass block by separating an outflow fusion glass, and molding the fusion glass block to the preform duing a cooling process, wherein the glass composing the preform uses a glass free of alkalescent metal oxide and having a refractive index (nd) more than 1.83, an Abbe number (vd) more than 40, applying a wind pressure on the separated fusion glass to float the separated fusion glass, while molding the separated fusion glass as the preform. The process for producing the optical element comprises heating the preform for precision press-molding produced by the above preform producting process, and precision press-molding by a press-molding mould. |
