Method of manufacturing thin-plate glass article, method of manufacturing glass substrate for information recording medium, and method of manufacturing magnetic recording medium

摘要

There are disclosed a method of manufacturing a thin-plate glass having a good flatness with a high mass productivity and a method of manufacturing a high-quality and high-performance glass substrate for an information recording medium and a magnetic recording medium with a high mass productivity. A glass gob is press-formed between upper and lower dies to form a thin-plate glass. The press forming is finished when the inside of the thin-plate glass is at a softening point Ts or a higher temperature. Subsequently, warp modification pressing is performed to modify a warp of the thin-plate glass. The warp modification pressing is finished when the inside of the thin-plate glass is at a transition point Tg or a higher temperature.