Sidley Austin LLP
Method of manufacturing glass substrate for information recording medium
Molten glass is press-molded by a metallic die in which a cylindrical body is provided in a vertically standing manner at a central part of a bottom surface of a bottomed hole and a molding surface corresponding to a chamfering shape of an outer peripheral edge surface of a glass substrate is consecutively formed in an inner peripheral wall, and a glass substrate precursor provided with the chamfering shape axially consecutive on an outer peripheral surface thereof and a through hole formed at a central part thereof is thereby formed. The glass substrate precursor is cut perpendicular to an axial direction to be separated into respective glass substrates. Next, the respective glass substrates are subjected to a lapping process and a polishing process, if necessary, to produce a glass substrate as a final product. According to the manufacturing method, a glass substrate for information recording medium whose inner and outer peripheral edge surfaces are chamfered can be manufactured with an improved efficiency. Further, a glass substrate having a small diameter can be manufactured with a high efficiency.
Konica Minolta Opto, Inc.
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additional additional inventional
Shinji Toshiharu Yousuke
Sakai Mori Yamaguchi