Patent ID: 7395679
Filing Date: 2008-07-08
Classification: C03B

Abstract:
1. A method of manufacturing a glass substrate for information recording medium, comprising the steps of: forming a glass substrate precursor provided with a plurality of chamfered ridges, each chamfered ridge extending around the circumference of the glass substrate precursor and positioned axially consecutive on an outer peripheral surface of the glass substrate precursor and a through hole formed at a central part of the glass substrate precursor, said glass substrate precursor being formed by press-molding molten glass by a metallic die having a cylindrical body provided in a vertically standing manner at a central part of a bottom surface of a bottomed hole and having a molding surface corresponding to the plurality of chamfered ridges in an inner peripheral wall; and cutting the glass substrate precursor perpendicular to an axial direction between the chamfered ridges to divide the glass substrate precursor into respective glass substrates.