| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass blank for information recording medium substrate having high planarity even when manufacturing the glass blank which is thinner. SOLUTION: There is provided the method for manufacturing the glass blank for information recording medium substrate through at least: a glass gob drawing process of pressing a glass gob in the softened state on a lower mold by means of an upper mold and the lower mold, and drawing the glass gob between two press surfaces; a stripping process of stripping a disk-shaped glass, which is completely drawn until completion and is left in the softened state in a state of being held between the two press surfaces, from the press surface of the upper mold; and a cooling process of substantially symmetrically cooling the neighborhood of outer peripheral edge of the disk-shaped glass in the softened state on the basis of the center part of the disk-shaped glass in the softened state at timings before and after performing the stripping process. A method for manufacturing a substrate for information recording medium and a method for manufacturing information recording medium using the method for manufacturing a glass blank for information recording medium are also provided. COPYRIGHT: (C)2011,JPO&INPIT |
