GLASS SUBSTRATE FOR INFORMATION RECORDING MEDIUM AND INFORMATION RECORDING MEDIUM EMPLOYING SAME

摘要

In a chemically reinforced glass for information recording medium, a chemically reinforced layer (13) is respectively arranged on the outer circumferential surface and the inner circumferential surface but is not substantially arranged on the upper side (11) and the lower side (12) on which an information recording layer is formed. Accuracy of shape such as flatness, and strength can be thereby enhanced without requiring a high precision substrate polishing technology.