METHOD OF MANUFACTURING GLASS SUBSTRATE FOR INFORMATION RECORDING MEDIA, GLASS SUBSTRATE FOR INFORMATION RECORDING MEDIA MANUFACTURED USING THE METHOD, AND INFORMATION RECORDING MEDIUM USING THE GLASS SUBSTRATE

摘要

There are provided a method of manufacturing a glass substrate for information recording media that allows the inner and outer peripheral edge surfaces of the glass substrate for information recording media to be smoothed easily and inexpensively, a glass substrate for information recording media manufactured using this method, and an information recording medium using this glass substrate. A donut-shaped glass disk for information recording media having an outer peripheral edge surface and an inner peripheral edge surface is prepared. At least one of the outer peripheral edge surface and the inner peripheral edge surface of the glass disk is smoothed by melt-heating to a temperature at or above the softening point of the glass by irradiating with at least one laser beam. As a result, at least one of the outer peripheral edge surface and the inner peripheral edge surface of the glass disk becomes smooth and rounded, and hence a polishing step used in a conventional method can be omitted, and moreover chamfering in a grinding step can also be omitted.