Patent ID: 7845192

Claim:
A method for the production of a substrate for an information recording medium, which comprises press-molding a glass in a softened state with a mold having an upper mold member and a lower mold member to produce a molded article blank having the form of a thin plate, wherein the glass in a softened state is press-molded without causing any surrounding edge portion of the blank under the production to come into contact with the mold members or parts used in the press molding, releasing the upper surface of the molded article from the upper mold member and mold parts, then cooling the molded article to produce the substrate blank at least having no notch portion and the surrounding edge portion having a free surface provided that the upper surface of the molded article is released from the upper mold member before the molded article is cooled to a temperature at or lower than the glass transition temperature, to obtain a substrate blank and cutting and polishing the substrate blank.