US Patent 7845192 Methods for producing substrate blank

A method for producing a thin-plate-shaped substrate blank that is an intermediate for a glass substrate, in which the occurrence of undulation is prevented and the substrate blank is produced with high accuracy, the method comprising press-molding a glass in a softened state with a mold having an upper mold member and a lower mold member to produce the thin-plate-shaped substrate blank, wherein the glass in a softened state is press-molded without causing any surrounding edge portion of the substrate blank under the production to come into contact with the mold, to produce the substrate blank at least having no notch portion.