Press molding method for manufacturing of glass substrate
The present invention relates to a glass substrate of which the outer periphery portion is unprocessed. The present invention also relates to a manufacturing method for a glass substrate of which the outer periphery portion is unprocessed, characterized in that a first lapping process, a second lapping process, a polishing process and a washing process are carried out after a press molding process is carried out so as to compress glass between an upper mold and a lower mold without regulating the edge surface of the outer periphery portion of the glass and, then, a crystallization process or an annealing process is carried out.
1. A manufacturing method for a glass substrate, comprising the steps of:
melting a glass material;
flowing the melted glass into a lower mold;
press molding the glass between an upper mold and the lower mold into a glass substrate;
detecting the center of gravity of the glass substrate; and
creating a center hole so that the center of gravity becomes the center of the center hole.
2. A manufacturing method according to claim 1 , wherein the center of gravity is detected by carrying out image processing on a two dimensional image as viewed from the direction of the thickness of the glass substrate.