| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass substrate which can improve the production quantity of a glass substrate and manufacture a suitable glass substrate when manufacturing the glass substrate using a down draw process. <P>SOLUTION: In the method, molten glass is formed into sheet glass by a down draw process in a molding step. A cooling step includes a first cooling step, a second cooling step, and a third cooling step. In the first cooling step, the sheet glass is cooled at a first average cooling rate until the temperature of the central region of the sheet glass becomes an annealing point. In the second cooling step, the sheet glass is cooled at a second average cooling rate until the temperature of the central region becomes from the annealing point to the strain point-50°C. In the third cooling step, the sheet glass is cooled at a third average cooling rate until the temperature of the central region becomes from the strain point-50°C to the strain point-200°C. Furthermore, the first average cooling rate is 5.0°C/s or higher. The first average cooling rate is faster than the third average cooling rate. Furthermore, the third average cooling rate is faster than the second average cooling rate. <P>COPYRIGHT: (C)2013,JPO&INPIT |
