| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a glass substrate for a magnetic recording medium excellent in parallelism, to provide a polishing method of a glass substrate for polishing the glass substrate for a magnetic recording medium excellent in parallelism with high productivity, and to provide a manufacturing method for the glass substrate for a magnetic recording medium comprising the polishing method. <P>SOLUTION: At a polishing process of polishing both principal planes of a glass substrate for a magnetic recording medium, in the manufacturing method for a glass substrate for a magnetic recording medium of the present invention, the absolute value of a difference, Δtp (tp1-tp2), between the surface temperature tp1 measured at the inner peripheral end and the surface temperature tp2 measured at the outer peripheral end, of an upper platen of a double-side polishing device, when both principal planes of the glass substrate are simultaneously polished, is equal to or under 3°C. <P>COPYRIGHT: (C)2012,JPO&INPIT |
