| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a plate glass material for magnetic disks having excellent roundness and a glass substrate for magnetic disks in high efficiency. <P>SOLUTION: The method for producing the plate glass material G for magnetic disks comprises a dropping step of dropping a lump of molten glass LG and a pressing step of forming the plate glass material G by press-forming a gob GG held between faces of a pair of oppositely placed molds 121, 122 from both sides of a dropping path of the gob GG, wherein at least one of the pair of the molds 121, 122 has a concave form at the side of the dropping path of the gob GG. <P>COPYRIGHT: (C)2013,JPO&INPIT |
