Manufacturing method for a glass substrate for magnetic disk
AssigneeHoya Corporation
InventorsShinji EDA, Hideki Isono, Akira Murakami
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Abstract
The present invention provides a manufacturing method of a sheet glass material excellent in flatness. A manufacturing method of glass substrate for magnetic disk including a pair of principal surfaces, the method comprising the steps of: dropping process for dropping a lump of molten glass; pressing process for forming a sheet glass material by performing press forming to the lump while sandwiching the lump from both sides of the dropping path of the lump with facing surfaces of a pair of dies, the pair of dies being set to substantially the same temperature; and processing process for processing the sheet glass material, while the lump drops down while revolving around its dropping axis.
Claims7
A manufacturing method of glass substrate for magnetic disk including a pair of principal surfaces, the method comprising the steps of:
- dropping process for dropping a lump of molten glass;
- pressing process for forming a sheet glass material by performing press forming to the lump while sandwiching the lump from both sides of the dropping path of the lump with facing surfaces of a pair of dies, the pair of dies being set to substantially the same temperature;
- and
- processing process for processing the sheet glass material,
- while the lump drops down while revolving around its dropping axis.
Dependencies are inferred from the claim text.