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AssigneeHoya Corporation
InventorsHideki Isono, Hidekazu Tanino, Akira Murakami, Takashi Sato, Masamune Sato
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A method for manufacturing a glass blank for magnetic disk and a method for manufacturing a glass substrate for magnetic disk are provided which are capable of producing a glass blank for magnetic disk having a good surface waviness by press forming. The method includes a forming process of press-forming a lump of molten glass using a pair of dies, wherein in the forming process, press forming is performed using thermally equalizing means for reducing a difference in temperature in the press forming surface of the die during pressing of the molten glass.
A method for manufacturing a glass blank for magnetic disk, the method including a forming process of press-forming a lump of molten glass using a pair of dies, the method comprising:
A method for manufacturing a glass blank for magnetic disk, the method including a forming process of forming a plate-shaped glass blank by press-forming a falling molten glass in a direction orthogonal to the falling direction using a pair of dies while the molten glass is falling, wherein the forming process comprises a thermally equalizing process for reducing a difference in temperature of the pair of dies during a period of time until a new molten glass is press-formed after the dies are opened.
A method for manufacturing a glass blank for magnetic disk, the method comprising:
A method for manufacturing a glass blank for magnetic disk, the method comprising a forming process of press-forming a lump of molten glass using a pair of dies, wherein in the forming process, the lump of molten glass is press-formed while falling from a direction orthogonal to the falling direction using a pair of dies so that a difference in temperature of the pair of dies is 10° C. or less, the difference being measured at positions of the pair of dies facing each other.
A method for manufacturing a glass blank for magnetic disk, the method comprising a forming process of press-forming a lump of molten glass while falling from a direction orthogonal to the falling direction using a pair of dies, wherein in the forming process, the lump of molten glass is press-formed so that flatness of the glass blank is 8 μm or less.
A method for manufacturing a glass blank for magnetic disk, the method comprising a forming process of forming a plate-shaped glass blank by press-forming a falling molten glass in a direction orthogonal to the falling direction using a pair of dies while the molten glass is falling, wherein each of the pair of dies includes a passage for introducing a gas to a space formed by closing of the pair of dies, and in the forming process, the gas is supplied to the space through the passage of each die while the pair of dies are closed.
Dependencies are inferred from the claim text.