Title:
METHOD FOR PRODUCING GLASS SUBSTRATE FOR MAGNETIC DISC AND METHOD FOR PRODUCING MAGNETIC DISC
Document Type and Number:
WIPO Patent Application WO/2007/111253
Kind Code:
A1
Abstract:
In a method for cutting a glass substrate from a glass material by forming a cutting streak on one side of a planar glass material and making the cut stream advance in the thickness direction of the glass material, the cut streak is formed selectively on the surface having relatively small surface undulation out of the two opposing surfaces of the glass material. In case of a glass material rendered planar on molten metal, the surface touching the molten metal is selected as the surface having relatively small surface undulation. When the glass substrate on a disc is cut out from the glass material, cutting is performed under such a condition as any one of the plate thickness and radius of the glass material and the maximum height of surface undulation of the glass material satisfy a predetermined relation.
Inventors:
JOSEPH MARQUEZ (PH)
ELMER MAHIA (PH)
ELMER MAHIA (PH)
Application Number:
PCT/JP2007/056035
Publication Date:
October 04, 2007
Filing Date:
March 23, 2007
Export Citation:
Assignee:
HOYA CORP (JP)
HOYA GLASS DISK PHILIPPINES IN (PH)
JOSEPH MARQUEZ (PH)
ELMER MAHIA (PH)
HOYA GLASS DISK PHILIPPINES IN (PH)
JOSEPH MARQUEZ (PH)
ELMER MAHIA (PH)
International Classes:
C03B33/023; C03B33/04; G11B5/84
Domestic Patent References:
| WO2002076675A1 | 2002-10-03 |
Foreign References:
| JP2973354B2 | 1999-11-08 | |||
| JP2005141824A | 2005-06-02 |
Attorney, Agent or Firm:
IKEDA, Noriyasu et al. (4-10 Nishishinbashi 1-chome,Minato-k, Tokyo 03, JP)
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