Title:
RING-SHAPED GLASS PLATE PRODUCTION METHOD, MAGNETIC DISC GLASS SUBSTRATE PRODUCTION METHOD, MAGNETIC DISC PRODUCTION METHOD, RING-SHAPED GLASS PLATE, MAGNETIC DISC GLASS SUBSTRATE, AND MAGNETIC DISC
Document Type and Number:
WIPO Patent Application WO/2021/020587
Kind Code:
A1
Abstract:
A method for producing a ring-shaped glass plate having an outer peripheral edge surface and an inner peripheral edge surface and having a plate thickness of 0.6 mm or thinner, the method comprising the process of producing the ring-shaped glass plate by irradiating laser light on the outer peripheral edge surface and the inner peripheral edge surface of a ring-shaped glass raw plate to melt the outer peripheral edge surface and the inner peripheral edge surface into melted surfaces, while irradiating the laser light in such a manner that the surface roughness of the melted surface for both the outer peripheral edge surface and the inner peripheral edge surface is an arithmetic mean roughness Ra of 0.1 μm or less and such that the surface roughness of the melted surface on the inner peripheral edge surface is greater than the surface roughness of the melted surface on the outer peripheral edge surface.
Inventors:
AZUMA SHUHEI (VN)
Application Number:
PCT/JP2020/029591
Publication Date:
February 04, 2021
Filing Date:
July 31, 2020
Export Citation:
Assignee:
HOYA CORP (JP)
International Classes:
C03B29/00; B23K26/354; B23K26/53; C03B33/04; C03B33/09; C03C19/00; G11B5/73; G11B5/84
Domestic Patent References:
| WO2016111158A1 | 2016-07-14 |
Foreign References:
| JP2002150546A | 2002-05-24 | |||
| JP2015181085A | 2015-10-15 | |||
| JP2006018998A | 2006-01-19 | |||
| JP2011104713A | 2011-06-02 | |||
| JP2010108592A | 2010-05-13 | |||
| JP2003160348A | 2003-06-03 | |||
| JP2010501456A | 2010-01-21 | |||
| JP2001335336A | 2001-12-04 |
Attorney, Agent or Firm:
GLOBAL IP TOKYO (JP)
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