Title:
磁気ディスク用ガラス基板および磁気ディスク
Document Type and Number:
Japanese Patent JP5860173
Kind Code:
B2
Abstract:
A magnetic-disk glass substrate capable of suppressing turbulence of air flow in a vicinity of an outer circumferential side edge portion of the magnetic disk and suppressing disk flutter is provided. This magnetic-disk glass substrate includes a pair of main surfaces, a side wall surface formed on an outer circumferential side edge surface, and chamfered surfaces interposed between the side wall surface and the main surfaces, respectively. The side wall surface has a roundness of 1.5 μm or less. A difference in radius between an inscribed circle and a circumcircle of a plurality of outlines of the side wall surface at a plurality of positions that include a central position of the magnetic-disk glass substrate in a thickness direction and are different from each other in the thickness direction is 5 μm or less.
Inventors:
Tamaki Masanori
Application Number:
JP2014554624A
Publication Date:
February 16, 2016
Filing Date:
December 27, 2013
Export Citation:
Assignee:
HOYA CORPORATION
International Classes:
G11B5/73; G11B5/84
Domestic Patent References:
| JP2008310842A | 2008-12-25 | |||
| JP2011198429A | 2011-10-06 | |||
| JP2004079009A | 2004-03-11 | |||
| JP2012113802A | 2012-06-14 | |||
| JP2005293840A | 2005-10-20 | |||
| JP2008310842A | 2008-12-25 | |||
| JP2011198429A | 2011-10-06 |
Attorney, Agent or Firm:
Global IP Tokyo Patent Business Corporation