Title:
GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING MEDIUM
Document Type and Number:
WIPO Patent Application WO/2017/115473
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide a glass substrate for a magnetic recording medium such that the adhesion of foreign substances onto the main surface that is caused by minor scratches on the outer peripheral end surface can be minimized. The glass substrate for a magnetic recording medium according to the present invention is donut shaped and includes a pair of main surfaces, an outer peripheral end surface, and an inner peripheral end surface. The outer peripheral end surface has an outer peripheral lateral surface and a pair of outer peripheral chamfers. The proportion of the surface area of the outer peripheral end surface occupied by recess defects is 0.05% or less.
Inventors:
YOSHIDA KARA (JP)
Application Number:
PCT/JP2016/062148
Publication Date:
July 06, 2017
Filing Date:
April 15, 2016
Export Citation:
Assignee:
ASAHI GLASS CO LTD (JP)
International Classes:
G11B5/73; G11B5/02; G11B5/84
Domestic Patent References:
| WO2014050241A1 | 2014-04-03 | |||
| WO2014208717A1 | 2014-12-31 |
Foreign References:
| JP2015069674A | 2015-04-13 | |||
| JPH0972722A | 1997-03-18 | |||
| JP2002168793A | 2002-06-14 | |||
| JPH08235543A | 1996-09-13 | |||
| JP2012185891A | 2012-09-27 |
Attorney, Agent or Firm:
EIKOH PATENT FIRM, P.C. (JP)
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