Magnetic disk testing method and surface defect testing device
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
May 2, 2000
Grant Date -
N/A
app pub date -
Jun 23, 1998
filing date -
Jun 25, 1997
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
A magnetic disk testing method is provided, which comprises a surface defect test step of detecting, as defect data, the size of surface defect of a magnetic disk, the continuity thereof, the number thereof and the position thereof by testing magnetic disks optically and a classification step of classifying the magnetic disks to first magnetic disks, second magnetic disk and third magnetic disks on the basis of the defect data obtained in the surface defect test step. The first magnetic disks have surface defects which do not provide any problem on electric characteristics and are to be qualified through a subsequent certification test, the second magnetic disks require a further certification test for determining whether or not the surface defects thereof provide a problem on electric characteristics and the third magnetic disks have electric characteristics which are to be clearly disqualified without necessity of a further certification test, wherein the first magnetic disks are decided as qualified and the second magnetic disks are objects for the certifying test.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully