Browse Prior Art Database

Pseudo-AC Erase Method by Perpendicular DC Erase

IP.com Disclosure Number: IPCOM000109256D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 40K

Publishing Venue

IBM

Related People

Harada, Y: AUTHOR [+3]

Abstract

Disclosed is a technique to erase all of the recorded signals on a magnetic medium at one time using high DC magnetic field.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Pseudo-AC Erase Method by Perpendicular DC Erase

       Disclosed is a technique to erase all of the recorded
signals on a magnetic medium at one time using high DC magnetic
field.

      The principle of this technique is as follows.  The figure
shows a conceptional configuration of this invention.  A magnetic
medium as magnetic disk which is used for HDD (Hard Disk Drive) is
put in the High DC Magnetic Field B.  The magnetic field B is
perpendicular to the surface of the disk.  The data which were
recorded on the disk before it was put in the High DC Magnetic Field
B are completely erased after going through the field B.

      The direction of the magnetic dipole is in parallel with the
direction of the surface before going through the high DC field B.
When the disk stays in the high DC magnetic field B, the direction of
the magnetic dipole becomes in parallel with the DC field B.  After
the DC field B disappears, the direction of the dipole will be in
parallel or anti-parallel with the surface.  The directions of the
dipole are randomly decided because of a 50/50 chance whether it
becomes parallel or anti-parallel with respect to the surface.

      In summary, this technique has the same effect as AC ERASE.