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Browse Prior Art Database

Side-Erase Test

IP.com Disclosure Number: IPCOM000118734D
Original Publication Date: 1997-Jun-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Heinrich, V: AUTHOR [+2]

Abstract

Disclosed is a method to test the side-erase effect of a write element on a normal spin stand.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

Side-Erase Test

      Disclosed is a method to test the side-erase effect of a write
element on a normal spin stand.

      The smaller the write elements are, the more critical the write
operation will become.  The track density is increased and,
therefore, the side writing and erase effects have to be carefully
controlled. The  side write effect is caused primarily by a strong
stray field and may erase part of the previously written adjacent
track.  To investigate this effect, the written information of a disk
can be made visible by a  Magnetic Force Microscope (MFM).  This
method clearly shows the side erase bands but is time consuming.

      The described method uses the normal magnetic tester
features.  Accordingly, it can easily be implemented or attached to a
common magnetic test.  The features of the test stand that are used
are an adjustable filter card to read only at a certain frequency and
a synthesizer to write with a selected frequency.

      The principle is to write one track (e.g., with 10 MHz), move
half track pitch offtrack, and overwrite half of the previously
written track with a frequency which is close to the first one (e.g.,
10.5 MHz).  The amplitudes are read on track with an adjustable
filter card  after the tracks are written (U10, U10.5).  Then, the
magnetoresistive read element is moved to the center between both
written tracks and the  amplitudes of the written frequencies are
again read (u10, u10.5). This  can be ...