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Low Noise, No Bias Erase Method for Thin Film Disks

IP.com Disclosure Number: IPCOM000111192D
Original Publication Date: 1994-Feb-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Malagrino, GD: AUTHOR [+2]

Abstract

Described is a low noise, no bias, erase method for magnetic thin film media.

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This is the abbreviated version, containing approximately 100% of the total text.

Low Noise, No Bias Erase Method for Thin Film Disks

      Described is a low noise, no bias, erase method for magnetic
thin film media.

      Use two disc shaped permanent magnets 1; one on each side of
the disk 2, with the direction of magnetization for each magnet
opposing each other.  This will cancel out the vertical fields and
aid the horizontal fields that are desired to do the erase.  The
strength and spacing of the magnets 1 must be such as to provide
field in the plane of the disk 2 greater than Hc max.  (max.  media
coercivity).

Sweep the magnets 1 from the ID to off the OD of the disk 2 (Figure).

      The disc type shape of the magnets will provide a field so that
the last field seen by the disk will be in the radial direction of
the disk, regardless of the path taken by the magnet in moving from
ID to OD.