Browse Prior Art Database

Variable Magnet Force in L/UL System for HDD

IP.com Disclosure Number: IPCOM000123750D
Original Publication Date: 1999-Apr-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 1 page(s) / 40K

Publishing Venue

IBM

Related People

Ogasawara, K: AUTHOR

Abstract

This article describes the new concept which secures the head retract in the Ramp Load/Unload System in HDD.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 80% of the total text.

Variable Magnet Force in L/UL System for HDD

   This article describes the new concept which secures the
head retract in the Ramp Load/Unload System in HDD.

   In the L/UL System, it is important to secure
unloading/retracting the Head Arm to the home position on the ramp in
order to guarantee the mechanical latch function.  One of the
solution for this design requirement is to use the permanent magnet
at the OD_CS position to hold the head arm back on the home position
on the ramp, and have it stay there.

   This magnet is effective to prevent the head arm going
out from the home position, however, this magnet makes it difficult
to load the head toward the disk.  There is a trade off between the
two.  The new idea which will be described below will solve this
design trade off.

   The basic idea of this invention is to make the magnet
force variable depending upon the head position.  If the head arm is
on the ramp, the magnetic force should be big enough, while once the
arm is back on the home position on the ramp, the magnetic force
should be relatively small for the next loading operation.  On the
other word, magnetic force is bigger when arm is still unloading
process, but it becomes smaller after the unloading is completed and
it prepares for the next loading.

   This variable magnetic force can be achieved by a simple
mechanics with a few parts; a magnet, a housing and "a distance
holder bar".  The distance holder bar is attached to the magnet and
they a...