Browse Prior Art Database

Hard Disk Drive for Low Temperature

IP.com Disclosure Number: IPCOM000116372D
Original Publication Date: 1995-Sep-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Ando, H: AUTHOR [+4]

Abstract

Disclosed is an error recovery method for a Hard Disk Drive which is used in low temperature condition. This method claims that bearing grease stirring by actuator motion, without servo information, can prevent seek and/or positioning error due to higher viscosity of bearing grease at a low temperature.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Hard Disk Drive for Low Temperature

      Disclosed is an error recovery method for a Hard Disk Drive
which is used in low temperature condition.  This method claims that
bearing grease stirring by actuator motion, without servo
information, can prevent seek and/or positioning error due to higher
viscosity of bearing grease at a low temperature.

      The Figure shows the example of a Hard Disk Drive.  Actuator(3)
has read/write heads and is supported by ball bearings to move and
settle head(2) on data tracks of Disk(1).  Under low temperature
condition, the viscosity of grease used in this ball bearings gets
higher, and it disturbs the actuator to follow the data track to seek
to another track.  To avoid this problem, actuator motion itself is
effective because it mixes up the bearing grease.  This can be
achieved by seeking operation.  When this problem occurres, normal
seek operation with servo data cannot be performed.

      Therefore, under a low temperature condition, the following
operation is effective to avoid seek/positioning failure when the
drive has started up or the seek/positioning failure has occurred:
  1.  When seek/positioning failure occurres, put a DC current on
Voice
       Coil Motor (VCM) and hold this condition on several duration.
It
       causes actuator motion and it stops at this crash stop.
  2.  Turn to the direction of current, and hold on several
durations.
       It also causes the actuator counter...