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Browse Prior Art Database

Write Protection Algorithm for Sector Servo System

IP.com Disclosure Number: IPCOM000109254D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 2 page(s) / 59K

Publishing Venue

IBM

Related People

Kosuge, O: AUTHOR [+3]

Abstract

Disclosed is a write protection algorithm for a small size hard disk drive of which a servo system is the sector servo.

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

Write Protection Algorithm for Sector Servo System

       Disclosed is a write protection algorithm for a small
size hard disk drive of which a servo system is the sector servo.

      Usually in this servo system, the decision parameter for a data
writing is the variations of the servo position error signal. It
means the distance from the track center and is called PES.  Thus, at
the data writing, the PES which is at the forefront of the objective
sector, is checked, and if it meets some criteria, the data writing
is performed.

      In the new algorithm, the PES check is performed at both
forefront and rear ends of the objective sector.  By adding sector
rear end PES check, off-track writing is prevented.  The off-track
writing is that the head position from track center exceeds the
writing zone, and its cause is a head actuator resonance or external
impulsive force.

      The figure shows the write protection algorithm in more detail.
In this figure, from Sector-1 to Sector-4 are the write objective
sectors.  In the new method, the head off-track at the later half of
sector-3 can be checked by checking PES at both forefront and rear
ends of the objective sector.