Browse Prior Art Database

Track 0 Search on Servo Track Writer

IP.com Disclosure Number: IPCOM000112517D
Original Publication Date: 1994-May-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Iwata, K: AUTHOR [+4]

Abstract

This article describes one method to define track 0 position when Servo Pattern Writing is started for Hard Disk Drive. The defined position, that is positioner's count, is memorized in Servo Track Writer (STW).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 84% of the total text.

Track 0 Search on Servo Track Writer

      This article describes one method to define track 0 position
when Servo Pattern Writing is started for Hard Disk Drive.  The
defined position, that is positioner's count, is memorized in Servo
Track Writer (STW).

      This article is based upon the apparatus which uses capacitance
probe to push the actuator of heads with non-contact method by using
gap servo as shown in Fig. 1.  This gap servo works to keep constant
gap by 100um after being free from crash stop.  Initially capacitance
probe mounted on Positioner is settled farther than 150 um due to
crash stop, therefore gap servo shows error -10v as shown in Fig. 2
As capacitance probe comes to 100um, error becomes near 0v.  The
error 0v means just touch point between actuator and crash stop where
is mechanically defined as track 0.  Error 0v is easily detected with
comparator.  At this point, its count of positioner is memorized in
STW.

      This method is superior to current technology, that is, data is
written once at crash stop and being read repeatedly until read error
occurs while head moves from the crash stop position by positioner
which contact to the actuator and pushes it.  Because following
concerns are solved.  1) Current technology rejects the file if a
defect exists around the track 0 even though one defect should not be
the reason of the file rejected.  2) The possibility of "track 0 not
found" error exists because VCM bias current toward p...