Browse Prior Art Database

Sector Servo using Patterned Magnetic Media Blocks Written with Magnetic Transitions

IP.com Disclosure Number: IPCOM000103817D
Original Publication Date: 1993-Feb-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Hetzler, SR: AUTHOR [+2]

Abstract

The invention disclosed is magnetic recording disk such as that described in [*], but having a position error signal (PES) with increased signal amplitude.

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

Sector Servo using Patterned Magnetic Media Blocks Written with Magnetic Transitions

      The invention disclosed is magnetic recording disk such as that
described in [*], but having a position error signal (PES) with
increased signal amplitude.

      The magnetic media is patterned with discrete magnetic tracks
rather than a continuous magnetic surface.  Discrete servo blocks and
gray-code track identifying fields are also patterned onto the disk,
for sector servo information.  The patterns are formed during
fabrication of the disk.

      In the prior art, the radial location of the servo data was
determined by patterning the disk, and the signal encoding was
accomplished magnetically.  Servo blocks were exposed to a magnetic
field generated by passing a DC current through a recording head.
Each servo block became magnetized in a circumferential direction,
thus presenting two discrete magnetic transitions to a passing head.
Since the tracks were accurately positioned radially by lithography,
the noise problems associated with track offsetting were
substantially eliminated.

      Similarly, the proposed invention patterns tracks and encodes
signals magnetically.  But rather than trying to pattern the actual
servo bits, A-B servo burst patterns are written as follows.  A data
head referenced to a clock track prewrites the entire disk with a
predetermined data pattern t the servo data rate.  This pattern
writes common burst patterns to the A and B se...