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Positioning Error Signal Decoding Method for Magneto Resistive Head

IP.com Disclosure Number: IPCOM000114303D
Original Publication Date: 1994-Dec-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Kisaka, M: AUTHOR [+4]

Abstract

This article describes the method of decoding Positioning Error Signal (PES) of a hard disk drive using read/write head which has the offset between read and write head element such as Magneto Resistive (MR) head.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 62% of the total text.

Positioning Error Signal Decoding Method for Magneto Resistive Head

      This article describes the method of decoding Positioning Error
Signal (PES) of a hard disk drive using read/write head which has the
offset between read and write head element such as Magneto Resistive
(MR) head.

      If read head width is getting narrower, positioning dynamic
range is also narrower from the track center.  On the other hand,
written data pattern should be read by the narrow read head at the
offset position.

      The purpose of this method is to expand the positioning dynamic
range (radial direction) of the narrow read head properly within the
data track to read the written data at the offset position.

The following 1 and 2 summarize this method.
  1.  Positioning error signal decoding method is selected in the
       following cases;
      if the current position of the read head is:
        Case     Read Head Position        Decoding Method
        case A.  around the track center        ( W )
        case B.  outer of the track center      ( Z )
        case C.  inner of the track center      ( Y )
  2.  In the above method 1, positioning error signal decoding method
       is selected in case if the current read head positiong is in
some
       range from the track center, the selection depends on the
       following cases;
      if the target position of the read hea...