Browse Prior Art Database

Adaptive Track Per Inch

IP.com Disclosure Number: IPCOM000114278D
Original Publication Date: 1994-Dec-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 2 page(s) / 64K

Publishing Venue

IBM

Related People

Hashimoto, S: AUTHOR [+3]

Abstract

Disclosed is a technique for increasing capacity of Hard Disk Drive (HDD) using current magnetic recording technology. Advantage of this technique is that it prevents from insufficient usage of recoding media due to component process distribution.

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Adaptive Track Per Inch

      Disclosed is a technique for increasing capacity of Hard Disk
Drive (HDD) using current magnetic recording technology.  Advantage
of this technique is that it prevents from insufficient usage of
recoding media due to component process distribution.

      It can be possible by optimizing data track pitch on HDD which
uses sector servo technique.  It makes possible reducing effective
areal density with same capacity of HDD or increasing capacity
without increasing effective areal density.

      Fig. 1 shows required Bit Per Inch (BPI) at most inner data
track to realize same capacity of HDD.  For example, to realize 3500
Track Per Inch (TPI) using conventional technique, required BPI at
most inner data track is 40K for both maximum and minimum effective
track width head.  By using ADAPTIVE TPI technique, BPI can be
reduced to 35.3K from 40K with average effective track width head,
and 31.7K BPI with minimum effective track width head.

      Fig. 2 shows relation between effective magnetic areal density
and track pitch.  From this chart effective areal density of 3500 TPI
using conventional technique is
  - 193(Mb/sq-in) to 171(Mb/sq-in) average effective track width head
                                                     (11% reduction)
  - 239(Mb/sq-in) to 189(Mb/sq-in) minimum effective track width head
                                ...