公开(公告)号：JPH0737216A

公开(公告)日：1995-02-07

申请号：JP15500793

申请日：1993-06-25

Applicant: IBM

Inventor： KIGAMI YUJI ,  MATSUI TAKAO ,  KURACHI KOJI ,  OSAWA TOYOZO

IPC: G11B5/09 ,  G11B5/48 ,  G11B20/12 ,  G11B27/30

Abstract: PURPOSE: To improve a reading error rate on identification(ID) information in a sector servo type magnetic disk device provided with a head having a separated reading element and writing element. CONSTITUTION: One pair of ID fields 21a and 21b for recording ID information are set in each sector of each track of the magnetic disk. This one pair of ID fields are mutually separated in the direction along the track and radially deviated each other by the distance equivalent to the radial direction offset between the reading element 24 and writing element 23 related to the track. The magnetic head is positioned so as to read ID information in the ID field 21b with the reading element 23 at the time of a data writing operation on an optional track. The head is positioned so as to read ID information in the ID field 21a with the reading element 23 at the time of a data reading operation on the track.

公开(公告)号：JP2000123492A

公开(公告)日：2000-04-28

申请号：JP29095798

申请日：1998-10-13

Applicant: IBM

Inventor： OSAWA TOYOZO ,  KOBAYASHI KEIJI ,  KOWA TSUGUAKI ,  HASHIMOTO SATOSHI

IPC: G11B20/12 ,  G11B5/012 ,  G11B5/09 ,  G11B19/02

Abstract: PROBLEM TO BE SOLVED: To provide a disk type recording medium, a disk drive device, and the like that yield can be improved, complexness of control can be reduced, and reduction of performance can be suppressed. SOLUTION: Recording line density of a recording plane (e.g. 1c) of which a software error rate(SER) is bad is reduced, and recording line density of recording planes (e.g. 1a, 1b, 1d, 1e, 1f) of which SER is not so bad is increased. A control section 4e or a control section 5a changes a table in accordance with recording line density of each recording plane 1a-1f at the time of recording and reproducing, and changes recording and reproducing characteristics.