Magnetic hard disk drive

• US 7,184,236 B2
• Filed: 09/21/2004
• Issued: 02/27/2007
• Est. Priority Date: 11/20/2000
• Status: Expired due to Fees

• Current Assignee: Hitachi Global Storage Technologies Japan Limited (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Japan Limited (Western Digital Corporation)
• Inventors: Ichihara, Takayuki, Takano, Hisashi, Akagi, Kyo, Hamaguchi, Takehiko
• Primary Examiner(s): Wellington; Andrea
• Assistant Examiner(s): Rodriguez; Glenda P.
• Application Number:
  US10/944,845
• Publication Number:
  US 20050036226A1
• Time in Patent Office: 889 Days
• Field of Search: None
• US Class Current: 360/60
• CPC Class Codes: G11B 20/10 Digital recording or reproducing
• CPC Class Codes: G11B 20/1252 for discontinuous data, e.g. digital information signals, computer programme data
• CPC Class Codes: G11B 2020/1232 sector, i.e. the minimal addressable physical data unit
• CPC Class Codes: G11B 2020/1238 track, i.e. the entire a spirally or concentrically arranged path on which the recording marks are located
• CPC Class Codes: G11B 2020/1267 Address data
• CPC Class Codes: G11B 2020/1287 Synchronisation pattern, e.g. VCO fields
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 2220/2516 Hard disks
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/5582 system adaptation for working during or after external perturbation, e.g. in the presence of a mechanical oscillation caused by a shock
• CPC Class Codes: G11B 5/59611 Detection or processing of peak/envelop signals
• CPC Class Codes: G11B 5/59655 Sector, sample or burst servo format
• CPC Class Codes: G11B 5/59694 System adaptation for working during or after external perturbation, e.g. in the presence of a mechanical oscillation caused by a shock

Abstract

A hard disk drive and magnetic medium including a servo area, a data area divided into a plurality of sector blocks and at least one micro-servo area disposed between two sector blocks. There may be a micro-servo area immediately preceding each of the plurality of sector blocks. The micro-servo areas include an address mark and a track parity check code that allow the detection of an external shock that causes the recording (write) head to skip to an adjacent track in the hard disk medium. The micro-servo area is smaller than the servo areas, and various numbers of different track parity check codes can be used for different resolution of shock detection. An acceleration sensor may also be provided to detect larger external shocks. By detecting various external shocks with improved accuracy, and aborting the recording operation of data if an external shock is detected, the corruption of data in adjacent tracks is substantially reduced to improve disk drive performance.

Claims

1. A magnetic hard disk drive comprising:

a magnetic hard disk comprising servo areas and data areas divided into a plurality of sector blocks,

a magnetic head comprising a reproducing element and a recording element, and

a data processing circuit for processing magnetic information input or output from the magnetic head,

wherein the data area have at least one micro-servo area comprising IDAM field and a parity code field, formed between at least two of said plurality of sector blocks,

the data processing circuit has an IDAM detector, a memory for a parity code, and comparator that compares a parity code, and comparator that compares a parity code of a target recording track with the parity code in the memory, and

a HDC that output the parity code of a target recording track to the comparator.

2. A magnetic hard disk drive according to claim 1, wherein the HDC shifts to the comparison of the parity code of a target recording track and the parity code in the memory involving disk rotation waiting, in case that they are not matched with each other.