IP Library Granted Patent US 7,986,486
Granted Patent B2
US 7,986,486 · App. 12/470,460 · Granted Jul 26, 2011

Hard-disk drive, method of controlling the hard-disk drive, and method of manufacturing the hard-disk drive

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Quick Facts
Patent No.
US 7,986,486
App. No.
12/470,460
Granted
Jul 26, 2011
Kind
B2
Abstract

A hard-disk drive. The hard-disk drive includes a magnetic-recording disk having a plurality of tracks formed thereon. The hard-disk drive also includes a magnetic-recording head configured to be positioned over a target track selected from the plurality of tracks and configured to write data to and to read data from the target track. Moreover, the hard-disk drive includes a range-definer configured to define an allowed range of a position error of the magnetic-recording head corresponding to the target track. In addition, the hard-disk drive includes a write-enabler configured to determine whether writing data by the magnetic-recording head is allowed based on the position error of the magnetic-recording head with respect to the target track and the allowed range that is calculated from data read out by the magnetic-recording head.

Claims (19)

1. A hard-disk drive comprising:

a magnetic-recording disk having a plurality of tracks formed on at least one side thereof;

a magnetic-recording head configured to be positioned over a target track selected from said plurality of tracks formed on a same side of said magnetic-recording disk and configured to write data to and to read data from said target track;

a range-definer configured to define an allowed range of a position error of said magnetic-recording head corresponding to a track pitch of said target track; and

a write-enabler configured to determine whether writing data by said magnetic-recording head is allowed based on said position error of said magnetic-recording head with respect to said target track and said allowed range corresponding to said track pitch that is calculated from data read out by said magnetic-recording head.

2. The hard-disk drive according to claim 1 , wherein

said range-definer obtains said track pitch at said target track based on each of said track pitches of said plurality of tracks evaluated in advance and defines said allowed range in accordance with said track pitch.

3. The hard-disk drive according to claim 2 , further comprising a memory configured to store a table representing a relationship between said each track and said track pitch prepared by evaluating each of said track pitches of said plurality of tracks in advance, wherein

said range-definer reads out from said table said track pitch at said target track.

4. The hard-disk drive according to claim 2 , wherein

said range-definer obtains said track pitch at said target track from an equation representing a relationship between said each track and said track pitch prepared by evaluating each of said track pitches of said plurality of tracks in advance.

5. The hard-disk drive according to claim 1 , wherein

said range-definer obtains said track pitch at said target track based on said track pitches of said plurality of tracks corresponding to said radial positions of said magnetic-recording disk evaluated in advance and defines said allowed range in accordance with said track pitch.

6. A method of controlling a hard-disk drive, including a magnetic-recording disk having a plurality of tracks formed on at least one side thereof and a magnetic-recording head configured to be positioned over a target track selected from said plurality of tracks and configured to write data to and to read data from said target track, said method comprising:

defining an allowed range of a position error of said magnetic-recording head corresponding to a track pitch of said target track selected from said plurality of tracks formed on a same surface of said magnetic-recording disk; and

determining whether or not writing data by said magnetic-recording head is allowed based on said position error of said magnetic-recording head with respect to said target track and said allowed range that is calculated from data read out by said magnetic-recording head.

7. A method of manufacturing a hard-disk drive, including a magnetic-recording disk having a plurality of tracks formed on at least one side thereof and a magnetic-recording head configured to be positioned over a target track selected from said plurality of tracks and configured to write data to and to read data from said target track, said method comprising:

evaluating each of said track pitches of said plurality of tracks formed on at least one side of said magnetic-recording disk; and

storing data representing a relationship between said each track and said track pitch occurring on a same surface of said magnetic recording disk in a storage unit of said hard-disk drive.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 6, 2016
From: HGST NETHERLANDS B.V.
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 040826/0821 →
CHANGE OF NAME Recorded Oct 25, 2012
From: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
To: HGST NETHERLANDS B.V.
Reel/Frame 029341/0777 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 22, 2009
From: ABE, JIRO; UCHIDA, HIROSHI; UEDA, TETSUO
To: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
Reel/Frame 022725/0706 →