US 7,551,379 B2
Write element before read element with early servo termination on write
Mantle Yu, San Jose, Calif. (US); and Bernd Lamberts, Cupertino, Calif. (US)
Assigned to Hitachi Global Storage Technologies Netherlands B.V., Amsterdam (Netherlands)
Filed on Oct. 10, 2006, as Appl. No. 11/545,830.
Prior Publication US 2008/0084629 A1, Apr. 10, 2008
Int. Cl. G11B 5/09 (2006.01)
U.S. Cl. 360—51  [360/21; 360/62; 360/77.06] 22 Claims
OG exemplary drawing
 
1. A disk drive comprising:
a disk including a plurality of tracks each having a plurality of data sectors spaced by servo sectors, the disk configured to rotate in a circumferential direction of the tracks;
a magnetic head having a write element to write data to the tracks and a read element to read data from the tracks, the write element being disposed in front of the read element against the circumferential direction of rotation of the disk so that the write element goes over a location on a track before the read element; and
a processor configured to control the write element of the magnetic head in a write operation to write data to the data sector of a track until an end of the data sector before reaching a front end of a servo sector following the end of the data sector, to control the read element of the magnetic head to read information in the servo sector needed for the write operation, and to control the write element to start writing data in a next data sector following the servo sector after the write element reaches the next data sector and after the read element has read all information in the servo sector needed for the write operation;
wherein the write element is separated from the read element by a read/write separation gap;
wherein a write to read recovery is needed for disturbance to decay due to switching from write mode to read mode before the read element starts reading information in the servo sector after the write element stops writing in the data sector;
wherein the write to read recovery is larger than the read/write separation gap by a recovery difference; and
wherein the processor is configured to control the write element to stop writing before reaching the end of the data sector by a space from the end of the data sector which is equal to or larger than the recovery difference so as to allow time for disturbance to decay due to switching from write mode to read mode.