Khalil B Dizaji

6980386, Dec 27, 2005

Jun 4, 2003

10/453955

Joseph L Wach - Longmont CO, US
Khalil B Dizaji - Louisville CO, US

Seagate Technology LLC - Scotts Valley CA

G11B015/12

360 63, 360 48, 360 7808, 711 4, 711112

A disc drive has transducers supported by an actuator to fly proximate data tracks on surfaces of rotating information storage discs. Each of the discs is partitioned into concentric regions. A control system arranges the deposition of data in write operations to the tracks on the disc surfaces, as data is written to the discs, such that the data is sequentially organized both on the tracks and within each of the regions. The control system writes data from a track adjacent a first region boundary in a first direction to a second region boundary until all tracks in a region are full. The control system executes a head switch between adjacent surfaces of the discs. The write sequence is repeated in each adjacent region until all regions are full. The resulting trapezoidal serpentine pattern of actuator movement and head switches is repeated until all of the write operations are complete.

7177112, Feb 13, 2007

Apr 3, 2002

10/115384

Christopher Thomas Settje - Westminster CO, US
Khalil B. Dizaji - Louisville CO, US
Michael Edward Baum - Longmont CO, US
Rodney Brittner - Longmont CO, US

Seagate Technology LLC - Scotts Valley CA

G11B 5/596

360 7704

The present invention reduces the time required for coefficient convergence and thus improves time-to-ready. To that end, the present invention provides an initial learn—preferably non-zero—coefficient. The initial learn coefficient is based on a translation of timing information to position information. One aspect of the present invention uses address marks of a disc then translates them to phase position information. The present invention measures the times between address marks of adjacent servo sectors. Variations between those times is related is related to disc runout, particularly disc eccentricity. Also, the servo sectors are used to identify at which phase the maximum amplitude (or magnitude) of the timing variations occur. This phase information and maximum amplitude are used as variables in determining the initial learn coefficient. The present invention also utilizes a plant model to predetermine a variable.

20030112544, Jun 19, 2003

Jun 26, 2002

10/180569

Brent Jay Harmer - Johnstown CO, US
Jianbo He - Longmont CO, US
Khalil Dizaji - Louisville CO, US
Hai Ho - Broomfield CO, US
Reed Hanson - Chaska MN, US

G11B005/596

360/077020, 360/077040

Method and apparatus for more accurate track following. Control circuitry rotates a data storage surface containing thousands of annular tracks. A “measured” subset of the tracks is selected so as to be interspersed with an “unmeasured” subset. The calibration profile is derived based on position error signals each obtained by reading from the measured subset and not from the unmeasured subset. Data from the unmeasured subset of tracks is ignored, in generating and/or updating the profile.

20030161067, Aug 28, 2003

Jun 24, 2002

10/179153

Nicolai Ramler - Boulder CO, US
Christopher Settje - Westminster CO, US
Ewe Tan - Longmont CO, US
Khalil Dizaji - Louisville CO, US

Seagate Technlogy LLC

G11B005/596
G11B005/09
G11B015/12

360/077050, 360/051000, 360/063000

An embodiment of the present invention may be described as a method of determining a disc drive head position over a data surface during a head switch operation. The method includes switching from a first head located over a first data surface on one disc to a second head located over a second data surface on a different disc. Each data surface has non-index servo sectors interspersed between a plurality of index servo sectors defined thereon, and each index servo sector has a unique index code corresponding to its angular track position. The method also includes reading an index code from an index servo sector on the second surface and determining an index servo sector number from the index code. Additionally, the method includes incrementing the servo sector number as the second head encounters subsequent servo sectors. A disc drive includes data storage discs arranged in a disc stack. The disc drive is adapted to ascertain head position following a head switch between a first head positioned over a first data surface on one disc and a second head positioned over a second data surface on a different disc utilizing a plurality of index servo sectors defined on the second data surface.

20040156137, Aug 12, 2004

Apr 9, 2003

10/409821

Christopher Settje - Westminster CO, US
Khalil Dizaji - Louisville CO, US

G11B005/09
G11B005/596

360/051000, 360/077040

A method for determining the repeatable timing error in reclamped media is disclosed. The method allows the variation of the time intervals between servo sectors or other known locations on tracks on the disc to be determined and saved on the data storage device for later use in checking the timing during device operation. A second method for pulling write gate during data storage device operation based on known repeatable timing error data is also disclosed. This method checks the measured time intervals between sectors against an acceptable time interval range determined based on the known repeatable timing error for the disc.