Mark D Schultz

US Patent:

6411453, Jun 25, 2002

Filed:

Sep 3, 1998

Appl. No.:

09/145930

Inventors:

Timothy Joseph Chainer - Mahopac NY
Mark Delorman Schultz - Elmsford NY
Edward John Yarmchuk - Mahopac NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 509

US Classification:

360 51, 360 75, 360 76

Abstract:

Off-track time shift estimates are determined and used in order to write subsequent trigger patterns on a storage medium at different track pitches. Various procedures for determining an off-track time shift estimate are provided. These procedures include measuring time intervals between a related set of trigger patterns and another trigger written on the storage medium; measuring time intervals between a motor index and a particular trigger pattern at two different radial locations; measuring the difference in the center location of two trigger patterns written at different radial locations; and microjogging a recording transducer during the interval between two different trigger patterns.

US Patent:

6429989, Aug 6, 2002

Filed:

Jun 13, 2000

Appl. No.:

09/592740

Inventors:

Mark D. Schultz - Elmsford NY
Bucknell C. Webb - Ossining NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 509

US Classification:

360 51, 360 7708, 360 7814

Abstract:

A method for writing timing marks on a rotatable storage medium, such as on a disk in a disk drive, includes the steps of: 1) during a rotation of the disk, detecting the passage of at least a portion of a first timing mark located at a radial trajectory at a first radius of the disk, and 2) during the same rotation of the disk, writing a second timing mark at a second radius of the disk. The second timing mark is located at least one of a) where at least a portion of the second timing mark overlaps at least a portion of the radial trajectory of the first timing mark, and b) where the second timing mark is in close proximity to the radial trajectory of the first timing mark. The second timing mark is written based on different parameters such as a measured time interval, a calculated time interval, and a predetermined delay.

US Patent:

6469859, Oct 22, 2002

Filed:

Nov 24, 1998

Appl. No.:

09/198730

Inventors:

Timothy Chainer - Mahopac NY
Mark Delorman Schultz - Elmsford NY
Bucknell Chapman Webb - Ossinging NY
Edward John Yarmchuk - Mahopac NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 2102

US Classification:

360 75

Abstract:

An accurate and time-efficient method and system for self-servowriting wherein at least one reference value used to position the transducer is updated for some, but not all, of the tracks to be written. The reference value(s) is dependent upon a predefined indicium of transducer position, such as the amplitude of the readback signal obtained from a written track when the transducer is positioned on the track. In a first embodiment, updating of the reference value(s) is performed at every Nth track written, where N is a fixed number or range of numbers determined by an expected track-to-track variation of the indicium. The servowriting system may be designed to dynamically increase or decrease N during servowriting in response to actual variations in the indicium. According to a second embodiment, updating is only performed when needed, e. g. when the variation of the measured indicium between two written tracks (not necessarily adjacent tracks) exceeds a predefined threshold value.

US Patent:

6476989, Nov 5, 2002

Filed:

May 3, 1999

Appl. No.:

09/304233

Inventors:

Timothy Chainer - Putnam Valley NY
Mark Delorman Schultz - Ossining NY
Bucknell Chapman Webb - Ossining NY
Edward John Yarmchuk - Mahopac NY

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 2736

US Classification:

360 31, 360 75, 360 53, 360 60, 360 7708, 360 7303

Abstract:

An improved servowriting system and method whereby errors introduced into the written servo information are reduced or eliminated for greater servowriting accuracy. Accuracy is enhanced by one or more of the following improvements: 1) optimizing write current and write frequency to minimize write width modulation; 2) optimizing the RPM of the storage medium to minimize random mechanical vibration; and 3) providing a clip level check to eliminate the introduction of large errors in product servopattern. The proposed improvements provide substantial rejection of, for example, mechanical and magnetic disturbances, ensuring a robust servowriting process.

US Patent:

6603627, Aug 5, 2003

Filed:

May 31, 2000

Appl. No.:

09/584302

Inventors:

Timothy Joseph Chainer - Mahopac NY
Mark Delorman Schultz - Elmsford NY
Edward John Yarmchuk - Somers NY

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 2102

US Classification:

360 75

Abstract:

A technique for self-servowriting a servopattern on a data storage medium is disclosed. An initial set of servopattern tracks is written by moving an actuator against a compliant structure (e. g. , crashstop) with a first force applied thereto to hold the actuator in a first position to write a first track of the servopattern. The force is changed, thereby reaching a second position of the actuator against the compliant structure, at which a second track of the servopattern is written. The process is iterated for additional tracks. The distances (i. e. , overlap) between pairs of written tracks are measured using a read element of the actuator, and this measured distance is compared to predetermined, desired distance. If the measured distance is within a specified tolerance, the process is complete; and if not, the tracks are erased and the process is repeated with changed forces applied to the actuator against the crashstop resulting in modified distances between tracks. The present invention overcomes the problem of self-servowriting an initial set of tracks of a servopattern, especially when the read element is separated from the write element in a direction along which the servowriting steps.

US Patent:

6611395, Aug 26, 2003

Filed:

Nov 3, 1999

Appl. No.:

09/432950

Inventors:

Timothy J. Chainer - Putnam Valley NY
Edward J. Yarmchuk - Somers NY
Mark D. Schultz - Elmsford NY
Bucknell C. Webb - Ossining NY

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 2102

US Classification:

360 75

Abstract:

A method for writing tracks on a rotating disk media data storage device comprising the steps of: receiving a set of component parameters; and adjusting track pitch for each of the tracks to be written in each disk according to the component parameters. According to another embodiment a disk drive includes at least one disk comprising a two or more of tracks in which the track pitch between each pair of adjacent tracks is set based on component parameters such as the recording head widths. According to another embodiment a servowriter is adapted to perform the method discussed above.

US Patent:

6633451, Oct 14, 2003

Filed:

Oct 25, 1999

Appl. No.:

09/426435

Inventors:

Timothy J. Chainer - Putnam Valley NY
Bucknell C. Webb - Ossining NY
Mark D. Schultz - Elmsford NY
Edward J. Yarmchuk - Somers NY

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 2102

US Classification:

360 75

Abstract:

A method is provided for writing a servo-pattern on a storage medium. According to the method, first timing marks are written at a first radial position of the storage medium, and the head is moved to a second radial position. Time intervals between selected pairs of the first timing marks are measured, and other timing marks are written at the second radial position of the storage medium. The measuring step is performed after the moving step. In one preferred method, the steps of moving, measuring, and writing other timing marks are repeated until the servo-pattern is written on an entire surface of the storage medium. A method is also provided for generating an initial aligned pattern of timing marks for self-servo-writing on a storage medium.

US Patent:

6687069, Feb 3, 2004

Filed:

Nov 6, 2001

Appl. No.:

09/992394

Inventors:

Timothy Joseph Chainer - Mahopac NY
Mark Delorman Schultz - Elmsford NY
Edward John Yarmchuk - Mahopac NY

Assignee:

Hitachi Global Technologies Netherlands, B.V. - Amsterdam

International Classification:

G11B 509

US Classification:

360 51, 360 75, 360 7708, 360 76

Abstract:

Off-track time shift estimates are determined and used in order to write subsequent trigger patterns on a storage medium at different track pitches. Various procedures for determining an off-track time shift estimate are provided. These procedures include measuring time intervals between a related set of trigger patterns and another trigger written on the storage medium; measuring time intervals between a motor index and a particular trigger pattern at two different radial locations; measuring the difference in the center location of two trigger patterns written at different radial locations; and microjogging a recording transducer during the interval between two different trigger patterns.