Michael F Moser

US Patent:

6754025, Jun 22, 2004

Filed:

Jan 12, 2000

Appl. No.:

09/482157

Inventors:

Stanley H. Shepherd - Morgan Hill CA
Michael Anthony Moser - San Jose CA
Yakov Lifchits - San Jose CA
Mohamad A. Rezvani - San Jose CA

Assignee:

Maxtor Corporation - Longmont CO

International Classification:

G11B 1546

US Classification:

360 7303, 360 7708, 360 51

Abstract:

A spindle motor control for a disk drive including a spindle motor for rotating a data disk at a desired rotational speed, and a data transducer head positionable relative to selected ones of a multiplicity of concentric data tracks formed on a data storage surface of the data disk by a head position actuator structure operating within a head position servo loop, wherein the concentric data tracks are periodically interrupted by a plurality of servo sectors per rotation, each servo sector recorded with head position information. The spindle motor control includes: a servo detector for detecting the head position information in at least one servo sector on a selected track under the transducer head in relation to a timing signal at a reference frequency; a position detector for determining the circumferential position of the detected head position information on the selected track in relation to the timing signal; and a controller for controlling the rotational speed of the spindle motor as a function of said circumferential position, to regulate the circumferential position of the transducer in relation to the servo sectors on the data tracks.

US Patent:

7199956, Apr 3, 2007

Filed:

Sep 20, 2002

Appl. No.:

10/251270

Inventors:

Michael Anthony Moser - San Jose CA, US
Ara Patapoutian - Westborough MA, US
John McEwen, legal representative - Porter TX, US
Bin Liu - Newark CA, US
Bruce Buch - Westborough MA, US

Assignee:

Maxtor Corporation - Scotts Valley CA

International Classification:

G11B 5/00
G11B 5/09
G11B 20/10
G11B 5/02
G11B 21/02
G11B 5/596

US Classification:

360 46, 360 32, 360 39, 360 67, 360 75, 360 7705

Abstract:

Disk drive self-servo writing includes transferring a reference pattern by magnetic printing onto a reference disk, wherein the resulting printed reference pattern includes embedded servo information that provides servo timing and head position information, installing the reference disk and a head into the disk drive, reading the printed reference pattern using the head to generate a readback signal, sampling the readback signal at a sampling rate to generate a sampled signal, processing the sampled signal waveform spectrum to generate a recovered signal including the embedded servo information and fundamental and higher harmonics of the sampled signal, using the embedded servo information from the recovered signal to precisely position and maintain the head at concentric tracks of the reference disk, and self-writing servo patterns onto the tracks with the head.

US Patent:

7209314, Apr 24, 2007

Filed:

Jun 9, 2005

Appl. No.:

11/148752

Inventors:

Zvonimir Z. Bandic - San Jose CA, US
Michael A. Moser - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/596

US Classification:

360 7804, 360 7708

Abstract:

A magnetic recording disk drive uses a phase-quadrature position-error-signal (PES) pattern and a servo signal demodulator that is insensitive to clock errors and phase-misalignment errors. The disk has angularly-spaced servo sectors, with each servo sector having radially-spaced servo tracks that contain a phase-quadrature pattern of servo blocks. A first band in each servo sector contains two generally like patterns radially-spaced in the servo track with the second pattern phase-shifted 90 degrees along-the-track from the first pattern. A second band in each servo sector is spaced along-the-track from the first band and also has two patterns like those in the first band, but with the phase shift of the second pattern being in the opposite direction to the phase shift of the second pattern in the first band. The demodulator calculates the true amplitudes of the servo signal from the measured amplitudes of the servo signals from each band to thereby remove clock errors and phase-misalignment errors.

US Patent:

7309967, Dec 18, 2007

Filed:

Mar 31, 2004

Appl. No.:

10/816588

Inventors:

Michael A. Moser - San Jose CA, US
Bryan S. Rowan - San Jose CA, US
Mantle Yu - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

H02P 3/14
H02P 3/18

US Classification:

318376

Abstract:

During normal operation of a hard disk drive, control logic controls a plurality of switching elements to provide electrical power to a spindle motor and head motor of the disk drive from a voltage source coupled to first and second voltage supply nodes (e. g. , Vcc and ground), the spindle motor has a set of motor windings to which the electric power is applied to rotate the spindle motor, and the control logic is configured to enter a regenerative braking state during normal operation where the switching elements are controlled to isolate the spindle motor from the first voltage supply node and cause regenerative braking of the spindle motor so that kinetic energy due to rotation of the spindle motor is converted to electrical power that is supplied to the head motor by virtue of inductance of one or more motor windings in the set.

US Patent:

7508618, Mar 24, 2009

Filed:

Dec 27, 2007

Appl. No.:

11/965637

Inventors:

Gary A. Herbst - San Jose CA, US
Bernhard E. Knigge - San Jose CA, US
Michael A. Moser - San Jose CA, US
Bruce A. Wilson - San Jose CA, US

International Classification:

G11B 21/02
G11B 27/36

US Classification:

360 75, 360 31

Abstract:

Magnetic disk drive systems and associated methods are described for precisely detecting contact of read/write elements of a recording head with a magnetic disk due to increasing a heating power applied to heating elements in the recording head. Contact is detected based on adjusted timing signals which are generated by measuring the current applied to a spindle motor, and generating an estimated timing signal from the measured motor current for increments of the heating power. An actual servo timing signal is simultaneously measured from servo fields on the magnetic disk, and the adjusted timing signals are calculated based on the difference between the estimated timing signal and the servo timing signal. Multivariate statistical analysis may also be performed on the adjusted timing signals and other contact indicative variables (such as off-track and slider vertical bouncing) to generate a likelihood of contact at the increments of the heating power.

US Patent:

7675703, Mar 9, 2010

Filed:

Jun 8, 2007

Appl. No.:

11/759959

Inventors:

Thomas R. Albrecht - San Jose CA, US
David Timothy Flynn - Mantorville MN, US
Richard Leo Galbraith - Rochester MN, US
Michael Anthony Moser - San Jose CA, US
Bruce Alexander Wilson - San Jose CA, US
Xiao Z. Wu - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/09

US Classification:

360 51

Abstract:

A system and method accurately clocks write data to the discrete data blocks in a patterned media disk drive. The precise time intervals between successive timing marks in the data tracks are measured by a timing mark detector that counts the integer number of write clock cycles between successive timing marks and the fractional part of a write clock cycle by detecting the phase difference between a timing mark and a reference signal. The resulting timing error is output to a write clock compensator. The write clock is capable of generating equally spaced primary phases and phases intermediate the primary phases. The compensator includes a phase rotator that controls which write clock phase is selected for output. The value in a phase register of the compensator is used to control the phase rotator to advance or retard the write clock phase, and thus to adjust its frequency and phase so as to be synchronized for writing to the data blocks.

US Patent:

7782561, Aug 24, 2010

Filed:

Feb 28, 2007

Appl. No.:

11/680398

Inventors:

Thomas R. Albrecht - San Jose CA, US
Michael A. Moser - San Jose CA, US
Manfred Ernst Schabes - Saratoga CA, US
Xiao Z. Wu - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/09

US Classification:

360 48

Abstract:

A patterned magnetic recording medium has discrete data islands arranged in spaced-apart tracks, with the tracks being arranged in multi-track groups or “hypertracks”. The islands have an equal island-spacing (IS) distance in the along-the-track direction and within each hypertrack the tracks are spaced-apart an equal track-spacing (TS) distance. If there are N tracks in a hypertrack then the islands in each track of a hypertrack are shifted in the along-the-track direction by 1/N times IS from the islands in adjacent tracks in the same hypertrack. The read and write heads have a lateral or cross-track width generally equal to the cross-track width of a hypertrack, so the read and write heads span all the individual tracks in a hypertrack. The hypertracks are spaced apart cross-track direction by a group-spacing (GS) distance, with GS being greater than TS. The islands in a hypertrack may be shifted in the along-the-track direction by approximately N times IS from the islands in adjacent hypertracks.

US Patent:

7848039, Dec 7, 2010

Filed:

Aug 11, 2007

Appl. No.:

11/837503

Inventors:

Michael A. Moser - San Jose CA, US
Satoshi Yamamoto - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G11B 5/09

US Classification:

360 48, 360 53, 360 7702, 360 7804

Abstract:

A magnetic recording disk drive uses a disk having pre-patterned servo sectors extending generally radially across the data tracks. The servo sectors include at least two position error signal (PES) bursts or fields. The phases of the PES fields in the servo readback signal are demodulated to generate a PES to control the disk drive actuator for positioning the read/write heads. Each field contains generally radially directed magnetized stripes, with each stripe comprising a plurality of islands forming a zigzag pattern. The stripes have alternating polarity of magnetizations in the along-the-track direction. In one implementation there are four fields: a first pair of fields A and B wherein the zigzag pattern of the radial stripes in field A is the mirror image about a radial line of the zigzag pattern of the radial stripes in field B, and a second like pair of fields C and D, but wherein the radial stripes in fields C and D are shifted radially by one-half the island radial height from the radial stripes in fields A and B.