Yoo Mi Kim

6493173, Dec 10, 2002

Nov 8, 1999

09/436930

Yoo H. Kim - Laguna Niguel CA
Hanan Kupferman - Diamond Bar CA

Western Digital Technologies, Inc. - Lake Forest CA

G11B 1546

360 7704

A disk drive is disclosed comprising a track recorded on a disk, wherein the track has repeatable runout (RRO). The track comprises a plurality of embedded servo sectors including servo information stored at a servo data rate, and a plurality of data sectors between the embedded servo sectors. The track is headerless in that the plurality of data sectors are uninterrupted by sector identification data. One of the plurality of data sectors includes a RRO correction value used to compensate for the RRO, the RRO correction value being stored at a user data rate different than the servo data rate. The disk drive further comprises a head and a voice coil motor (VCM) for positioning the head over the track. A servo control system, responsive to the servo information and the RRO correction value, generates a VCM control signal that is applied to the VCM for positioning the head over the track.

6525892, Feb 25, 2003

Jan 28, 2000

09/493751

Gary L. Dunbar - Gilroy CA
Yoo H. Kim - Laguna Niguel CA
Hanan Kupferman - Diamond Bar CA
Brian Tanner - San Jose CA
David P. Turner - Los Gatos CA

Western Digital Technologies, Inc. - Lake Forest CA

G11B 2736

360 31, 360 46, 360 68, 360 75

A method of calibrating a write current-setting for writing servo sectors onto a recording surface through a head in a head disk assembly of a disk drive is disclosed. A preamplifier circuit has an input for receiving a selected control signal set by a current-setting value, the preamplifier circuit causing current to flow through the head with a current magnitude determined by the current-setting value. A multiple-pass process is performed in which a series of current-setting values are set for the control signal for generating a plurality of quality metrics each indicative of a quality of the selected control signal. Each pass in the multiple-pass process includes the steps of providing a data sequence to the preamplifier circuit to cause a test pattern to be written to the recording surface, and reading the test pattern and generating and storing at least one of the plurality of quality metrics. The generated and stored quality metrics are then evaluated to select a current-setting value for the selected control signal. The selected current-setting value is then set for the head, and the servo sectors are written onto the recording surface through the head.

6545830, Apr 8, 2003

Apr 30, 2001

09/846805

Albert W. Briggs - Newport Beach CA
Phat T. Nguyen - Laguna Niguel CA
Yoo H. Kim - Laguna Niguel CA

Western Digital Technologies, Inc. - Lake Forest CA

G11B 2736

360 31, 360 48, 360 7708, 360 7814

A disk drive is disclosed comprising a disk having a plurality of tracks including a plurality of data tracks and a plurality of reserved tracks. A plurality of embedded servo sectors are dispersed circumferentially around the tracks, the tracks are banded together to form a plurality of zones, each data track comprises a plurality of data sectors each having a first number of bits for storing user data, and each reserved track comprises calibration sectors each having a second number of bits for storing a calibration test pattern, wherein the second number of bits is greater than the first number of bits.

6545835, Apr 8, 2003

Aug 31, 2000

09/652857

Raffi Codilian - Irvine CA
Hanan Kupferman - Diamond Bar CA
Yoo H. Kim - Laguna Niguel CA

Western Digital Technologies, Inc. - Lake Forest CA

G11B 5596

360 7704, 360 7702

The present invention may be embodied in a method, and related apparatus, for determining a repeatable runout (RRO) compensation value set for a track on a disk in a disk drive, wherein the disk drive is initially manufactured and then shipped for installation in a host system. The track comprises a plurality of embedded servo sectors that define a circumferential path having RRO which requires compensation during track following. The method comprises determining a first RRO compensation value set for the track to a first desired learning level by measuring the RRO for the track based on a first predetermined number of disk rotations during the initial manufacturing of the disk drive. Then, after the disk drive is shipped for installation in the host system, determining a second RRO compensation value set for the track to a second desired learning level by measuring the RRO for the track based on at least a second predetermined number of disk rotations, wherein the second predetermined number of disk rotations is greater than the first predetermined number of disk rotations. The learning technique of the invention allows the disk drive to be shipped for installation in a host system with a portion of its tracks having little or no RRO compensation. After shipment, the disk drive may continue to improve the RRO compensation until all of the tracks have been optimally compensated.

6611393, Aug 26, 2003

Apr 30, 2001

09/846043

Phat T. Nguyen - Laguna Niguel CA
Yoo H. Kim - Laguna Niguel CA
Albert W. Briggs - Newport Beach CA

Western Digital Technologies, Inc. - Lake Forest CA

G11B 509

360 53, 360 69, 360 31

A disk drive is disclosed which calibrates at least one zone parameter in the field. During an active state of the disk drive, read errors are detected and corresponding entries are stored in an error list. During an off-line state, the error list is processed in order to calibrate at least one zone parameter.

6687078, Feb 3, 2004

Feb 28, 2001

09/797547

Yoo H. Kim - Laguna Niguel CA

Western Digital Technologies, Inc. - Lake Forest CA

G11B 5596

360 7704, 360 7708, 360 7804

The present invention may be regarded as a disk drive comprising a disk having a plurality of data tracks and at least one reserved track. At least one of the data tracks for recording user data along a circumferential path offset from the centerline of the data track, and the at least one reserved track for recording data track micro-jog values along a circumferential path substantially aligned with the centerline of the reserved track.

6690523, Feb 10, 2004

Apr 30, 2001

09/846075

Phat T. Nguyen - Laguna Niguel CA
Yoo H. Kim - Laguna Niguel CA
Albert W. Briggs - Newport Beach CA

Western Digital Technologies, Inc. - Lake Forest CA

G11B 2736

360 31

A disk drive is disclosed which calibrates at least one zone parameter in the field. During an off-line state of the disk drive, at least one of the adapted zone parameters is calibrated. During an active state of the disk drive, a read error is detected and a data-recovery firmware procedure is executed using adapted zone parameters in an attempt to recover data associated with the read error. If the data is successfully recovered from the data sector using the data-recovery firmware procedure, an adapted zone parameter counter is incremented and the operating zone parameters are updated with the adapted zone parameters if the adapted zone parameter counter exceeds a predetermined threshold.

20050244800, Nov 3, 2005

Feb 9, 2005

10/906228

Yoo Seung Kim - Los Angeles CA, US
Jennifer Kim - Los Angeles CA, US

G09B019/00

434245000

A portable virtual personality cultivation device to aid the teachings of the various religious scripts. The inventive device includes an input and output device as well as display device to alert the user of the processed information, i.e. quantified value of person's character based on various religious teachings. The device can be a hardware by itself or be installed as a part of various portable devices. The device can also be installed internally as a computer software.