Nelson Te Cheng

6697203, Feb 24, 2004

May 24, 2000

09/578262

Nelson Cheng - Fremont CA
Bill Higgins - Palo Alto CA
Hai Nguy - San Jose CA
Steven Stupp - Mountain View CA
Steven Lambert - San Jose CA

Maxtor Corporation - Milpitas CA

G11B 2736

360 31, 360 53

A method and apparatus for determining a lifetime for a medium to fail due to thermal decay of a magnetization pattern is provided. Different stress magnetic fields are applied to a write head for writing to a machine-readable medium resulting in a magnetic field on the medium. A time to failure, corresponding to each of the different stress magnetic fields, is determined, the time to failure being an amount of time for an amplitude of a signal on the medium to degrade beyond a predetermined failure criteria. A time to failure without a stress magnetic field is determined based on the corresponding times to failure determined for each of the different stress currents.

6751039, Jun 15, 2004

Nov 3, 2001

10/008317

Nelson Shih-Cheng Cheng - Fremont CA
Caleb Kai-Lo Chang - Sunnyvale CA
Steven Lambert - San Jose CA
Tue Thanh Ngo - Milpitas CA

Maxtor Corporation - Longmont CO

G11B 503

360 66, 360 31

A method of controlling bias supply sources for magneto-resistive transducer (MR) heads to provide essentially the same predetermined lifetime for the MR heads, by determining dependence of head lifetime on bias supply level and on head stripe temperature, and setting a bias supply level for each head based on said dependence of lifetime on bias supply level and on head temperature, to provide essentially the same predetermined lifetime for the heads.

7567400, Jul 28, 2009

Apr 27, 2005

11/117258

Nelson Cheng - Fremont CA, US

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

G11B 15/04

360 60, 360 31, 360 7702

An apparatus and method for improving the error rate of track information on a magnetic storage device is disclosed. One embodiment provides a counter for counting the number of writes to a first track on a magnetic storage device. In addition, a re-read and re-write initiator is provided for reading information from a second track adjacent to the first track and re-writing the information read from the second track back to said magnetic storage device when said counter reaches a pre-defined number of writes for the fist track.

7920359, Apr 5, 2011

Jan 31, 2008

12/012241

Yohji Maruyama - Saitama, JP
Nelson Cheng - Fremont CA, US
Hideki Zaitsu - Kanagawa, JP
Hisao Okamoto - Shizuoka, JP

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

G11B 5/127

3601253

Embodiments of the present invention achieve a high linear recording density and a high track recording density to thereby improve the areal recording density in a perpendicular magnetic recording apparatus having a magnetic head that includes a trailing shield and side shields around a main magnetic pole piece. According to one embodiment, in a magnetic recording apparatus, each of magnetic distances of various sorts is set so as to satisfy relationships of Lmag

8169730, May 1, 2012

Dec 17, 2009

12/641292

Nelson Cheng - Fremont CA, US
Lakshmi Ramamoorthy - San Jose CA, US
Kris Schouterden - San Jose CA, US
Masayoshi Shimokoshi - Kanagawa, JP

Hitachi Global Storage Technologies, Netherlands, B.V. - Amsterdam

G11B 5/02

360 55

A hard disk drive (HDD) comprising a magnetic disk that includes a data storage surface and an external magnetic field parallel to the data storage surface for suppressing track interference.

6445527, Sep 3, 2002

Jan 27, 1999

09/239037

Nelson Cheng - Fremont CA

Maxtor Corporation - Longmont CO

G11B 1518

360 69, 360 66, 360 31, 360 62

Multi-head disk drive system measures head resistances and selects lowest-resistance heads for track-servo operation during sleep mode, thereby substantially prolonging EM lifetime, improving field failure rate, unit production costs, and drive performance and yields.