Mark H Kryder

6531202, Mar 11, 2003

Nov 28, 2000

09/724112

Dmitri Litvinov - Pittsburgh PA
Sakhrat Khizroev - Pittsburgh PA
Mark Howard Kryder - Pittsburgh PA

Seagate Technology LLC - Scotts Valley CA

G11B 566

428 653, 428611, 428694 T, 428694 TM, 428900, 427128, 427131

The present invention provides perpendicular recording media having a soft magnetic underlayer and magnetic regions which generate an external magnetic field in the soft magnetic underlayer. The soft magnetic underlayer is brought into a substantially single-domain state by the magnetic field, thereby reducing or eliminating unwanted noise in the soft underlayer. In a preferred embodiment, the recording medium includes a ring-shaped soft magnetic underlayer positioned between concentric ring-shaped magnetic regions.

6771462, Aug 3, 2004

Sep 19, 2000

09/665598

Sakhrat Khizroev - Pittsburgh PA
Dmitri Litvinov - Pittsburgh PA
Mark H. Kryder - Bradfordwoods PA

Seagate Technology LLC - Scotts Valley CA

G11B 5187

360122

A perpendicular recording head for use with magnetic recording media includes a main pole having a concave tip. The concave tip focuses the magnetic flux from the main pole onto a smaller area of the magnetic recording medium than a conventional main pole when the main pole is at its flying height from the magnetic recording medium. Although the most preferred perpendicular recording head includes a concave cavity having an elliptical profile when viewed from the side, any substantially concave cavity may be used advantageously.

6865056, Mar 8, 2005

Oct 4, 2000

10/031320

Sakhrat Khizroev - Pittsburgh PA, US
Dmitri Litvinov - Pittsburgh PA, US
Mark Howard Kryder - Pittsburgh PA, US
James A. Bain - Pittsburgh PA, US

Seagate Technology LLC - Scotts Valley CA

G11B005/31

360119

A longitudinal recording head () for use with magnetic recording media includes a non-uniform gap () between first () and second magnetic () poles which focuses magnetic flux onto a small area of the magnetic recording medium. The non-uniform gap is preferably in the form of a cavity that is contoured to produce the desired flux pattern. Longitudinal recording heads incorporating the non-uniform gap are capable of improved recording densities.

7394622, Jul 1, 2008

Dec 7, 2004

11/005819

Edward Charles Gage - Mars PA, US
Gary Clark Rauch - Pleasanton CA, US
Rene Johannes Marinus van de Veerdonk - Wexford PA, US
Hans Juergen Richter - Palo Alto CA, US
Terry Wayne McDaniel - Volcano CA, US
Mark H. Kryder - Pittsburgh PA, US

Seagate Technology LLC - Scotts Valley CA

G11B 5/82

360135, 360133

A magnetic recording medium comprises a magnetically soft underlayer having a plurality of cavities in a surface thereof, and a magnetic recording material in the cavities, wherein a surface of the magnetic recording material in the cavities is substantially coplanar with the surface of the soft underlayer. A recording system that includes the recording medium is also included.

48887501, Dec 19, 1989

Nov 12, 1987

7/119116

Mark H. Kryder - Pittsburgh PA
Han-Ping D. Shieh - Pittsburgh PA

G11B 1112

369 13

Method and system for overwriting binary data values in microscopic storage regions of a thin film ferrimagnetic layer without using external magnetic bias aiding the recording process. The ferrimagnetic layer is selected having a compensation temperature at least a few tens of degrees above room temperature. In recording data, any previously recorded data is erased to establish a known state and magnetic domains of reverse magnetic polarity are recorded when the known state differs from the binary data state by temporarily heating an area on the ferrimagnetic layer above the compensation temperature in the absence of any external aiding magnetic bias.

46791809, Jul 7, 1987

Mar 7, 1986

6/837130

Mark H. Kryder - Allegheny PA
Han-Ping D. Shieh - Pittsburgh PA

General Electric Company - Schenectady NY

G11B 5024
G11B 509
G11B 1100

369 13

Methods for directly over-writing the binary data value of a bit of digital data, stored in a particular one of a multiplicity of microscopic storage regions of a thin-film magneto-optic recording layer, first locate the storage region and non-destructively read the stored data value therefrom, and then compare the recovered value against the data value of an information bit to be stored in the same storage region. If the comparison indicates that no change in the stored data value is required, then the process proceeds to read and compare the next bit of data, from the next associated storage location. If the comparison indicates that a reversal of the magnetic moment of that region is required to store the new data value, a source of energy is energized to heat the particular storage region of a sufficiently high temperature that the self-demagnetization field of the recording layer material inverts the net magnetic moment of that region. Multiple over-writing of the long-term stable stored data values can be provided.

58636617, Jan 26, 1999

Apr 17, 1996

8/634051

Xiaoyu Sui - Pittsburgh PA
James A. Bain - Pittsburgh PA
Mark H. Kryder - Bradfordwoods PA

Carnegie Mellon University - Pittsburgh PA

G11B 566

428469

A method of making c-axis perpendicularly oriented barium hexaferrite thin films by the crystallization of amorphous barium hexaferrite on a platinum underlayer is provided. Using a thin underlayer of platinum, barium hexaferrite films can be deposited by conventional rf diode or magnetron sputtering. Such deposition may be performed at room temperature, after which excellent c-axis perpendicular orientation can be achieved by rapid ex-situ annealing. The c-axis perpendicular orientation can also be achieved through in-situ annealing.

51843358, Feb 2, 1993

May 10, 1991

7/700882

Mark H. Kryder - Allegheny PA
Han-Ping D. Shieh - Pittsburgh PA

Movid Information Technology, Inc. - Schenectady NY

G11B 1304
G11B 1110
G11B 1112

369 13

Methods for directly over-writing the binary data value of a bit of digital data, stored in a particular one of a multiplicity of microscopic storage regions of a thin-film magneto-optic recording layer, in the absence of a substantial externally applied bias magnetic field, employ a magnetic material having a compensation temperature a few tens of degrees centigrade above room temperature. A source of energy is energized to heat the particular storage region to a sufficiently high temperature that the self-demagnetization field of the recording layer material inverts the net magnetic moment of that region. Multiple over-writing of the long-term stable stored data values can be provided.