Alexander M Taratorin

US Patent:

7126773, Oct 24, 2006

Filed:

Mar 30, 2005

Appl. No.:

11/093929

Inventors:

Alexander Taratorin - Sunnyvale CA, US

Assignee:

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

International Classification:

G11B 5/09
G11B 5/02

US Classification:

360 46, 360 68

Abstract:

A method is presented for precompensation of Non-Linear Transition Shift (NLTS) in magnetic recording media using a perpendicular recording write head. The method includes maintaining a count of non-transition data bits (“zeroes”) preceding a data transition (“one”) to be written. A precompensation value is assigned which correlates to the count of non-transition data bits preceding the data transition to be written. The assigned precompensation value is then applied to delay timing of a write signal sent to the perpendicular recording write head so that the location of the actual written data transition more closely aligns with an ideal location of the data transition to be written.

US Patent:

8080992, Dec 20, 2011

Filed:

Nov 15, 2007

Appl. No.:

11/940970

Inventors:

Alexander M. Taratorin - Sunnyvale CA, US

Assignee:

Infinitum Solutions, Inc. - Santa Clara CA

International Classification:

G01R 33/12

US Classification:

324210, 324228

Abstract:

A write head is tested by measuring the effect that magnetic fields have on the inductance of the write head. For example, a perpendicular write head may be placed in a magnetic field with a first angle, e. g. , non-parallel and non-perpendicular, to the air bearing surface and the inductance is measured. After altering the angle of the magnetic field the inductance is again tested. In another embodiment, the angles may be parallel and perpendicular to the air bearing surface. The difference in the inductance value can be used to determine a characteristic of the write head, such as the presence of a recording pole. In some embodiments, the inductance may be measured while applying a bias current to the write head while the write head is in an external magnetic field.

US Patent:

8289818, Oct 16, 2012

Filed:

Nov 16, 2011

Appl. No.:

13/298039

Inventors:

Alexander M. Taratorin - Palo Alto CA, US
Juergen Heidmann - Salinas CA, US

Assignee:

Infinitum Solutions, Inc. - Santa Clara CA

International Classification:

G11B 11/00

US Classification:

369 1313, 369 1301, 369 1332, 369 1333, 360 59

Abstract:

A magneto-optical transducer including a magnetic layer on a transparent, non-magnetic substrate is used to characterize the performance of a write head based on optically detected magnetization in the magnetic layer. The write head sample is held in contact with or near the magnetic layer, which is illuminated through the substrate with linearly polarized light. Magnetization in the write head produces a magnetization in the magnetic layer, which alters the polarization state in reflected light. The reflected light is analyzed and the intensity detected using an optical detector, such as one or more photo-detectors or a camera. The performance of the write head can then be characterized using the detected intensity.

US Patent:

8427929, Apr 23, 2013

Filed:

Sep 7, 2011

Appl. No.:

13/227414

Inventors:

Henry Patland - Los Gatos CA, US
Juergen Heidmann - Salinas CA, US
Wade A. Ogle - San Jose CA, US
Alexander M. Taratorin - Palo Alto CA, US

Assignee:

Infinitum Solutions, Inc. - Santa Clara CA

International Classification:

G11B 7/00
G01R 33/032

US Classification:

369126, 3242441

Abstract:

A property, such as a quality parameter, of a write pole in a write head is determined using an optical metrology device, where the write pole is smaller than the optical resolution limit of the metrology device. The metrology device produces polarized light that is reflected off the write pole while the write pole is magnetized either during or after excitation with a write current. The magnetization alters the polarization state of the light, which can be analyzed to transform the altered polarization state into intensity. The intensity of the light is detected over the point spread function of the optics in the metrology device and an intensity value is generated. The intensity value is used to determine the quality parameter of the write pole, e. g. , by comparison to a threshold or reference intensity value, which may be generated empirically or theoretically.

US Patent:

20090147389, Jun 11, 2009

Filed:

Dec 10, 2007

Appl. No.:

11/953856

Inventors:

Alexander M. Taratorin - Sunnyvale CA, US
Henry Patland - Los Gatos CA, US
Wade A. Ogle - San Jose CA, US

Assignee:

Infinitum Solutions, Inc. - Santa Clara CA

International Classification:

G11B 27/36

US Classification:

360 31

Abstract:

A read head is tested by measuring the thermal magnetic fluctuation noise spectrum. A non-uniformity in the magnetic field of the free layer is produced and the thermal magnetic fluctuation noise spectrum is measured, with and/or without an external magnetic field applied. A peak in the thermal magnetic fluctuation noise spectrum can be used to derive the desired dimension of the free layer, such as track width and stripe height. The resulting measurement may then be fed back into the process control for the production of the read heads if desired. Additionally, the stiffness of the free layer and the strength of the reference layer may be determined using ferromagnetic resonance peaks in the thermal magnetic fluctuation noise spectrum.

US Patent:

20120056618, Mar 8, 2012

Filed:

Nov 15, 2011

Appl. No.:

13/296952

Inventors:

Alexander M. Taratorin - Palo Alto CA, US

Assignee:

Infinitum Solutions, Inc. - Santa Clara CA

International Classification:

G01R 33/12

US Classification:

324210

Abstract:

A write head is tested by measuring the effect that magnetic fields have on the inductance of the write head. For example, a perpendicular write head may be placed in a magnetic field with a first angle, e.g., non-parallel and non-perpendicular, to the air bearing surface and the inductance is measured. After altering the angle of the magnetic field the inductance is again tested. In another embodiment, the angles may be parallel and perpendicular to the air bearing surface. The difference in the inductance value can be used to determine a characteristic of the write head, such as the presence of a recording pole. In some embodiments, the inductance may be measured while applying a bias current to the write head while the write head is in an external magnetic field.

US Patent:

20120056619, Mar 8, 2012

Filed:

Nov 16, 2011

Appl. No.:

13/298062

Inventors:

Alexander M. Taratorin - Palo Alto CA, US

Assignee:

Infinitum Solutions, Inc. - Santa Clara CA

International Classification:

G01R 33/12

US Classification:

324210

Abstract:

A write head is tested by measuring the effect that magnetic fields have on the inductance of the write head. For example, a perpendicular write head may be placed in a magnetic field with a first angle, e.g., non-parallel and non-perpendicular, to the air bearing surface and the inductance is measured. After altering the angle of the magnetic field the inductance is again tested. In another embodiment, the angles may be parallel and perpendicular to the air bearing surface. The difference in the inductance value can be used to determine a characteristic of the write head, such as the presence of a recording pole. In some embodiments, the inductance may be measured while applying a bias current to the write head while the write head is in an external magnetic field.

US Patent:

20130294210, Nov 7, 2013

Filed:

Mar 11, 2013

Appl. No.:

13/794404

Inventors:

Alexander M. Taratorin - Palo Alto CA, US

Assignee:

Infinitum Solutions, Inc. - Santa Clara CA

International Classification:

G11B 5/455

US Classification:

369 5338

Abstract:

A testing device tests a magnetic head with a read head structure including a read head element while applying an external magnetic field to the magnetic head. The testing device receives signals from the read head element and processes the signals to generate a spectral power density for the signals. The spectral power density is characterized for at least one frequency range. The characterization of the spectral power density is used to determine a characteristic of noise from the read head structure. The signals from the read head may be received with different applied magnetic fields and/or before or while thermally exciting the magnetic head. Additionally, a histogram of the signals may be generated and used to determine a second characteristic of the noise.