Qiang Ling from 2104 Teal Trce, Pittsburgh, PA 15237, age 48, Phone: 412 369-0669

Null Servo Pattern For Bit-Patterned Media
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US Patent:

7706092, Apr 27, 2010
Filed:

Sep 12, 2007
Appl. No.:

11/854013
Inventors:

Qiang Ling - Pittsburgh PA, US
Mehmet Fatih Erden - Pittsburgh PA, US
Alexei H. Sacks - Edina MN, US
Sundeep Chauhan - Edina MN, US
Assignee:

Seagate Technology LLC - Scotts Valley CA
International Classification:

G11B 5/09
US Classification:

360 48, 360 29, 360 75
Abstract:

A patterned recording media comprises a segment and a null pattern formed in the segment. The segment comprises first and second rows of discrete magnetic elements separated by a non-magnetic material, and a row of non-magnetic material positioned between the first and second rows. The null pattern comprises consecutive groups of the discrete magnetic elements in the first and second rows of the segment. Each group in the first row has a magnetic polarity that is opposite the magnetic polarity of adjoining groups in the first row. Each group in the second row has a magnetic polarity that is opposite the magnetic polarity of adjoining groups in the second row.

Compensating The Effects Of Non-Synchronous Writing Of Erasable Servo Marks
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US Patent:

8023392, Sep 20, 2011
Filed:

Dec 15, 2006
Appl. No.:

11/639728
Inventors:

Qiang Ling - Pittsburgh PA, US
Mehmet Fatih Erden - Pittsburgh PA, US
Assignee:

Seagate Technology LLC - Cupertino CA
International Classification:

G11B 9/00
US Classification:

369126
Abstract:

A method is provided, which includes reading data from a data storage medium. Reading data from the medium causes the data to be erased. The method further includes determining a desired position to rewrite the data by computing a position error signal based on the data signal and compensating the position error signal for non-zero bias. The data is then rewritten non-synchronously. An apparatus is also provided, including a data storage medium with a data communication transducer configured to receive data from the medium. Data is erased after it is read. The data communication transducer is configured to rewrite the read data back onto the data storage medium in a non-synchronously. A non-zero bias compensator is provided to compensate data received by the data communication transducer to determine a desired position to rewrite the previously read data back onto the medium.

Low Complexity Servo Demodulation Algorithm For Probe Storage
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US Patent:

20090086360, Apr 2, 2009
Filed:

Oct 2, 2007
Appl. No.:

11/866219
Inventors:

Qiang Ling - Pittsburgh PA, US
Mehmet Fatih Erden - Pittsburgh PA, US
Assignee:

Seagate Technology LLC - Scotts Valley CA
International Classification:

H03M 1/12
G11B 21/02
H03M 3/02
US Classification:

360 75, 341143, 341155
Abstract:

A method of calculating a position error signal is provided. The method includes receiving an analog signal from a data channel and converting the analog signal to a one bit wide digital signal. The analog signal is converted to a digital signal at an oversampled frequency. The position error signal is then calculated by summing correlated oversampled digital signals.

Servo Sector Format With Large Lithographic Tolerances
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US Patent:

7576942, Aug 18, 2009
Filed:

Apr 22, 2008
Appl. No.:

12/107521
Inventors:

Darren William Karns - Evans City PA, US
Mark David Bedillion - Allison Park PA, US
Qiang Ling - Pittsburgh PA, US
Mehmet Fatih Erden - Pittsburgh PA, US
Assignee:

Seagate Technology LLC - Scotts Valley CA
International Classification:

G11B 5/596
US Classification:

360 7708
Abstract:

A method and system determines the position of a transducer head based on permanent servo marks in which the width of the permanent servo marks is greater than the width of the data tracks they are used to identify. The method includes receiving readback signals in response to the permanent servo marks arranged as a number of null bursts and generating position error signals with respect to each null burst. Region based information is extracted based on the position error signals, and the region based information is used in conjunction with the position error signals to generate region-based displacement estimates with respect to each null burst. The region-based estimates are then combined to generate a final displacement estimate that describes the estimated distance between a transducer head and the centerline of a desired data track.