Michael Jia Fwu Chen

US Patent:

7522365, Apr 21, 2009

Filed:

Apr 12, 2005

Appl. No.:

11/103900

Inventors:

Michael Chen - Westminster CO, US

Assignee:

Maxtor Corporation - Scotts Valley CA

International Classification:

G11B 5/09
G11B 27/36
G11B 5/03
G11B 5/58

US Classification:

360 53, 360 31, 360 66, 360 7701

Abstract:

A magnetic storage system includes a disk, a head, an actuator, a read channel, and a main controller. The main controller causes the head to read a data block of a selected track of the disk at each of a plurality of fixed offsets from a center of the selected track. The main controller samples a gain in the read channel a plurality of times while the head is reading the data block at each of the plurality of fixed offsets to obtain a plurality of gain samples for each of the plurality of fixed offsets. If the data block was written off-track with a non-constant offset, the main controller determines an approximate starting position and an approximate rate of change of an off-track deviation of the data block based on the plurality of gain samples for the plurality of fixed offsets.

US Patent:

7634706, Dec 15, 2009

Filed:

Jul 5, 2006

Appl. No.:

11/481078

Inventors:

Michael H. Chen - Westminster CO, US
Rajita Shrestha - Westminster CO, US
James C. Alexander - Boulder CO, US

Assignee:

Seagate Technology LLC - Scotts Valley CA

International Classification:

H03M 13/43

US Classification:

714760

Abstract:

A system for enhancing the error correction capability of an error correction code (“ECC”) during error recovery operations accumulates, for respective bits, counts of the number of times the bits are detected as 1s in multiple re-reads of a data signal. The system then determines, based on the associated count, if a reconstructed bit should be considered a 1 or 0, or neither, that is, if the reconstructed bit should be considered erroneous, by comparing the count to a majority detection threshold and then to either an upper or a lower predetermined threshold that corresponds to the confidence with which the bit is reconstructed as a either a 1 or a 0. If the confidence is sufficiently low, that is, if the count falls below the upper threshold or above the lower threshold, the reconstructed bit is flagged as erroneous. After all of the bits are reconstructed, the system groups the bits into symbols to reproduce the ECC codeword, and sets erasure pointers that identify the locations of a predetermined number, s, of the symbols that are associated with the highest degree of uncertainty, that is, the largest numbers of flagged bits or, as appropriate, the largest numbers of flagged bits with the lowest confidence levels. The error correction operation then decodes the symbols in the identified locations as erasures.

US Patent:

8059353, Nov 15, 2011

Filed:

Aug 25, 2008

Appl. No.:

12/197508

Inventors:

Michael Chen - Westminster CO, US

Assignee:

Seagate Technology LLC - Scotts Valley CA

International Classification:

G11B 5/09
G11B 27/36
G11B 5/03
G11B 5/58

US Classification:

360 53, 360 31, 360 66, 360 7701

Abstract:

A magnetic storage system includes a disk, a head, an actuator, a read channel, and a main controller. The main controller causes the head to read a data block of a selected track of the disk at each of a plurality of fixed offsets from a center of the selected track. The main controller samples a gain in the read channel a plurality of times while the head is reading the data block at each of the plurality of fixed offsets to obtain a plurality of gain samples for each of the plurality of fixed offsets. If the data block was written off-track with a non-constant offset, the main controller determines an approximate starting position and an approximate rate of change of an off-track deviation of the data block based on the plurality of gain samples for the plurality of fixed offsets.

US Patent:

8196001, Jun 5, 2012

Filed:

Nov 5, 2009

Appl. No.:

12/613058

Inventors:

Michael H. Chen - Westminster CO, US
Rajita Shrestha - Westminster CO, US
James C. Alexander - Boulder CO, US

Assignee:

Seagate Technology LLC - Cupertino CA

International Classification:

H03M 13/00

US Classification:

714752, 714760

Abstract:

Systems for identifying potentially erroneous and/or erased data are provided. Systems have a bit detector, an accumulator, and a data reconstruction processor. The bit detector assigns values to bits read in a data signal. The bit detector illustratively assigns multiple values to each of the bits. The accumulator accumulates a count of the multiple values assigned by the bit detector for each of the bits. The accumulator associates each bit with a particular value based at least in part on its accumulated count. The data reconstruction processor determines for each of the bits a confidence level of the particular value associated to it. The data reconstruction process sets flags for a portion of the bits. The flags identify the portion of the bits as possible erased or erroneous data. The flags are set based at least in part on the confidence levels of the portion of the bits.

US Patent:

49507206, Aug 21, 1990

Filed:

Apr 29, 1988

Appl. No.:

7/188260

Inventors:

James C. Randall - Seabrook TX
Ferdinand C. Stehling - Baytown TX
Michael C. Chen - Deer Park TX
Larry W. Colwell - Friendswood TX

Assignee:

Exxon Chemical Patents Inc. - Linden NJ

International Classification:

C08L 2312
C08L 2316
C08F29708

US Classification:

525322

Abstract:

A modified polypropylene having a substantially isotactic homopolypropylene and a propylene/olefin random copolymer, the modified polypropylene including up to about 50 chain disruptors per 1000 propylene repeat units. The chain disruptors are racemic polypropylene diads and olefin, the olefin being incorporated into the high end of the molecular weight distribution of the modified polypropylene.

US Patent:

20180076961, Mar 15, 2018

Filed:

Jul 26, 2017

Appl. No.:

15/659950

Inventors:

- Philadelphia PA, US
James W. Fahrny - Parker CO, US
Allen Broome - Broomfield CO, US
Michael A. Chen - Wallingford PA, US

International Classification:

H04L 9/32
H04N 21/845
H04N 21/8358
H04N 21/8352
H04N 21/4627
H04N 21/00
H04N 1/32
H04N 21/41

Abstract:

The disclosure relates to processing content with watermarks to generate watermarked versions. In some aspects, each version may be different. Groups of fragments may be combined to generate a unique stream by pulling fragments from two or more of the groups of fragments. Further, fragmenting may be performed before watermarking, and fragments may be pulled and watermarked upon request.