Patents by Inventor Weldon Mark Hanson
Weldon Mark Hanson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10008229Abstract: A method, apparatus, and system are provided for implementing track following using signal asymmetry metrics monitored during read back in hard disk drives (HDDs). Signal asymmetry metrics monitored during read back are used together with a position error signal (PES) to correct and guide the position of a read sensor with respect to a written track in the HDD.Type: GrantFiled: January 5, 2016Date of Patent: June 26, 2018Assignee: WESTERN DIGITAL TECHNOLOGIES, INCInventors: Richard Leo Galbraith, Weldon Mark Hanson, Mark A. Nichols, Alexander Taratorin, Roger William Wood
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Patent number: 9886979Abstract: A method, apparatus, and system are provided for implementing an enhanced modulation code for hard disk drives (HDDs). A modulation code directly uses Bit Error Rate (BER) information for different user patterns to construct a coded word minimizing possible error rate. The modulation code has a flexible code rate that simplifies code optimization relative to Coded Bit Density (CBD), signal to noise ratio (SNR) and noise color.Type: GrantFiled: December 30, 2016Date of Patent: February 6, 2018Assignee: Western Digital Technologies, Inc.Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Iouri Oboukhov, Gary William Walker
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Publication number: 20170194024Abstract: A method, apparatus, and system are provided for implementing track following using signal asymmetry metrics monitored during read back in hard disk drives (HDDs). Signal asymmetry metrics monitored during read back are used together with a position error signal (PES) to correct and guide the position of a read sensor with respect to a written track in the HDD.Type: ApplicationFiled: January 5, 2016Publication date: July 6, 2017Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Mark A. Nichols, Alexander Taratorin, Roger William Wood
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Patent number: 9437232Abstract: A hard disk drive is adapted to take the most recent estimated read head positions (the position error signal or PES values) that are obtained during writing and write those values into the data sectors as written PES (WPES) values. The WPES values are available on readback for use as a predictor of the positions in which subsequent data sectors were written and are also available for use in a data recovery procedure should a particular data sector fail to be recovered. In two-dimensional magnetic recording, the difference between the WPES value and the read PES value is a quantity required to rapidly select the best 2D equalizer. The PES values may be encoded prior to being written into the data sectors. The WPES values are appended to the data sectors after the preamble and sync fields, which occur after every servo sector.Type: GrantFiled: July 15, 2015Date of Patent: September 6, 2016Assignee: HGST Netherlands B.V.Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Roger William Wood
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Patent number: 9275656Abstract: Disk drives with a Channel System and Write Driver Preamp architecture that dynamically adjusts the write driver's signal wave-shape depending on the write data signal pattern are described. The wave-shape control signal is generated in the Channel and transmitted to the Write Driver Preamp. Embodiments of the invention provide discrete n-level overshoot amplitude control using amplitude-level modulated (AML) signal. One embodiment implements a look-ahead strategy overshoot amplitude control where the overshoot amplitude for each transition depends only on the subsequent (following) bits in the data stream and not on any previously recorded data.Type: GrantFiled: July 20, 2015Date of Patent: March 1, 2016Assignee: HGST Netherlands B.V.Inventors: John Contreras, Samir Y. Garzon, Weldon Mark Hanson, Alexander Taratorin
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Patent number: 9218847Abstract: A method of testing a one or more components of a data storage system introduces a first plurality of micro-transitions into a first data write pattern, which is then written to a magnetic media. A read-back signal is generated, and a frequency response of the read-back signal is analyzed to determine performance of the one or more components of the data storage system.Type: GrantFiled: December 18, 2013Date of Patent: December 22, 2015Assignee: HGST NETHERLANDS B.V.Inventors: Weldon Mark Hanson, Michael Paul Salo, Alexander Taratorin, Roger William Wood
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Patent number: 9111561Abstract: A disk drive dynamic wave shaper (DWS) write driver includes a write current generator that produces a baseline output current for the write current pulses and an overshoot current generator that produces an overshoot current with different values. The overshoot current is added to the baseline current, with the value of the overshoot current amplitude (OSA) being selected in response to the frequency of transitions in the write data signal. The write driver includes logic circuitry that detects the pattern of transitions. Transitions that are immediately followed by a transition will receive a larger-than-nominal OSA1, transitions that are not immediately followed by a transition and that are not preceded by a long sequence of non-transitions will receive a nominal OSA2, and transitions after longer sequences of non-transitions will receive a smaller-than-nominal OSA3.Type: GrantFiled: October 28, 2014Date of Patent: August 18, 2015Assignee: HGST Netherlands B.V.Inventors: John Contreras, Samir Y. Garzon, Weldon Mark Hanson, Rehan Ahmed Zakai
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Publication number: 20150170707Abstract: A method of testing a one or more components of a data storage system introduces a first plurality of micro-transitions into a first data write pattern, which is then written to a magnetic media. A read-back signal is generated, and a frequency response of the read-back signal is analyzed to determine performance of the one or more components of the data storage system.Type: ApplicationFiled: December 18, 2013Publication date: June 18, 2015Applicant: HGST Netherlands B.V.Inventors: Weldon Mark HANSON, Michael Paul SALO, Alexander TARATORIN, Roger William WOOD
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Patent number: 9059737Abstract: Disk drives are described in which blocks of data spanning multiple sectors are encoded into a plurality of codewords which are then divided into segments that are physically separated (distributed) on the disk surface over multiple sectors in a distributed codeword block so that the codewords have an improved worst case SNR in comparison to individual sectors. This results in more even SNR performance for each codeword, which improves the performance for portions of a track which have lower than the average SNR. Embodiments are described in which the distributed codeword blocks span across tracks.Type: GrantFiled: May 1, 2013Date of Patent: June 16, 2015Assignee: HGST Netherlands B.V.Inventors: Jonathan Darrel Coker, Richard Leo Galbraith, Weldon Mark Hanson, Travis Roger Oenning, Roger William Wood
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Patent number: 8988807Abstract: A hard disk drive has disks with data sector preambles that allow for inter-track interference. The same data sector preamble is used for all data sectors in a track but the preamble in each track is different from the preamble in radially adjacent tracks. In a first embodiment each preamble includes a synchronization field (SF) and synchronization mark (SM) that are the same in each track but different from the SF and SM in radially adjacent tracks. Only two unique SFs and two unique SMs are required, with the two SFs and two SMs alternating in radially adjacent tracks. In a second embodiment the preambles are “integrated”, meaning that the preamble is a sequence of bits that does not include separate dedicated fields, like SF and SM. The preamble bit sequences are decoded using matched filters to provide bit synchronization and start-of-data information.Type: GrantFiled: September 19, 2013Date of Patent: March 24, 2015Assignee: HGST Netherlands B.V.Inventors: Jonathan Darrel Coker, Richard Leo Galbraith, Weldon Mark Hanson, Travis Roger Oenning, Srinivasan Surendran
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Publication number: 20150077875Abstract: A hard disk drive has disks with data sector preambles that allow for inter-track interference. The same data sector preamble is used for all data sectors in a track but the preamble in each track is different from the preamble in radially adjacent tracks. In a first embodiment each preamble includes a synchronization field (SF) and synchronization mark (SM) that are the same in each track but different from the SF and SM in radially adjacent tracks. Only two unique SFs and two unique SMs are required, with the two SFs and two SMs alternating in radially adjacent tracks. In a second embodiment the preambles are “integrated”, meaning that the preamble is a sequence of bits that does not include separate dedicated fields, like SF and SM. The preamble bit sequences are decoded using matched filters to provide bit synchronization and start-of-data information.Type: ApplicationFiled: September 19, 2013Publication date: March 19, 2015Applicant: HGST Netherlands B.V.Inventors: Jonathan Darrel Coker, Richard Leo Galbraith, Weldon Mark Hanson, Travis Roger Oenning, Srinivasan Surendran
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Publication number: 20150077876Abstract: A hard disk drive has disks with data sector preambles that allow for inter-track interference. The same data sector preamble is used for all data sectors in a track but the preamble in each track is different from the preamble in radially adjacent tracks. In a first embodiment each preamble includes a synchronization field (SF) and synchronization mark (SM) that are the same in each track but different from the SF and SM in radially adjacent tracks. Only two unique SFs and two unique SMs are required, with the two SFs and two SMs alternating in radially adjacent tracks. In a second embodiment the preambles are “integrated”, meaning that the preamble is a sequence of bits that does not include separate dedicated fields, like SF and SM. The preamble bit sequences are decoded using matched filters to provide bit synchronization and start-of-data information.Type: ApplicationFiled: September 19, 2013Publication date: March 19, 2015Applicant: HGST Netherlands B.V.Inventors: Jonathan Darrel Coker, Richard Leo Galbraith, Weldon Mark Hanson, Travis Roger Oenning, Srinivasan Surendran
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Patent number: 8982491Abstract: A hard disk drive has disks with data sector preambles that allow for inter-track interference. The same data sector preamble is used for all data sectors in a track but the preamble in each track is different from the preamble in radially adjacent tracks. In a first embodiment each preamble includes a synchronization field (SF) and synchronization mark (SM) that are the same in each track but different from the SF and SM in radially adjacent tracks. Only two unique SFs and two unique SMs are required, with the two SFs and two SMs alternating in radially adjacent tracks. In a second embodiment the preambles are “integrated”, meaning that the preamble is a sequence of bits that does not include separate dedicated fields, like SF and SM. The preamble bit sequences are decoded using matched filters to provide bit synchronization and start-of-data information.Type: GrantFiled: September 19, 2013Date of Patent: March 17, 2015Assignee: HGST Netherlands B.V.Inventors: Jonathan Darrel Coker, Richard Leo Galbraith, Weldon Mark Hanson, Travis Roger Oenning, Srinivasan Surendran
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Publication number: 20140201590Abstract: Disk drives are described in which blocks of data spanning multiple sectors are encoded into a plurality of codewords which are then divided into segments that are physically separated (distributed) on the disk surface over multiple sectors in a distributed codeword block so that the codewords have an improved worst case SNR in comparison to individual sectors. This results in more even SNR performance for each codeword, which improves the performance for portions of a track which have lower than the average SNR. Embodiments are described in which the distributed codeword blocks span across tracks.Type: ApplicationFiled: May 1, 2013Publication date: July 17, 2014Applicant: HGST Netherlands B.V.Inventors: Jonathan Darrel Coker, Richard Leo Galbraith, Weldon Mark Hanson, Travis Roger Oenning, Roger William Wood
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Patent number: 8736997Abstract: A method, apparatus, and system are provided for implementing magnetic defect location detection on-the-fly for hard disk drives. A magnetic media readback signal of a hard disk drive is demodulated to generate phase modulation (PM) and amplitude modulation (AM) signals. A new coordinate plane defined by a combined phase modulation (PM) and amplitude modulation (AM) phasor-defect detector calculation function used to locate magnetic defects on-the-fly.Type: GrantFiled: June 13, 2012Date of Patent: May 27, 2014Assignee: HGST Netherlands B.V.Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Martin Aureliano Hassner, Travis Roger Oenning, Satoshi Yamamoto
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Patent number: 8736996Abstract: A method, apparatus, and system for implementing channel signal processing assist with an embedded contact sensor (ECS) in hard disk drives. An ECS signal is captured during write and idle operation of the hard disk drive. A read channel monitors changes in the ECS signal providing a clearance monitor function for insuring write integrity.Type: GrantFiled: May 18, 2012Date of Patent: May 27, 2014Assignee: HGST Netherlands B.V.Inventors: Xiaodong Che, Weldon Mark Hanson
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Patent number: 8654464Abstract: A method, apparatus, and system are provided for implementing magnetic defect classification using phase modulation for hard disk drives. A magnetic media readback signal of a hard disk drive is processed to identify predefined phase modulation (PM) characteristics to implement magnetic defect classification of magnetic media bump and pit defects.Type: GrantFiled: October 19, 2011Date of Patent: February 18, 2014Assignee: HGST Netherlands B.V.Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Martin Aureliano Hassner, Travis Roger Oenning, Satoshi Yamamoto
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Publication number: 20130335841Abstract: A method, apparatus, and system are provided for implementing magnetic defect location detection on-the-fly for hard disk drives. A magnetic media readback signal of a hard disk drive is demodulated to generate phase modulation (PM) and amplitude modulation (AM) signals. A new coordinate plane defined by a combined phase modulation (PM) and amplitude modulation (AM) phasor-defect detector calculation function used to locate magnetic defects on-the-fly.Type: ApplicationFiled: June 13, 2012Publication date: December 19, 2013Applicant: HGST NETHERLANDS B.V.Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Martin Aureliano Hassner, Travis Roger Oenning, Satoshi Yamamoto
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Patent number: 8599973Abstract: Embodiments of the present invention relate to the detection of synchronization marks in data storage and retrieval. According to one embodiment, synchronization marks are detected from the output of a matched filter, upstream of the Viterbi detector. This approach avoids the delay associated with the latency of the Viterbi output, thereby allowing time to align parity framing and to properly start the time-varying trellis. Certain embodiments disclose 34- and 20-bit primary synchronization marks located at the beginning of a data region. Other embodiments disclose 16-, 20-, and 24-bit embedded synchronization marks located within a data region.Type: GrantFiled: April 30, 2008Date of Patent: December 3, 2013Assignee: HGST Netherlands B.V.Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Travis Roger Oenning, Todd Carter Truax
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Publication number: 20130308220Abstract: A method, apparatus, and system for implementing channel signal processing assist with an embedded contact sensor (ECS) in hard disk drives. An ECS signal is captured during write and idle operation of the hard disk drive. A read channel monitors changes in the ECS signal providing a clearance monitor function for insuring write integrity.Type: ApplicationFiled: May 18, 2012Publication date: November 21, 2013Applicant: HGST NETHERLANDS B.V.Inventors: Xiaodong Che, Weldon Mark Hanson