Patents Assigned to Seagate Technologies LLC
  • Write current switching in a data storage device
    Patent number: 9905251
    Abstract: Method and apparatus for enhancing write current switching efficiencies during data write operations in a data storage device. In some embodiments, write data are described in the form a sequence of symbols of nT length where T is a channel clock rate and n is an integer over a selected range. Bi-directional write currents are applied to a write element to record the sequence of symbols to a storage medium. The write currents are switched between a first rail current and a second rail current for alternating symbols. The write currents are further transitioned to an intermediate current value for at least one channel clock period immediately preceding a next occurrence of a symbol boundary between an adjacent pair of symbols in the sequence.
    Type: Grant
    Filed: February 15, 2016
    Date of Patent: February 27, 2018
    Assignee: Seagate Technology LLC
    Inventors: Xiong Liu, Michael R. Montemorra, Ralph W. Cross, Todd M. Lammers, Quan Li, Beng Theam Ko, Kirill Rivkin, Mourad Benakli
  • Methods and devices for detecting shock events
    Patent number: 9905273
    Abstract: An apparatus includes an actuator assembly, a dampening assembly coupled to the actuator assembly, and a vibration sensor assembly coupled to the dampening assembly and coupled to the actuator assembly by way of the dampening assembly. A method includes attaching a dampening assembly to an actuator assembly and attaching a vibration sensor assembly to the dampening assembly. The dampening assembly is positioned between the vibration sensor assembly and the actuator assembly.
    Type: Grant
    Filed: April 26, 2016
    Date of Patent: February 27, 2018
    Assignee: Seagate Technology LLC
    Inventors: Antanas Daugela, Neal F. Gunderson, Reed D. Hanson, Ricardo P. Freeman, Andrew R. Motzko, Erik J. Lindquist
  • Writing logically offset pages of data to N-level memory cells coupled to a common word line
    Patent number: 9905294
    Abstract: Method and apparatus for managing data in a data storage device. In some embodiments, a non-volatile cache memory stores a sequence of pages from a host device. A non-volatile main memory has a plurality of n-level cells arranged on m separate integrated circuit dies each simultaneously accessible during programming and read operations using an associated transfer circuit, where m and n are plural numbers. A control circuit writes first and second pages from the sequence of pages to a selected set of the n-level cells coupled to a common word line on a selected integrated circuit die. The second page is separated from the first page in the sequence of pages by a logical offset comprising a plurality of intervening pages in the sequence of pages. The logical offset is selected responsive to the m number of integrated circuit dies and a delay time associated with the transfer circuits.
    Type: Grant
    Filed: May 3, 2017
    Date of Patent: February 27, 2018
    Assignee: Seagate Technology LLC
    Inventors: Timothy L. Canepa, Alex Tang, Stephen Hanna
  • Data reader with pinned front shield
    Patent number: 9899045
    Abstract: A data reader may have a magnetoresistive stack consisting of at least magnetically free and magnetically fixed structures. The magnetically fixed structure can be set to a first magnetization direction by a first pinning structure separated from an air bearing surface by a front shield portion of a magnetic shield. The front shield portion may be set to a different second magnetization direction by a second pinning structure.
    Type: Grant
    Filed: May 15, 2017
    Date of Patent: February 20, 2018
    Assignee: Seagate Technology LLC
    Inventors: Mark T. Kief, Kevin A. McNeill
  • Method of making a write pole
    Patent number: 9899041
    Abstract: A write pole of a data writer may have at least one rotational milling operation conducted on a write pole blank followed by first and second static milling operations executed at different first and second angles with respect to an air bearing surface. The combination of rotational and static milling operations can form a write pole with body and tip regions defined by a continuous pole sidewall extending perpendicularly from the air bearing surface up to a body taper portion angled at approximately 14.5° with respect to the air bearing surface.
    Type: Grant
    Filed: April 8, 2016
    Date of Patent: February 20, 2018
    Assignee: Seagate Technology LLC
    Inventors: Aji Baby, Marcus B. Mooney, Mark A. Gubbins
  • Methods of forming near field transducers and near field transducers formed thereby
    Patent number: 9899043
    Abstract: A method of forming a near field transducer (NFT), the method including the steps of depositing a plasmonic material; depositing an encapsulant material on at least a portion of the plasmonic material; and implanting ions into at least a portion of the plasmonic material through the encapsulant material.
    Type: Grant
    Filed: February 13, 2017
    Date of Patent: February 20, 2018
    Assignee: Seagate Technology LLC
    Inventors: Sethuraman Jayashankar, Hui Brickner
  • Multiple layer FePt structure
    Patent number: 9899050
    Abstract: One embodiment described herein is directed to a method involving depositing a seed layer on a substrate, the seed layer comprising A1 phase FePt with a ratio of Pt of Fe greater than 1:1. A main layer is deposited on the seed layer, the main layer comprising A1 phase FePt with a ratio of Pt to Fe of approximately 1:1. A cap layer is deposited on the main layer, the cap layer comprising A1 phase FePt with a ratio of Pt to Fe of less than 1:1. The seed, main and cap layers are annealed to convert the A1 phase FePt to L10 phase FePt having a graded FePt structure of varying stoichimetry from approximately Fe50Pt50 adjacent a lower portion of the structure proximate the substrate to Fe>50Pt<50 adjacent an upper portion of the structure opposite the lower portion.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: February 20, 2018
    Assignee: Seagate Technology LLC
    Inventors: Jiaoming Qiu, Yonghua Chen, Ganping Ju, Thomas P. Nolan
  • Multi-tier detection and decoding in flash memories
    Patent number: 9898361
    Abstract: Methods and apparatus are provided for multi-tier detection and decoding in flash memory devices. Data from a flash memory device is processed by obtaining one or more read values for at least one bit in a given page of the flash memory device; converting the one or more read values for the at least one bit to a reliability value; performing an initial decoding of the at least one bit in a given page using the reliability value; and performing an additional decoding of the at least one bit in the given page if the initial decoding is not successful, wherein the additional decoding uses one or more of additional information for the given page and at least one value for at least one bit from at least one additional page.
    Type: Grant
    Filed: December 31, 2012
    Date of Patent: February 20, 2018
    Assignee: Seagate Technology LLC
    Inventors: Erich F. Haratsch, Abdel Hakim S. Alhussien
  • Data writer with laminated front shield
    Patent number: 9899042
    Abstract: A data storage device data writer may arrange a write pole to be positioned uptrack from a front shield on an air bearing surface. The front shield can consist of a lamination of a first magnetic alloy material and a second magnetic alloy material. The second magnetic alloy material may be NiFe that has 80% iron by weight.
    Type: Grant
    Filed: February 8, 2016
    Date of Patent: February 20, 2018
    Assignee: Seagate Technology LLC
    Inventors: Vijayaharan A. Venugopal, Muhammad Asif Bashir, Peter McGeehin, Marcus B. Mooney, Mark Gubbins
  • Protecting against unauthorized firmware updates using induced servo errors
    Patent number: 9899053
    Abstract: Method and apparatus for data security in a data storage device. In some embodiments, a first version of firmware is installed in a memory of the device. The firmware is used by a programmable processor to control accesses to a rotatable data recording medium on which is written pre-recorded servo positioning data used to position a data transducer. A newer, second version of the firmwave is subsequently installed in the memory to replace the first version of firmware. The second version of the firmware includes an instruction to corrupt a selected portion of the servo positioning data on the medium in order to authenticate the second version of the firmware. During a subsequent initialization of the device, host access is granted based on detection of the corruption of the selected portion of the servo positioning data.
    Type: Grant
    Filed: October 11, 2016
    Date of Patent: February 20, 2018
    Assignee: Seagate Technology LLC
    Inventors: Leroy L. Leach, Todd D. Baumann
  • Self-biasing storage device sled
    Patent number: 9888607
    Abstract: A self-biasing storage device sled for mounting a storage device within a chassis is provided. The self-biasing storage device sled includes a bezel, which includes a first portion that is stationary relative to a storage device, a second portion vertically captured within the first portion and configured to slide between unlatching and latching positions, and a spring configured to push the latch outwardly from the bezel. The second portion includes a finger-movable member, a latch, and a horizontal biasing feature adjacent to the latch and configured to move in concert with the latch. When the storage device is installed in the chassis, the horizontal biasing feature exerts force against a first chassis interior side surface and biases the storage device sled against a second chassis interior side surface.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: February 6, 2018
    Assignee: Seagate Technology LLC
    Inventors: Kevin Lee Van Pelt, Christopher Ellis Schroeder
  • Noise cancellation in multitransducer recording
    Patent number: 9886970
    Abstract: In certain embodiments, an apparatus may comprise a first output driver connected to a first output via a first trace and a second output driver connected to a second output via a second trace. The first output driver may be configured to output a first drive signal to the first output to drive the first output and the first drive signal may cause first induced noise in the second trace. Further, the second output driver may be configured to output a second drive signal based on the first drive signal where the second drive signal may reduce the magnitude of the first induced noise at the second output.
    Type: Grant
    Filed: September 1, 2016
    Date of Patent: February 6, 2018
    Assignee: Seagate Technology LLC
    Inventors: Todd Michael Lammers, JianHua Xue, Javier I Guzman, Andrew Thomas Jaeb, Bruce Douglas Buch
  • Read head free layer having front and rear portions biased at different levels
    Patent number: 9886974
    Abstract: A reader having a bearing surface, a free layer, and a free layer biasing structure. The free layer biasing structure includes at least one side shield that applies a first bias field level to a front portion of the free layer that is nearest to the bearing surface and applies a second bias field level to a rear portion of the free layer that is farthest from the bearing surface. The second bias field level is greater than the first bias field level.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: February 6, 2018
    Assignee: Seagate Technology LLC
    Inventors: Scott Wilson Stokes, Victor Boris Sapozhnikov
  • Fine grained data retention monitoring in solid state drives
    Patent number: 9881682
    Abstract: Embodiments described herein provide for linking retention parameters that affect data retention in flash to data stored in the flash. One embodiment includes a flash memory and a controller. The controller receives a plurality of write requests from a host, and stores data for the write request in flash pages of the flash memory along with indicators. The controller identifies at least one retention parameter that affects data retention of the stored data, and adds one or more of the indicators to an entry in a journal along with the at least one retention parameter. In response to determining that a data refresh is warranted based on the at least one retention parameter, the controller identifies the one or more indicators associated with the at least one retention parameter in the entry, locates the stored data corresponding to the one or more indicators, and refreshes the stored data.
    Type: Grant
    Filed: November 23, 2016
    Date of Patent: January 30, 2018
    Assignee: Seagate Technology LLC
    Inventors: Alex Tang, Timothy Canepa, Ramdas Kachare
  • Log structured reserved zone for a data storage device
    Patent number: 9880926
    Abstract: A circuit may be configured to store data to a reserved zone of a non-volatile solid state memory (NVSSM) in a log structured manner and to use information stored in the reserved zone to restore data as needed. In some embodiments, a reserved area of a NVSSM may include die from one or more non-volatile memory modules, which can be divided into blocks and the blocks can be combined to form frames. In some examples, the frames may contain frame headers that can contain a unique identifier which can indicate which frame is to be used to restore data structures, such as during power up or for other restore events.
    Type: Grant
    Filed: August 20, 2013
    Date of Patent: January 30, 2018
    Assignee: Seagate Technology LLC
    Inventor: Sumanth Jannyavula Venkata
  • Recovering user data from a variably encroached data track
    Patent number: 9875763
    Abstract: Method and apparatus for recovering user data from a rotatable data recording medium. In some embodiments, a moveable read element detects at least one uncorrectable read error in user data stored in a data sector arranged along a concentric track. A read retry operation is carried out to recover the user data by radially advancing the moveable read element from a first offset value to a different second offset value with respect to the track in accordance with a trajectory profile while transducing the user data from the data sector. This allows data that are variably overwritten (encroached upon) by different radial amounts from an adjacent track to be recovered.
    Type: Grant
    Filed: October 24, 2016
    Date of Patent: January 23, 2018
    Assignee: Seagate Technology LLC
    Inventors: Jason C. Jury, Siong Liu, Joshua W. Christensen
  • Stabilization of one or more upper sensors in multi-sensor readers
    Patent number: 9870791
    Abstract: A multi-sensor reader that includes a first sensor that has a first sensor stack, which includes a sensing layer that has a magnetization that changes according to an external magnetic field. The first sensor also includes a first seed layer below the first sensor stack. The multi-sensor reader also includes a second sensor stacked over the first sensor. The second sensor includes a second sensor stack, which includes a sensing layer that has a magnetization that changes according to the external magnetic field. The second sensor also includes a second seed layer below the second sensor stack. A stabilization element is included to maintain a magnetization direction of the second seed layer and to stabilize the second seed layer.
    Type: Grant
    Filed: April 17, 2017
    Date of Patent: January 16, 2018
    Assignee: Seagate Technology LLC
    Inventors: Victor Sapozhnikov, Steven P. Bozeman, Mohammed Shariat Ullah Patwari, LiWen Tan, Jae Young Yi, Eric W. Singleton
  • Materials for near field transducers and near field transducers containing same
    Patent number: 9870793
    Abstract: A method of forming a near field transducer (NFT) layer, the method including depositing a film of a primary element, the film having a film thickness and a film expanse; and implanting at least one secondary element into the primary element, wherein the NFT layer includes the film of the primary element doped with the at least one secondary element.
    Type: Grant
    Filed: March 9, 2016
    Date of Patent: January 16, 2018
    Assignee: Seagate Technology LLC
    Inventors: Sethuraman Jayashankar, Michael C. Kautzky
  • Photon emitter array including photon emitters with different orientations
    Patent number: 9869639
    Abstract: Provided herein is an apparatus including a photon emitter array. The photon emitter array includes a number of photon emitters selectively oriented in a number of polarized orientations. The photon emitters are configured to controllably emit photons onto a surface of an article. The apparatus also includes a photon detector positioned to receive photons scattered from features on the surface of the article. The photon detector simultaneously receives photons oriented in the number of polarized orientations. In addition, the photon detector provides information for mapping the features on the surface of the article.
    Type: Grant
    Filed: November 30, 2016
    Date of Patent: January 16, 2018
    Assignee: Seagate Technology LLC
    Inventors: Joachim Walter Ahner, David Marcus Tung
  • Recessed AFM stitch interface engineering
    Patent number: 9870790
    Abstract: A read sensor and fabrication method thereof. The method includes forming a bottom stack that includes an antiferromagnetic (AFM) layer, a lower ferromagnetic stitch layer above the AFM layer and a sacrificial cap layer on the lower ferromagnetic stitch layer. The sacrificial cap layer is formed of a material that alloys magnetically with the lower ferromagnetic stitch layer. The method further includes substantially removing the sacrificial cap layer. After substantially removing the sacrificial layer, an upper ferromagnetic stitch layer is deposited on the lower ferromagnetic stitch layer of the bottom stack to form a stitch interface that provides relatively strong magnetic coupling between the lower ferromagnetic stitch layer of the bottom stack and the upper ferromagnetic stitch layer.
    Type: Grant
    Filed: May 18, 2016
    Date of Patent: January 16, 2018
    Assignee: Seagate Technology LLC
    Inventors: Sameh Hassan, Yuqing Du, Marcus Ormston, Denis O'Donnell, Kevin McNeill