Patents Assigned to Seagate Technologies
  • Random number generation system with ring oscillators
    Patent number: 8583711
    Abstract: A random number generation system comprising one or more ring oscillators configured to generate entropy due to accumulated phase drift. A random number generator can include a ring oscillator configured to switch between a first state in which a signal of the ring oscillator oscillates between logic levels, and a second state in which the signal at least partially settles to one of the logic levels. The random number generator can also include a counter configured to measure a count of pulses of the signal and a whitener mechanism configured to receive the signal from the ring oscillator, latch a logic level of the signal from the ring oscillator, latch the count of pulses from the counter, and generate a random number based on the logic level and the count of pulses. Corresponding methods may also be performed.
    Type: Grant
    Filed: December 2, 2009
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventor: Laszlo Hars
  • Write delay stabilization
    Patent number: 8582226
    Abstract: Apparatus and method for write delay stabilization. A write driver is adapted to output bipolar write currents to write data to a memory. A preconditioning circuit is adapted to output first and second thermal preconditioning currents through the write driver to stabilize a write delay associated with the write driver to a steady-state level prior to the writing of data to the memory.
    Type: Grant
    Filed: March 15, 2012
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: David Erich Tetzlaff, Bruce Douglas Buch
  • Floating source line architecture for non-volatile memory
    Patent number: 8582347
    Abstract: A method and apparatus for writing data to a non-volatile memory cell, such as an STRAM memory cell or an RRAM memory cell. In some embodiments, a plurality of N non-volatile memory cells, where N is a greater than two, are connected to a common floating source line. A write circuit is adapted to program a selected memory cell of the plurality to a selected data state by passing a write current of selected magnitude through the selected memory cell and concurrently passing a portion of the write current in parallel through each of the remaining N?1 memory cells of the plurality via the common floating source line.
    Type: Grant
    Filed: January 28, 2013
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: Chulmin Jung, Yong Lu, Harry Hongyue Liu
  • Magnetic sensor with non-rectangular geometry
    Patent number: 8582251
    Abstract: Various embodiments generally relate to a magnetic sensor, and more specifically to a magnetoresistive read head sensor. In one such exemplary embodiment, a magnetic sensor comprises a sensor stack and magnetic bias elements positioned adjacent opposite sides of the sensor stack. At least one of the bias elements has a non-rectangular shape, such as substantially trapezoidal or parallelogram shapes having non-perpendicular corners.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Lei Wang, Jiaoming Qiu, Yonghua Chen
  • Press fitting a cartridge bearing
    Patent number: 8579514
    Abstract: An apparatus and associated method involving an actuator assembly having an actuator body defining a bore and a bearing assembly in the bore. The bearing assembly has a shaft, and further has a bearing having an inner race that is affixed to the shaft and an outer race that is rotatable relative to the inner race. The bearing also has a sleeve defining an annular rigid portion circumscribing the outer race and affixed thereto. The sleeve further defines an annular predictably deformable portion depending from the rigid portion that is entirely disposed longitudinally distant from the outer race and sized to deform when press fit into the bore to operably align the shaft in the bore.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventor: Tave Joseph Fruge
  • Selectively magnetic write gap insert
    Patent number: 8582237
    Abstract: A selectively magnetic insert that is capable of enhancing magnetic writing, such as in use as a data transducing head. In accordance with various embodiments, a write pole is in contact with a selectively magnetic insert that decouples the write pole from at least one adjacent shield in response a powered operation.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: James Gary Wessel, Mourad Benakli, Raul Horacio Andruet, Kirill A. Rivkin, Sarbeswar Sahoo
  • Magnetic transducer including basecoat and overcoat
    Patent number: 8582242
    Abstract: A magnetic head that includes: a slider having a leading edge and a trailing edge; and a transducer, the transducer formed on the trailing edge of the slider and the transducer including: a substrate; a basecoat positioned adjacent the substrate, wherein the basecoat includes a material having a Young's modulus that is less than that of alumina and a coefficient of thermal expansion that is less than that of alumina; a reader; a writer; a heater; and an overcoat encasing at least a portion of the transducer, wherein the overcoat includes a material having a Young's modulus that is less than that of alumina and a coefficient of thermal expansion that is less than that of alumina.
    Type: Grant
    Filed: September 29, 2011
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: Paul Julio Sonda, Edwin Frank Rejda, Declan Macken
  • Double biasing for trilayer MR sensors
    Patent number: 8582250
    Abstract: A trilayer magnetoresistive sensor has at least first and second ferromagnetic layers separated by a nonmagnetic layer. A high coercivity permanent magnet bias element biases the first ferromagnetic layer in a first direction. A high moment permanent magnet bias element biases the second ferromagnetic layer in a second direction substantially orthogonal to the first direction.
    Type: Grant
    Filed: December 4, 2009
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: Jiaoming Qiu, Yonghua Chen, Kaizhong Gao
  • Magnetic Sensor Seed Layer with Magnetic and Nonmagnetic Layers
    Publication number: 20130293225
    Abstract: A magnetic sensor has a bottom shield layer, an upper shield layer, and a sensor stack adjacent the upper shield layer. The sensor includes a seed layer between the bottom shield layer and an antiferromagnetic layer of the sensor stack. The seed layer has a magnetic layer adjacent the sensor stack and a nonmagnetic layer adjacent the bottom shield layer.
    Type: Application
    Filed: December 15, 2011
    Publication date: November 7, 2013
    Applicant: Seagate Technology LLC
    Inventors: Eric Walter Singleton, Antonia Tsoukatos, Liwen Tan, Jae-Young Yi
  • Grating assisted surface emitter laser coupling for heat assisted magnetic recording
    Patent number: 8577193
    Abstract: An apparatus includes a waveguide, a laser diode positioned adjacent to the waveguide and having an active region producing light in a plane substantially parallel to a plane of the waveguide, a first grating positioned to couple light out of the laser diode and to direct the light toward the waveguide, a reflective layer positioned adjacent to a side of the first grating opposite to the waveguide, and a second grating having the same period as the first grating and positioned to couple light into the waveguide. A data storage device that includes the apparatus is also provided.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: November 5, 2013
    Assignee: Seagate Technology LLC
    Inventor: Lifu Zhou
  • Biasing a pre-metalized non-conductive substrate
    Patent number: 8573579
    Abstract: Methods and apparatus are provided for static-biasing a pre-metalized non-conductive substrate within a process chamber. A substrate holder that holds a pre-metalized non-conductive substrate is engaged by a lift mechanism that provides movement of the substrate in a first, upward direction to a contact position within the process chamber and in a second direction to a non-contact position. When the substrate holder is moved to the contact position, the substrate electrically engages a conductive spring-loaded compliance mechanism that is mounted in a fixed position within the process chamber. The spring-loaded compliance mechanism is connected to a bias-voltage feed-through for the process chamber that applies a bias voltage to the substrate via the spring-loaded compliance mechanism.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: November 5, 2013
    Assignee: Seagate Technology LLC
    Inventors: Chang Bok Yi, Tatsuru Tanaka, Chun Wai Joseph Tong, Hongling Liu, Paul S. McLeod
  • Thin film structure with controlled lateral thermal spreading in the thin film
    Patent number: 8576515
    Abstract: An apparatus includes a non-metallic interlayer between a magnetic data storage layer and a heat sink layer, wherein interface thermal resistance between the interlayer and the heat sink layer is capable of reducing heat flow between the heat sink layer and the magnetic data storage layer. The apparatus may be configured as a thin film structure arranged for data storage. The apparatus may also include thermal resistor layer positioned between the interlayer and the heat sink layer.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: November 5, 2013
    Assignee: Seagate Technology LLC
    Inventors: Julius K. Hohlfeld, Bin Lu, Ganping A. Ju, Amit V. Itagi, Timothy Klemmer, Yingguo Peng, Yukiko Kubota
  • Heat sink layer
    Patent number: 8576672
    Abstract: A layer configured for use in a magnetic stack has electrical resistivity greater than about 5×10?8 ?m and thermal conductivity greater than about 1 W/mK. In some arrangements, the magnetic stack includes a substrate with the layer disposed over the substrate, a magnetic recording layer disposed over the layer, and a thermal resist layer disposed between the layer and the magnetic recording layer. In some arrangements, the layer is configured to function as a heat sink and a soft under layer. A system that incorporates the layer can include a magnetic write pole, a near field transducer (NFT) positioned proximate the write pole that radiates energy.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: November 5, 2013
    Assignee: Seagate Technology LLC
    Inventors: Chubing Peng, Edward Charles Gage, Ganping Ju, Jan-Ulrich Thiele, Kaizhong Gao
  • Disc drive data recovery utilizing off center track information
    Patent number: 8576507
    Abstract: Disc drive data recovery methods and systems that utilize off center track information are provided. A disc drive data track is illustratively read at a first position along a width of the data track and at a second position along the width of the data track. The data read from the track is stored and tagged with indications of the first and the second positions. The tagged data is optionally used to calculate average waveforms for each of the first and the second positions and to identify the average waveform having the highest signal-to-noise ratio.
    Type: Grant
    Filed: January 22, 2010
    Date of Patent: November 5, 2013
    Assignee: Seagate Technology LLC
    Inventor: Bernardo Rub
  • Storage device cache
    Patent number: 8578089
    Abstract: Implementations described and claimed herein provide a method and system for comparing a storage location related to a new write command on a storage device with storage locations of a predetermined number of write commands stored in a first table to determine frequency of write commands to the storage location. If the frequency is determined to be higher than a first threshold, the data related to the write command is stored in a write cache.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: November 5, 2013
    Assignee: Seagate Technology LLC
    Inventors: Ron Watts, Jack Lakey
  • Recording head for heat assisted magnetic recording with a side lobe blocker
    Patent number: 8576673
    Abstract: An apparatus includes a waveguide having a core layer, a near field transducer having an end positioned adjacent to a first surface, a first magnetic pole having an end positioned adjacent to the first surface, and a side lobe blocker adjacent to the first surface and having portions on opposite sides of the first magnetic pole and the near field transducer, wherein the side lobe blocker forms an aperture at an end of the core layer adjacent to the first surface.
    Type: Grant
    Filed: October 25, 2011
    Date of Patent: November 5, 2013
    Assignee: Seagate Technology LLC
    Inventors: Mark Henry Ostrowski, Jie Zou, Amit Itagi, Kaizhong Gao
  • METHOD AND APPARATUS FOR ADJUSTABLE VIRTUAL ADDRESSING FOR DATA STORAGE
    Publication number: 20130290668
    Abstract: Methods and apparatuses for adjusting the size of a virtual band or virtual zone of a storage medium are provided. In one embodiment, an apparatus may comprise a data storage device including a data storage medium having a physical zone; and a processor configured to receive a virtual addressing adjustment command, and adjust a number of virtual addresses in a virtual band mapped to the physical zone based on the virtual addressing adjustment command. In another embodiment, a method may comprise providing a data storage device configured to implement virtual addresses associated with a virtual band mapped to a physical zone of a data storage medium of the data storage device, receiving at the data storage device a virtual addressing adjustment command, and adjusting a number of virtual addresses in a virtual band based on the virtual addressing adjustment command.
    Type: Application
    Filed: April 27, 2012
    Publication date: October 31, 2013
    Applicant: Seagate Technology LLC
    Inventor: Se Wook Na
  • FLEX CIRCUIT WITH DUAL SIDED INTERCONNECT STRUCTURE
    Publication number: 20130286800
    Abstract: A flex circuit including a dual sided interconnect structure to connect electrical components on a head or suspension assembly to head circuitry is described. The dual sided interconnect structure described has application for providing an electrical connection to one or more transducer elements on a slider and one or more elements of a heat assisted magnetic recording HAMR unit. In an illustrated embodiment, a flexible structure or insulating base layer includes one or more slider and heat assisted magnetic recording traces coupled to one or more slider or HAMR bond pads on an interconnect portion. As disclosed, the slider bond pads are on the obverse side of the flexible structure and the HAMR bond pads include a reverse side bonding surface to form reverse side bond pads to connect to one or more electrical or heating elements on the HAMR unit.
    Type: Application
    Filed: March 15, 2013
    Publication date: October 31, 2013
    Applicant: Seagate Technology LLC
    Inventors: Bradley J. Ver Meer, Ravishankar Ajjanagadde Shivarama
  • LASER INDUCED SLIDER MODULATION
    Publication number: 20130286802
    Abstract: A transducer comprises a slider and a laser arrangement. The laser arrangement is configured to heat a region of a magnetic medium in proximity to the slider and produce modulated laser light to cause heat-induced modulation of the slider. The laser arrangement is configured to couple laser light at a power that reduces a coercivity of magnetic material at the region for writing data to or erasing data at the region, and couple modulated laser light to cause heat-induced modulation of the slider at a power lower than the power for writing data to or erasing data at the magnetic medium.
    Type: Application
    Filed: March 11, 2013
    Publication date: October 31, 2013
    Applicant: Seagate Technology LLC
    Inventor: James Dillon Kiely
  • Read channel averaging
    Patent number: 8570679
    Abstract: A hard disk drive with a read channel that averages data before the data is provided to a viterbi detector of the channel. Averaging the data reduces the zero mean noise in the data.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: October 29, 2013
    Assignee: Seagate Technology International
    Inventors: Yunxiang Wu, Henry Bang, Richard Wang