Patents Examined by Thomas Alunkal
  • Selective interfacing apparatus and method
    Patent number: 9235351
    Abstract: An optical disc drive, and a method of driving the optical disc drive are provided. Where the optical disc drive has a connectivity or a compatibility with a host that is incompatible with the optical disc drive, a file system and device information accepted by the host are provided. The host may have a compatibility with limited external medium devices and a specific command set for data exchange. The optical disc drive and the method of driving the optical disc drive may transmit compatible information to the host and select the specific command set accepted by the host, so that the optical disc drive is compatible with the host.
    Type: Grant
    Filed: June 24, 2010
    Date of Patent: January 12, 2016
    Assignee: Toshiba Samsung Storage Technology Korea Corporation
    Inventors: Soon-gyu Jeong, Dong-hwan Lim, Hyung-kyoon Kim, Dong-jin Lee, Chang-heon Kim, Won Kim
  • Dynamic adjustments of tape head wrap angles
    Patent number: 9230590
    Abstract: Embodiments of the present invention provide tape drives and methods for operating a tape drive. In one embodiment, tape head wrap angles are dynamically adjusted to increase or decrease contact pressure of magnetic tape on modules of a tape head. Embodiments of the present invention can be used to extend the lifespan of tape drives and components, and enable usage of tape media having increased smoothness and areal density.
    Type: Grant
    Filed: December 11, 2014
    Date of Patent: January 5, 2016
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Jason Liang
  • Non-decision directed magnetoresistive asymetry estimation
    Patent number: 9224421
    Abstract: Systems and methods for magnetoresistive asymmetry estimation may include, but are not limited to, operations for: receiving a magnetic read head transducer output; computing a mean value of the magnetic read head transducer output; computing a median value of the magnetic read head transducer output; and applying a correction coefficient to a magnetic read head detector input according to at least the mean value of the magnetic read head transducer output and the median value of the magnetic read head transducer output.
    Type: Grant
    Filed: March 7, 2014
    Date of Patent: December 29, 2015
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventors: Bruce A. Wilson, Nayak Ratnakar Aravind, Haitao Xia
  • Compensating for voice coil motor and microactuator disturbance in a hard drive
    Patent number: 9202496
    Abstract: In response to positioning a read/write head of a hard drive, a voice coil motor (VCM) input signal is applied to a voice coil motor and a microactuator (PZT) input signal is applied to a microactuator. A position signal is determined in response to positioning the read/write head. A PZT component is decoupled from the position signal to determine an estimated VCM response. The estimated VCM response used to determine an estimated VCM disturbance. A VCM component is decoupled from the position signal to determine an estimated PZT response. The estimated PZT response used to determine an estimated PZT disturbance. The VCM input signal and the PZT input signal are modified respectively to compensate for the estimated VCM disturbance and the estimated PZT disturbance.
    Type: Grant
    Filed: February 25, 2014
    Date of Patent: December 1, 2015
    Assignee: Seagate Technology LLC
    Inventor: Lou Supino
  • Light source alignment for heat assisted magnetic recording
    Patent number: 9202487
    Abstract: An approach for aligning a light source on a slider involves filtering light emerging from the air bearing surface of a (ABS) of a heat assisted magnetic recording (HAMR) slider. A first portion of the emerging light is emitted by a near field transducer in response to optical excitation and has a component having a first polarization state. A second portion of the emerging light including stray light has polarization states different from the first polarization state. The polarizing filter substantially transmits light having the first polarization state and substantially rejects light having a polarization state orthogonal to the first polarization state. Alignment coordinates for the light source are determined based on the light transmitted through the polarizing filter.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: December 1, 2015
    Assignee: Seagate Technology LLC
    Inventor: Chubing Peng
  • Logging disk recovery operations in a non-volatile solid-state memory cache
    Patent number: 9177607
    Abstract: An apparatus includes a controller capable of being coupled to a magnetic data storage media and a cache. The cache includes non-volatile, solid-state memory. The controller is configured to detect a defect in the data storage media requiring a recovery operation and allocate a portion of the cache for storage of a journal to be used in the recovery operation. The controller is further configured to log steps of the recovery operation to the journal.
    Type: Grant
    Filed: May 16, 2012
    Date of Patent: November 3, 2015
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Yunaldi Yulizar, Akhila Tadinada
  • Operational amplifier, motor drive device, magnetic disk storage device, and electronic appliance
    Patent number: 9160270
    Abstract: An operational amplifier has an input stage which generates a first input current and a second input current in accordance with a first input signal and a second input signal, an offset adjuster which gives offsets to the first input current and the second input current respectively to generate a first output current and a second output current, an output stage which generates an output signal in accordance with the first output current and the second output current, and an offset current generator which generates a first offset current and a second offset current in accordance with an offset adjustment signal. The offset adjuster gives the offsets to the first input current and the second input current respectively by using the first offset current and the second offset current.
    Type: Grant
    Filed: May 15, 2013
    Date of Patent: October 13, 2015
    Assignee: ROHM CO., LTD.
    Inventor: Shinichi Miura
  • Optical disc device
    Patent number: 9153271
    Abstract: The optical disc device has a circuit which forms a focus error signal for focus servo control based on reflection light from an optical disc exposed to laser light. Also, the device has a data processing unit which can control by feedback a position to which an objective lens is moved by a focusing actuator based on a focus error signal. In label printing, the data processing unit controls, by feedforward, a position to which the objective lens is moved by the focusing actuator based on control data for label printing. The operation resolution of the focusing actuator in feedforward control is made higher than that in feedback control. Thus, an intended position control accuracy is achieved in feedforward control. For instance, in feedforward control, the gain of the driver circuit for the focusing actuator is switched to a smaller one in comparison to that in feedback control.
    Type: Grant
    Filed: June 6, 2014
    Date of Patent: October 6, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Yoshimi Iso, Mitsuo Hagiwara, Mitsuyuki Kimura
  • Optical pickup and optical information storage system including the same
    Patent number: 9147426
    Abstract: Provided are an optical pickup and an optical information storage system including the same. The optical pickup includes a diffracting element that splits incident light into main light and a plurality of sub light. The diffracting element has at least three regions including first through third regions. A second region is disposed between a first region and a third region and has a phase difference from the first and third regions. The optical pickup detects a tracking error signal by using light diffracted by the diffracting element.
    Type: Grant
    Filed: February 25, 2014
    Date of Patent: September 29, 2015
    Assignee: Toshiba Samsung Storage Technology Korea Corporation
    Inventors: Ki-bok Kim, Ji-sun Ahn, Ju-hee Im, Jin-ho Jeong, Seung-man Han
  • Optical pickup and optical information storage system including the same
    Patent number: 9142243
    Abstract: Provided are an optical pickup and an optical information storage system including the same. The optical pickup includes a photodetector that receives a main light beam and a plurality of sub-light beams reflected from an information storage medium and diffracted by a diffracting element. The photo detector detects a tracking error signal using zeroth-order light as the main light beam and using one of first-order light and third-order light as the sub-light beam based on a type of an optical information storage medium.
    Type: Grant
    Filed: February 24, 2014
    Date of Patent: September 22, 2015
    Assignee: Toshiba Samsung Storage Technology Korea Corporation
    Inventors: Ki-bok Kim, Jin-ho Jeong, Eun-goo Kim, Jung-bae Oh, Seung-man Han
  • Heat assisted magnetic recording writer having a recessed pole
    Patent number: 9142233
    Abstract: A heat assisted magnetic recording (HAMR) write transducer has an air-bearing surface (ABS) configured to reside in proximity to a media during use and is coupled with a laser that provides energy. The HAMR transducer includes a main pole, at least one additional pole adjacent to the main pole in a down track direction, a waveguide and at least one coil for energizing the main pole. The main pole is configured to write to a region of the media and is recessed from the ABS by a first distance. The additional pole(s) are recessed from the ABS by a second distance greater than the first distance. The waveguide is optically coupled with the laser and directs a portion of the energy toward the ABS at an acute angle from the ABS. A portion of the waveguide resides between the additional pole(s) and the ABS.
    Type: Grant
    Filed: June 6, 2014
    Date of Patent: September 22, 2015
    Assignee: Western Digital (Fremont), LLC
    Inventors: Matthew R. Gibbons, Hongxing Yuan, Brad V. Johnson, Michael V. Morelli, Lisha Wang, Zhigang Bai, Ge Yi, Yunfei Li, Samuel W. Yuan
  • Disk drive using timing loop control signal for vibration compensation in servo loop
    Patent number: 9142249
    Abstract: A disk drive is disclosed comprising a timing loop configured to generate a clock synchronized to a rotation of a disk and a servo loop configured to control an actuator to actuate a head over the disk. A timing signal generated by the timing loop is filtered with a pre-compensation filter (PCF) comprising an inverse transfer function from a delta in a rotation velocity of the disk (??) due to a vibration affecting the disk drive to the timing signal, and the actuator is controlled to actuate the head over the disk based on an output of the PCF.
    Type: Grant
    Filed: December 6, 2013
    Date of Patent: September 22, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Jianguo Zhou, Guoxiao Guo, Donald Brunnett, Min Chen, Wei Guo, Jie Yu
  • Servo channel with equalizer adaptation
    Patent number: 9129647
    Abstract: A servo system includes an equalizer circuit operable to filter digital servo data samples according to filter tap coefficients to yield equalized data, a detector circuit operable to apply a data detection algorithm to the equalized data to yield hard decisions, a convolution circuit operable to yield ideal digital data based on the hard decisions and on target values, a subtraction circuit operable to subtract the ideal digital data from the equalized data to yield an adaptation error signal, an error gradient calculator operable calculate an error gradient signal based at least in part on the adaptation error signal, and a tap adaptation circuit operable to calculate values of the filter tap coefficients based on the error gradient signal.
    Type: Grant
    Filed: December 20, 2013
    Date of Patent: September 8, 2015
    Assignee: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
    Inventors: Yu Liao, Xun Zhang, Haitao Xia
  • Data storage device employing full servo sectors on first disk surface and mini servo sectors on second disk surface
    Patent number: 9129630
    Abstract: A data storage device is disclosed comprising a first head actuated over a first disk surface comprising servo tracks defined by full servo sectors, and a second head actuated over a second disk surface comprising servo tracks defined by mini servo sectors. At least part of a track address is read from one of the full servo sectors to generate at least one high order bit of a full track address, and at least part of a track address is read from one of the mini servo sectors to generate at least one low order bit of the full track address. The high order bit and the low order bit are combined to generate at least part of the full track address, and during an access of the second disk surface, the second head is servoed over the second disk surface based on the full track address.
    Type: Grant
    Filed: December 16, 2014
    Date of Patent: September 8, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Wei Guo, Michael Chang, Yuan Chen
  • CPP-type magnetoresistance effect element and magnetic disk device
    Patent number: 9129622
    Abstract: A magnetoresistive effect element that prevents a recording medium from deteriorating by effectively inhibiting erroneous writing to a medium or the like includes a magnetoresistive effect part, and an upper shield layer and a lower shield layer that are laminated and formed in a manner sandwiching the magnetoresistive effect part from above and below, and is in a current perpendicular to plane (CPP) structure in which a sense current is applied in a lamination direction.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: September 8, 2015
    Assignee: TDK Corporation
    Inventors: Takahiko Machita, Naomichi Degawa, Takekazu Yamane, Takumi Yanagisawa, Satoshi Miura, Kenta Hamamoto, Minoru Ota, Kenzo Makino, Shohei Kawasaki
  • Detecting track information from overlapping signals read from a data storage medium
    Patent number: 9123356
    Abstract: Detecting track information involves receiving first and second overlapping track signals from first and second read elements that read first and second tracks from a data storage medium. Information of the first and second tracks is estimated using the respective first and second track signals. An improved information estimate of the first track is obtained using the first track signal and the estimated information of the second track, and an improved information estimate of the second track is obtained using the second track signal and the estimated information of the first track. First and second track data are decoded using the respective improved information estimates of the first and second tracks.
    Type: Grant
    Filed: December 12, 2012
    Date of Patent: September 1, 2015
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Sundararajan Sankaranarayanan, Raman Venkataranmani, William Michael Radich
  • Data storage system and a method for measuring a change in a spacing between a head and a storage medium of a data storage system
    Patent number: 9123386
    Abstract: A method for measuring a change in a spacing between a head and a storage medium of a data storage system. The method includes obtaining a first readback signal from the storage medium using the head at a first spacing between the head and the storage medium, determining a first power spectrum density over a frequency range from the obtained first readback signal, obtaining a second readback signal from the storage medium using the head at a second spacing between the head and the storage medium, determining a second power spectrum density over the frequency range from the obtained second readback signal, and providing a measurement indicative of the change in the spacing based on the determined first power spectrum density and the determined second power spectrum density. A data storage system is also provided.
    Type: Grant
    Filed: November 1, 2012
    Date of Patent: September 1, 2015
    Assignee: Agency for Science, Technology and Research
    Inventors: Zhimin Yuan, Bo Liu, Shengbin Hu, Chun Lian Ong
  • Data storage device erasing multiple adjacent data tracks to recover from inter-track interference
    Patent number: 9117463
    Abstract: A data storage device is disclosed comprising a disk comprising a plurality of data tracks, and a head actuated over the disk. A retry operation for a target data track is performed by positioning the head at a first radial location and first erasing at least part of a first data track adjacent the target data track. After the first erasing, the target data track is first read to first recover target data recorded in the target data track. When the first recovery fails, the head is positioned at a second radial location and more of the first data track is second erased. After the second erasing, the target data track is second read to second recover the target data recorded in the target data track.
    Type: Grant
    Filed: June 23, 2014
    Date of Patent: August 25, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Kathy X. Tang, Jerry G. Le
  • Systems and methods for loop feedback
    Patent number: 9112538
    Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for performing loop feedback in a data processing system.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: August 18, 2015
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventors: Jianzhong Huang, Yu Kou, Haitao Xia, Seongwook Jeong
  • System and method for providing controllable steady state current waveshaping in a hard disk drive (HDD) preamplifier
    Patent number: 9105276
    Abstract: Aspects of the disclosure pertain to a system and method for providing controllable steady state current waveshaping in a preamplifier of a data storage system (e.g., hard disk drive). The preamplifier provides an output including a write current waveform having a steady state current level that is controllable via the write block circuitry of the preamplifier. This enhances the ability of the waveform to promote improved on-track and off-track write performance.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: August 11, 2015
    Assignee: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
    Inventors: Boris Livshitz, Anamul Hoque, Jason Goldberg