Patents Examined by Nabil Z. Hindi
  • Patent number: 11562767
    Abstract: An integrated circuit includes a read/write channel and a servo controller. The read/write channel is configured to: determine, in connection with a first path, respective read errors associated with N number of the data sectors; estimate respective offset positions of the N number of the data sectors; and generate a second path based, at least in part, on the respective estimated offset positions. The servo controller is configured to cause adjustment of a position of a read transducer based on the second path.
    Type: Grant
    Filed: September 8, 2021
    Date of Patent: January 24, 2023
    Assignee: Seagate Technology LLC
    Inventors: Ara Patapoutian, Jason Bellorado, Zheng Wang, William M. Radich
  • Patent number: 11557316
    Abstract: The present disclosure describes aspects of pulse-based writing for magnetic storage media. In some aspects, a pulse-based writer of magnetic storage media determines that a string of data bits having a same polarity corresponds to a magnet longer than a threshold associated with a magnetic media writer. The pulse-based writer inserts, into the string of data bits, a transition to a polarity opposite to the same polarity of the string of data bits. The string of data bits including the inserted transition is then transmitted to the magnetic media writer to cause a write head of the writer to pulse while writing the magnet to magnetic storage media. Various aspects may also implement a control signal to mask a transition or control polarity of the magnetic media writer. By so doing, magnets may be written to the magnetic storage media more efficiently or with less distortion to neighboring tracks.
    Type: Grant
    Filed: March 3, 2022
    Date of Patent: January 17, 2023
    Assignee: Marvell Asia PTE Ltd.
    Inventors: Mats Oberg, Hao Fang
  • Patent number: 11557313
    Abstract: According to one embodiment, a magnetic disk device includes a first disk including a first data sector, a second disk including a second data sector, a first head including a first read head, a second head including a second read head, a first controller that stops write operations of both the first head and the second head based on first data sector position error information obtained by reading and demodulating the first data sector by using the first read head, and a second controller that stops the write operations of both the first head and the second head based on second data sector position error information obtained by reading and demodulating the second data sector by using the second read head.
    Type: Grant
    Filed: January 27, 2022
    Date of Patent: January 17, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Daisuke Sudo
  • Patent number: 11557312
    Abstract: According to one embodiment, a magnetic disk device includes a first disk, the second disk, and a first head which writes and reads to the first disk, a second head which writes and reads to the second disk, and a controller which calculates an estimated position at which the second head is estimated to be disposed on the second disk based on first relative position information related to a relative position in a radial direction between the first head and the second head when the first head is switched to the second head.
    Type: Grant
    Filed: September 2, 2021
    Date of Patent: January 17, 2023
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Daisuke Sudo, Takeyori Hara
  • Patent number: 11551710
    Abstract: According to an embodiment, a magnetic disk has a plurality of second servo sectors and a plurality of third servo sectors each arranged between two second servo sectors of the plurality of second servo sectors, in which the second and third servo sectors are arranged in a circumferential direction. A controller performs a first demodulation for detecting a servo mark and demodulating a burst pattern on the servo data in each second servo sector. The controller performs a second demodulation for demodulating the burst pattern without detecting the servo mark, on the servo data in each third servo sector. The controller performs the second demodulation on the servo data in a fourth servo sector which is one of the plurality of second servo sectors in a case where the detection of the servo mark fails when the first demodulation is performed on the servo data in the fourth servo sector.
    Type: Grant
    Filed: February 23, 2022
    Date of Patent: January 10, 2023
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
    Inventor: Yoshifumi Obara
  • Patent number: 11551718
    Abstract: A recording and reproducing device includes: a reading unit that reads production information from a recording medium of a magnetic tape cartridge, the magnetic tape cartridge including a magnetic tape, and the recording medium other than the magnetic tape and on which the production information is recorded, the production information being information regarding the magnetic tape obtained in a production process of the magnetic tape cartridge; and a control unit that performs, as an initialization process of the magnetic tape cartridge, control of recording the production information on the magnetic tape and invalidating the production information in the recording medium.
    Type: Grant
    Filed: July 13, 2021
    Date of Patent: January 10, 2023
    Assignee: FUJIFILM CORPORATION
    Inventors: Toru Nakao, Hodaka Suzuki, Yoichi Akano
  • Patent number: 11545176
    Abstract: A magnetic recording medium includes a substrate, and a magnetic recording layer including magnetic grains having an L10 structure. The magnetic recording layer is (001) oriented, and a surface of growth of the magnetic recording layer includes a (001) plane, a (111) plane, and planes equivalent to the (111) plane. An area ratio of the (111) plane and the planes equivalent to the (111) plane, represented by (A111+A111e)/(A001+A111+A111e), is in a range of 0.2 to 0.7, where A111 denotes an area of the (111) plane, A111e denotes an area of the planes equivalent to the (111) plane, and A001 denotes an area of the (001) plane.
    Type: Grant
    Filed: April 5, 2022
    Date of Patent: January 3, 2023
    Assignee: SHOWA DENKO K.K.
    Inventors: Takayuki Fukushima, Tomoo Shige, Yuji Umemoto, Kazuya Niwa
  • Patent number: 11531582
    Abstract: A data storage device is disclosed comprising a non-volatile storage medium (NVSM) having a plurality of data sectors and a plurality of reserve sectors. A map-out value is generated for each of a first plurality of the data sectors based on a read latency of each of the first plurality of data sectors, and when the map-out value of a first data sector in the first plurality of data sectors exceeds a threshold, a first logical block address (LBA) is mapped from the first data sector to a first reserve sector. When the map-out value of a second data sector in the first plurality of data sectors exceeds the map-out value of the first data sector, the first LBA is mapped from the first reserve sector back to the first data sector, and a second LBA is mapped from the second data sector to the first reserve sector.
    Type: Grant
    Filed: July 22, 2020
    Date of Patent: December 20, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Bernd Lamberts, Remmelt Pit, Abhishek Srivastava, Karthik Venkatesh, Ammar A. Zayed
  • Patent number: 11532331
    Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, a heater a control section. When making the magnetic head carry out the seek operation from the first position to the second position, the control section starts application of a first voltage to the heater while the seek operation is carried out and, after application of the first voltage, makes the voltage to be applied to the heater a second voltage greater than the first voltage before the magnetic head is positioned to the second position and write of data is started by the magnetic head.
    Type: Grant
    Filed: August 12, 2021
    Date of Patent: December 20, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Masami Yamane
  • Patent number: 11532320
    Abstract: The present disclosure generally relates to a tape head and a tape drive including a tape head. The tape head comprises a first same gap verify (SGV) head assembly comprising a first media facing surface (MFS) and a plurality of first write transducer and first read transducer pairs, and a second SGV head assembly comprising a second MFS and a plurality of second write transducer and second read transducer pairs. During operation, when a tape or magnetic media moves in a first direction over the tape head, the tape contacts the second MFS and is spaced from the first MFS, and when the tape moves in a second direction opposite the first direction over the tape head, the tape contacts the first MFS and is spaced from the second MFS. As such, the tape contacts only one edge of either the first or second MFS during operation.
    Type: Grant
    Filed: October 27, 2021
    Date of Patent: December 20, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Robert G. Biskeborn, Oscar J. Ruiz
  • Patent number: 11532321
    Abstract: According to one embodiment, a magnetic disk device including a disk, a head that writes data with respect to the disk and reads data from the disk, and a controller that overwrites a second track on a first track in a radial direction of the disk, performs first alternative processing of recording a first user sector in a first region when writing of the first user sector available by a user in the first track is disabled, and performs second alternative processing different from the first alternative processing of recording a first parity sector in a second region when writing of the first parity sector acquired by an XOR operation in the first track is disabled.
    Type: Grant
    Filed: January 28, 2022
    Date of Patent: December 20, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Nobuhiro Maeto
  • Patent number: 11532322
    Abstract: The presently disclosed technology teaches integrating disc drive electronics into a transducer head. Decreased electrical transit times and data processing times can be achieved by placing the electronics on or within the transducer head because electrical connections may be made physically shorter than in conventional systems. The electronics may include one or more of a control system circuit, a write driver, and/or a data buffer. The control system circuit generates a modified clock signal that has a fixed relation to phase and frequency of a bit-detected reference signal that corresponds to positions of patterned bits on the disc. The write driver writes outgoing data bits received from an external connection to off-head electronics directly to the writer synchronized with the modified clock signal. The data buffer stores and converts digital data bits sent from the off-head electronics to an analog signal that is synchronized with the modified clock signal.
    Type: Grant
    Filed: October 22, 2021
    Date of Patent: December 20, 2022
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Mark Anthony Gubbins, Robert William Lamberton, Robert Edward Weinstein, James Joseph Touchton
  • Patent number: 11532329
    Abstract: A heat-assisted magnetic recording (HAMR) head has a slider with a gas-bearing-surface (GBS). The slider supports a near-field transducer (NFT) and a main magnetic pole that has a step or recess in the NFT-facing surface near the GBS that contains plasmonic material. A thermal shunt is located between the NFT and the main pole to allow heat to be transferred away from the optical spot generated by the NFT. The NFT-facing surface of the main pole that is recessed from the step away from the GBS is in contact with the thermal shunt, and the thermal shunt is in contact with the plasmonic material in the step in the back region recessed from the GBS, so there is no increase in the spacing between the NFT and a large portion of the main pole.
    Type: Grant
    Filed: January 31, 2022
    Date of Patent: December 20, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Takuya Matsumoto, Barry Cushing Stipe, Muhammad Asif Bashir
  • Patent number: 11521647
    Abstract: A controller for a magnetic disk device acquires a reproduction signal of servo burst data while moving a magnetic head along data tracks that intersect servo tracks at a plurality of points. The controller acquires correction values for correcting repeatable runout on a per servo sector basis based on the reproduction signal. The correction values include a first correction value, which is a correction value for a servo sector at a position where the data track and the servo track are substantially parallel to each other and a second correction value, which is a correction value fora servo sector at a position where the data track and the servo track are not substantially parallel to each other. The controller adjusts the first correction value based on the second correction value, and writes the correction values including the adjusted first correction value onto a magnetic disk.
    Type: Grant
    Filed: August 30, 2021
    Date of Patent: December 6, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Takuya Ogawa, Shinichirou Kouhara, Wataru Tsukahara
  • Patent number: 11521644
    Abstract: According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the second magnetic pole and the first magnetic layer, a third magnetic layer provided between the second magnetic pole and the second magnetic layer, a fourth magnetic layer provided between the second magnetic pole and the third magnetic layer, a first non-magnetic layer provided between the first magnetic layer and the first magnetic pole, a second non-magnetic layer provided between the second and first magnetic layers, a third non-magnetic layer provided between the third and second magnetic layers, a fourth non-magnetic layer provided between the fourth magnetic layer and the third magnetic layer, and a fifth non-magnetic layer provided between the second magnetic pole and the fourth magnetic layer.
    Type: Grant
    Filed: August 9, 2021
    Date of Patent: December 6, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventors: Yuji Nakagawa, Naoyuki Narita, Masayuki Takagishi, Tomoyuki Maeda, Tazumi Nagasawa, Hirofumi Suto
  • Patent number: 11514939
    Abstract: A victim feedforward signal is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator, where the victim feedforward signal is configured to compensate for disturbances to a victim head caused by assertion of the aggressor VCM control signal. Each aggressor VCM control signal is asserted at a specific time by the aggressor actuator, for example in response to the aggressor head passing over a first servo wedge. A feedforward signal that compensates for the effect of the aggressor VCM control signal is then determined based on the aggressor VCM control signal, stored, and asserted via the victim microactuator at a predetermined time relative to when the aggressor VCM control signal is asserted.
    Type: Grant
    Filed: November 24, 2021
    Date of Patent: November 29, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Richard M. Ehrlich
  • Patent number: 11514946
    Abstract: A heat-assisted magnetic recording (HAMR) disk drive uses a semiconductor laser mounted on a slider to deliver light to a near-field transducer (NFT) via a waveguide located inside the slider. The waveguide includes a core and cladding material that is transparent to the laser light and surrounds the core. Layers of stray light absorption material are located inside the slider on opposite edges of the waveguide core in the same plane as the core and on opposite sides of the waveguide core in planes spaced from the plane of the core. Portions of the waveguide cladding material are located between the waveguide core and the stray light absorption layers. The stray light absorption layers absorb light that leaks into the cladding material and substantially reduces stray light reflected to the laser to prevent undesirable laser power fluctuation.
    Type: Grant
    Filed: November 9, 2021
    Date of Patent: November 29, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Norman Shi, Takuya Matsumoto, Barry Cushing Stipe
  • Patent number: 11508399
    Abstract: According to one embodiment, a magnetic disk device includes a disk, a head, and a controller setting a rewrite threshold value for executing a rewrite process of different tracks in a first sector group including at least one first sector continuous from a first parity sector in which error correction processing in units of tracks is executable based on the first parity sector and including the first parity sector, and a second sector group including at least one second sector continuous in which the error correction processing in units of tracks is unexecutable, and rewriting the first sector group and the second sector group with different frequencies.
    Type: Grant
    Filed: August 20, 2021
    Date of Patent: November 22, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Nobuhiro Maeto
  • Patent number: 11508405
    Abstract: Magnetic recording media including a soft magnetic underlayer (SUL) formed over a plasma-polished substrate or pre-seed layer. In some examples, the substrate or pre-seed layer is plasma-polished using an inert gas such as krypton so that the roughness of the surface on which the SUL is deposited is reduced. The roughness reduction can lead to improved crystallographic texture within subsequently deposited media films, and consequently, to increased recording performance of the media. In particular, media signal-to-noise ratio (SNR), linear recording density, and areal recording density or areal density capacity (ADC) can be improved. In one aspect, a carbon deposition/etching apparatus may be modified to polish the substrate or pre-seed layer with krypton or other inert gases, rather than be used to deposit carbon overcoat.
    Type: Grant
    Filed: June 21, 2021
    Date of Patent: November 22, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventor: Kai Tang
  • Patent number: 11508398
    Abstract: According to one embodiment, a magnetic disk device includes a magnetic disk, a head and a controller. The head writes data to the magnetic disk and reads data from the magnetic disk. The controller once reads the data written to a predetermined recording area according to the number of writes of data to the predetermined recording area of the magnetic disk and rewrites the read data to the predetermined recording area. The controller adjusts an additive value to the number of writes based on the presence or absence of a defect on the recording surface of the magnetic disk.
    Type: Grant
    Filed: July 27, 2021
    Date of Patent: November 22, 2022
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Takeshi Shibasaki