Patents by Inventor Hisashi Takano

Hisashi Takano 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).

  • Publication number: 20230121375
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) devices comprising a topological insulator (TI) modulation layer. The TI modulation layer comprises a plurality of bismuth or bismuth-rich composition modulation layers, a plurality of TI lamellae layers comprising BiSb having a (012) crystal orientation, and a plurality of texturing layers. The TI lamellae layers comprise dopants or clusters of atoms, the clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material. The clusters of atoms are configured to have a grain boundary glass forming temperature of less than about 400° C. Doping the TI lamellae layers comprising BiSb having a (012) crystal orientation with clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material enable the SOT MTJ device to operate at higher temperatures while inhibiting migration of Sb from the BiSb of the TI lamellae layers.
    Type: Application
    Filed: December 16, 2022
    Publication date: April 20, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Brian R. YORK, Cherngye HWANG, Susumu OKAMURA, Xiaoyong LIU, Kuok San HO, Hisashi TAKANO
  • Patent number: 11615809
    Abstract: The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device that comprises a first shield, a first spin hall effect layer, a first free layer, a gap layer, a second spin hall effect layer, a second free layer, and a second shield. The gap layer is disposed between the first spin hall effect layer and the second spin hall effect layer. Electrical lead connections are located about the first spin hall effect layer, the second spin hall effect layer, the gap layer, the first shield, and/or the second shield. The electrical lead connections facilitate the flow of current and/or voltage from a negative lead to a positive lead. The positioning of the electrical lead connections and the positioning of the SOT differential layers improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
    Type: Grant
    Filed: August 5, 2021
    Date of Patent: March 28, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Xiaoyong Liu, Zhigang Bai, Zhanjie Li, Kuok San Ho, Hisashi Takano
  • Publication number: 20230047223
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a buffer layer, a bismuth antimony (BiSb) layer having a (012) orientation disposed on the buffer layer, and an interlayer disposed on the BiSb layer. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer each comprise at least one of a covalently bonded amorphous material, a tetragonal (001) material, a tetragonal (110) material, a body-centered cubic (bcc) (100) material, a face-centered cubic (fcc) (100) material, a textured bcc (100) material, a textured fcc (100) material, a textured (100) material, or an amorphous metallic material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the BiSb layer and enhance uniformity of the BiSb layer while further promoting the (012) orientation of the BiSb layer.
    Type: Application
    Filed: August 13, 2021
    Publication date: February 16, 2023
    Inventors: Quang LE, Brian R. YORK, Cherngye HWANG, Susumu OKAMURA, Michael GRIBELYUK, Xiaoyong LIU, Kuok San HO, Hisashi TAKANO
  • Publication number: 20230040698
    Abstract: The present disclosure generally relates to a tape drive including a tape head. The tape head comprises at least one same gap verify (SGV) module comprising a plurality of write transducer and read transducer pairs disposed on a substrate. Each pair comprises a null shield disposed between the write transducer and the read transducer. The null shield is used to create a null region, or a region where write flux goes to zero, and comprises laminated antiferromagnetic coupling materials to protect writer flux from going to the read transducer. The read transducer is disposed in the null region. The SGV module is configured to write data to a tape using the write transducer of each pair and read verify the data written on the tape using the read transducer of each pair such that the write transducer and read transducer of each pair are concurrently operable.
    Type: Application
    Filed: August 6, 2021
    Publication date: February 9, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Xiaoyong LIU, Kuok San HO, Hisashi TAKANO
  • Publication number: 20220415345
    Abstract: The present disclosure relates to read head apparatus, and methods of forming read head apparatus, for magnetic storage devices, such as magnetic tape drives (e.g., tape drives). In one implementation, a read head for magnetic storage devices includes a lower shield, one or more upper shields, one or more lower leads, and a plurality of upper leads. The read head includes a plurality of read sensors, each read sensor of the plurality of read sensors including a first antiferromagnetic (AFM) layer. The read head includes a plurality of soft bias side shields disposed between and outwardly of the plurality of read sensors. The read head includes one or more second AFM layers disposed above the first AFM layer and the plurality of soft bias side shields along a downtrack direction.
    Type: Application
    Filed: July 18, 2022
    Publication date: December 29, 2022
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Hongquan JIANG, Cherngye HWANG, Hisashi TAKANO
  • Patent number: 11532323
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a topological insulator (TI) modulation layer. The TI modulation layer comprises a plurality of bismuth or bismuth-rich composition modulation layers, a plurality of TI lamellae layers comprising BiSb having a (012) crystal orientation, and a plurality of texturing layers. The TI lamellae layers comprise dopants or clusters of atoms, the clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material. The clusters of atoms are configured to have a grain boundary glass forming temperature of less than about 400° C. Doping the TI lamellae layers comprising BiSb having a (012) crystal orientation with clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material enable the SOT MTJ device to operate at higher temperatures while inhibiting migration of Sb from the BiSb of the TI lamellae layers.
    Type: Grant
    Filed: August 18, 2021
    Date of Patent: December 20, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Brian R. York, Cherngye Hwang, Susumu Okamura, Xiaoyong Liu, Kuok San Ho, Hisashi Takano
  • Patent number: 11532325
    Abstract: The present disclosure is generally related to a tape drive including a tape head configured to read shingled data tracks on a tape. The tape head comprises a first module head assembly aligned with a second module head assembly. Both the first and second module head assemblies comprises one or more servo heads and a plurality of data heads. Each data head comprises a write head, a first read head aligned with the write head, and a second read head offset from the first read head in both a cross-track direction and a down-track direction. The first read heads and the second read heads are configured to read data from a shingled data track of the tape simultaneously. In some embodiments, the tape head is able to be dynamically tilted in order to tilt the first and second reads heads when reading curved portions of shingled data tracks.
    Type: Grant
    Filed: December 15, 2021
    Date of Patent: December 20, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Xiaoyong Liu, Zhigang Bai, Kuok San Ho, Hisashi Takano
  • Patent number: 11514930
    Abstract: The present disclosure generally relates to magnetic storage devices, such as magnetic tape drives, comprising a read head. The read head comprises a plurality of read sensors disposed between a lower shield and an upper shield. A plurality of soft bias side shields are disposed adjacent to and outwardly of the plurality of read sensors in a cross-track direction. A plurality of hard bias side shields are disposed on and in contact with the soft bias side shields to stabilize the soft bias side shields. Each of the plurality of soft bias side shields are spaced a first distance from the lower shield and each of the hard bias side shields are spaced a second distance from the upper shield, the first distance being substantially equal to the second distance.
    Type: Grant
    Filed: June 25, 2021
    Date of Patent: November 29, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Hongquan Jiang, Hisashi Takano, Cherngye Hwang
  • Patent number: 11514932
    Abstract: The present disclosure generally relates to magnetic storage devices, such as magnetic tape drives, comprising a read head. The read head comprises a plurality of read sensors disposed between a lower shield having a first width in a stripe height direction and an upper shield. The plurality of read sensors comprise an antiferromagnetic layer and a free layer comprising a first layer and a second layer. A plurality of soft bias side shields disposed adjacent to and outwardly of the plurality of read sensors in a cross-track direction, each of the plurality of soft bias side shields having a second width in the stripe height direction less than the first width. Each of the plurality of soft bias side shields are spaced a first distance from the lower shield and a second distance from the upper shield, the first distance being substantially equal to the second distance.
    Type: Grant
    Filed: June 25, 2021
    Date of Patent: November 29, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Hongquan Jiang, Hisashi Takano, Cherngye Hwang, Xiaoyong Liu
  • Patent number: 11514936
    Abstract: The present disclosure relates to read head apparatus, and methods of forming read head apparatus, for magnetic storage devices, such as magnetic tape drives (e.g., tape drives). In one implementation, a read head for magnetic storage devices includes a lower shield, an upper shield, one or more lower leads, and a plurality of upper leads. The read head includes a plurality of read sensors, each read sensor of the plurality of read sensors including a first antiferromagnetic (AFM) layer. The read head includes a plurality of soft bias side shields disposed between and outwardly of the plurality of read sensors. The read head includes a plurality of second AFM layers disposed below the plurality of soft bias side shields along a downtrack direction.
    Type: Grant
    Filed: June 25, 2021
    Date of Patent: November 29, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Hongquan Jiang, Cherngye Hwang, Hisashi Takano
  • Patent number: 11437061
    Abstract: The present disclosure relates to read head apparatus, and methods of forming read head apparatus, for magnetic storage devices, such as magnetic tape drives (e.g., tape drives). In one implementation, a read head for magnetic storage devices includes a lower shield, one or more upper shields, one or more lower leads, and a plurality of upper leads. The read head includes a plurality of read sensors, each read sensor of the plurality of read sensors including a first antiferromagnetic (AFM) layer. The read head includes a plurality of soft bias side shields disposed between and outwardly of the plurality of read sensors. The read head includes one or more second AFM layers disposed above the first AFM layer and the plurality of soft bias side shields along a downtrack direction.
    Type: Grant
    Filed: June 25, 2021
    Date of Patent: September 6, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Hongquan Jiang, Cherngye Hwang, Hisashi Takano
  • Publication number: 20220013139
    Abstract: The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device that comprises a first shield, a first spin hall layer, a first free layer, a gap layer, a second spin hall layer, a second free layer, and a second shield. The gap layer functions as an electrode and is disposed between the first spin hall layer and the second spin hall layer. Electrical lead connections are located about the first spin hall layer, the second spin hall layer, the gap layer, the first shield, and/or the second shield. The electrical lead connections facilitate the flow of current and/or voltage from a negative lead to a positive lead. The positioning of the electrical lead connections and the positioning of the SOT differential layers improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
    Type: Application
    Filed: September 23, 2020
    Publication date: January 13, 2022
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Xiaoyong LIU, Zhigang BAI, Zhanjie LI, Kuok San HO, Hisashi TAKANO
  • Publication number: 20220013138
    Abstract: The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device comprising a first seed layer, a first spin hall effect (SHE) layer, a first interlayer, a first free layer, a gap layer, a second seed layer, a second SHE layer, a second free layer, and a second interlayer. The gap layer is disposed between the first SHE layer and the second SHE layer. The materials and dimensions used for the first and second seed layers, the first and second interlayers, and the first and second SHE layers affect the resulting spin hall voltage converted from spin current injected from the first free layer and the second free layer, as well as the ability to tune the first and second SHE layers. Moreover, the SOT differential reader improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
    Type: Application
    Filed: August 5, 2021
    Publication date: January 13, 2022
    Applicant: Western Digital Technologies, Inc.
    Inventors: Cherngye HWANG, Xiaoyong LIU, Quang LE, Kuok San HO, Hisashi TAKANO, Brian R. YORK
  • Patent number: 11222656
    Abstract: The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device that comprises a first shield, a first spin hall layer, a first free layer, a gap layer, a second spin hall layer, a second free layer, and a second shield. The gap layer functions as an electrode and is disposed between the first spin hall layer and the second spin hall layer. Electrical lead connections are located about the first spin hall layer, the second spin hall layer, the gap layer, the first shield, and/or the second shield. The electrical lead connections facilitate the flow of current and/or voltage from a negative lead to a positive lead. The positioning of the electrical lead connections and the positioning of the SOT differential layers improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
    Type: Grant
    Filed: September 23, 2020
    Date of Patent: January 11, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Xiaoyong Liu, Zhigang Bai, Zhanjie Li, Kuok San Ho, Hisashi Takano
  • Publication number: 20220005498
    Abstract: The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device that comprises a first shield, a first spin hall effect layer, a first free layer, a gap layer, a second spin hall effect layer, a second free layer, and a second shield. The gap layer is disposed between the first spin hall effect layer and the second spin hall effect layer. Electrical lead connections are located about the first spin hall effect layer, the second spin hall effect layer, the gap layer, the first shield, and/or the second shield. The electrical lead connections facilitate the flow of current and/or voltage from a negative lead to a positive lead. The positioning of the electrical lead connections and the positioning of the SOT differential layers improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
    Type: Application
    Filed: August 5, 2021
    Publication date: January 6, 2022
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Xiaoyong LIU, Zhigang BAI, Zhanjie LI, Kuok San HO, Hisashi TAKANO
  • Patent number: 11100946
    Abstract: The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device that comprises a first shield, a first spin hall effect layer, a first free layer, a gap layer, a second spin hall effect layer, a second free layer, and a second shield. The gap layer is disposed between the first spin hall effect layer and the second spin hall effect layer. Electrical lead connections are located about the first spin hall effect layer, the second spin hall effect layer, the gap layer, the first shield, and/or the second shield. The electrical lead connections facilitate the flow of current and/or voltage from a negative lead to a positive lead. The positioning of the electrical lead connections and the positioning of the SOT differential layers improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
    Type: Grant
    Filed: July 1, 2020
    Date of Patent: August 24, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Xiaoyong Liu, Zhigang Bai, Zhanjie Li, Kuok San Ho, Hisashi Takano
  • Patent number: 11094338
    Abstract: The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device comprising a first seed layer, a first spin hall effect (SHE) layer, a first interlayer, a first free layer, a gap layer, a second seed layer, a second SHE layer, a second free layer, and a second interlayer. The gap layer is disposed between the first SHE layer and the second SHE layer. The materials and dimensions used for the first and second seed layers, the first and second interlayers, and the first and second SHE layers affect the resulting spin hall voltage converted from spin current injected from the first free layer and the second free layer, as well as the ability to tune the first and second SHE layers. Moreover, the SOT differential reader improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
    Type: Grant
    Filed: September 23, 2020
    Date of Patent: August 17, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: Cherngye Hwang, Xiaoyong Liu, Quang Le, Kuok San Ho, Hisashi Takano, Brian R. York
  • Patent number: 8144415
    Abstract: To effectively suppress a signal in a low frequency region in which the medium noise and the signal distortion are concentrated, and in order to effectively utilize a detected component of the reproduced signal in the low frequency region, a target of partial response equalization to the perpendicularly recorded/reproduced signal is set so that the low-frequency component around the direct current is suppressed to a regulated quantity for both the effective suppression and the effective utilization. Accordingly, a maximum-likelihood decoding process is carried out through the target of partial response equalization. Reliability of data detection is made higher and a signal-to-noise ratio is improved, so that the noise from the recording medium can be reduced more and it is possible to provide a high-density magnetic recording/reproducing apparatus.
    Type: Grant
    Filed: September 14, 2010
    Date of Patent: March 27, 2012
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Hideki Sawaguchi, Yasutaka Nishida, Hisashi Takano, Hiroyuki Tsuchinaga
  • Publication number: 20110013306
    Abstract: To effectively suppress a signal in a low frequency region in which the medium noise and the signal distortion are concentrated, and in order to effectively utilize a detected component of the reproduced signal in the low frequency region, a target of partial response equalization to the perpendicularly recorded/reproduced signal is set so that the low-frequency component around the direct current is suppressed to a regulated quantity for both the effective suppression and the effective utilization. Accordingly, a maximum-likelihood decoding process is carried out through the target of partial response equalization. Reliability of data detection is made higher and a signal-to-noise ratio is improved, so that the noise from the recording medium can be reduced more and it is possible to provide a high-density magnetic recording/reproducing apparatus.
    Type: Application
    Filed: September 14, 2010
    Publication date: January 20, 2011
    Inventors: Hideki Sawaguchi, Yasutaka Nishida, Hisashi Takano, Hiroyuki Tsuchinaga
  • Patent number: 7839590
    Abstract: In a method of servo writing of a magnetic recording system and the magnetic recording system, the signal is recorded in a dummy area with a higher recording density than the burst signal. Also, the maximum bit length of the burst area is shortened as compared with the maximum bit length of the data area. A servo control method for perpendicular recording similar to that for longitudinal recording can be used to reduce the development cost. The anti-signal decay performance is also improved. Further, since the variations of the burst signal along the track width is suppressed, the positioning accuracy is improved. These effects combine to produce a reliable magnetic recording system of large capacity.
    Type: Grant
    Filed: September 9, 2008
    Date of Patent: November 23, 2010
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Yasutaka Nishida, Takehiko Hamaguchi, Hideki Sawaguchi, Hisashi Takano