Patents by Inventor Koji Shimazawa

Koji Shimazawa 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).

  • Patent number: 11043240
    Abstract: A near field transducer (NFT) with an upper RhIr layer having an Ir content from 20-80 atomic % and a lower Au layer is formed between a waveguide and main pole at an air bearing surface (ABS). The RhIr layer has a rod-like front portion (peg) up to height h1, and a substantially triangular shaped back portion (body) from h1 to height h2. In some embodiments, there is a Rh underlayer with a thickness from 10 Angstroms to 200 Angstroms between the upper and lower NFT layers, and extending from the ABS to h2 so that the RhIr layer has a substantially uniform microcrystalline structure throughout to prevent thermally induced rupture defects proximate to h1. Optionally, the Rh underlayer may have a front side at h1, and may further comprise a lower Al or Zr adhesion layer. Accordingly, there is improved device reliability.
    Type: Grant
    Filed: February 25, 2020
    Date of Patent: June 22, 2021
    Assignee: Headway Technologies, Inc.
    Inventors: Koji Shimazawa, Shengyuan Wang
  • Patent number: 10872628
    Abstract: A near field transducer (NFT) is formed between a waveguide and main pole at an air bearing surface (ABS). The NFT includes a rod-like front portion (PG1) and a substantially triangular shaped back portion (PG2) with a dielectric separation layer therebetween. PG1 is formed on a first dielectric layer with thickness t1 and refractive index (RI1) while PG2 is on a second dielectric layer with thickness t2 and having refractive index (RI2) where t1>t2, and RI1>RI2 while PG1 has a tapered backside at angle 45+15 degrees to promote efficient energy transfer from PG2 to PG1 and reduce NFT heating. A dielectric layer that induces poor adhesion with PG1 may be inserted between below PG1 at the ABS to cause Au recession to occur at the PG1 leading side thereby preventing voids at the PG1 trailing side and ensuring good ADC performance.
    Type: Grant
    Filed: February 25, 2020
    Date of Patent: December 22, 2020
    Assignee: Headway Technologies, Inc.
    Inventors: Koji Shimazawa, Weihao Xu
  • Patent number: 10566013
    Abstract: A light source unit for thermally-assisted magnetic head includes a substrate member having a bonding surface, multiple layers formed on the bonding surface and comprising a base layer, a connection pad layer, an insulation layer and a bonding layer; a light source assembly attached on the bonding layer of the substrate member and having a laser diode embedded therein and connected to the connection pad layer on the bonding surface, so as to form a laser diode circuit; and a heater buried in the insulation layer and connected to the connection pad layer, so as to form a heater circuit. The light source unit can maintain stable heat power for facilitating performance of the thermally-assisted magnetic head, and further reduce the sizes of the light source unit and substrate member.
    Type: Grant
    Filed: January 17, 2019
    Date of Patent: February 18, 2020
    Assignees: SAE MAGNETICS (H.K.) LTD., HEADWAY TECHNOLOGIES, INC.
    Inventors: Takashi Honda, Ryo Hosoi, Wah Chun Chan, Makoto Kawato, Dayu Zhou, Koji Shimazawa, Kowang Liu
  • Publication number: 20190206433
    Abstract: A TAMR (thermally assisted magnetic recording) write head uses a gap-based NFT (near-field transducer) to create plasmon near field energy. In one embodiment the NFT is a double ridge aperture structure that simultaneously delivers low transition curvature and better cross-track thermal gradients than previous designs. In another embodiment a NFT comprises a top and bottom ridge not confined to an aperture structure, made of thermo-mechanically stable materials and a parabolic shaped metal layer disposed adjacent to a dielectric waveguide core to couple optical energy to surface plasmon modes.
    Type: Application
    Filed: December 29, 2017
    Publication date: July 4, 2019
    Inventors: Matteo Staffaroni, Koji Shimazawa, Tobias Maletzky, Xuhui Jin, Yoshihiro Tsuchiya, Tsutomu Chou
  • Patent number: 10332553
    Abstract: A TAMR (thermally assisted magnetic recording) write head uses a gap-based NFT (near-field transducer) to create plasmon near field energy. In one embodiment the NFT is a double ridge aperture structure that simultaneously delivers low transition curvature and better cross-track thermal gradients than previous designs. In another embodiment a NFT comprises a top and bottom ridge not confined to an aperture structure, made of thermo-mechanically stable materials and a parabolic shaped metal layer disposed adjacent to a dielectric waveguide core to couple optical energy to surface plasmon modes.
    Type: Grant
    Filed: December 29, 2017
    Date of Patent: June 25, 2019
    Assignee: Headway Technologies, Inc.
    Inventors: Matteo Staffaroni, Koji Shimazawa, Tobias Maletzky, Xuhui Jin, Yoshihiro Tsuchiya, Tsutomu Chou
  • Patent number: 10043542
    Abstract: A plasmon generator generates surface plasmon and generates near-field light from the surface plasmon at a distal end surface situated on an air bearing surface facing a magnetic recording medium. The plasmon generator has a first portion including the distal end surface, a second portion situated away from the air bearing surface, and a separating layer situated between the first portion and the second portion and separating the first portion from the second portion.
    Type: Grant
    Filed: March 25, 2016
    Date of Patent: August 7, 2018
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Tsutomu Chou, Yoshihiro Tsuchiya, Kosuke Tanaka
  • Patent number: 10020193
    Abstract: A laser annealing method that includes forming a second layer having through holes on a first layer, and radiating laser light with a wavelength of 3 ?m or greater to the first layer via the through holes.
    Type: Grant
    Filed: June 10, 2016
    Date of Patent: July 10, 2018
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Tsutomu Chou
  • Patent number: 9980395
    Abstract: A manufacturing method of laser diode unit of the present invention includes steps: placing a laser diode on top of a solder member formed on a mounting surface of a submount, applying a pressing load to the laser diode and pressing the laser diode against the solder member, next, melting the solder member by heating the solder member at a temperature higher than a melting point of the solder member while the pressing load is being applied, and thereafter, bonding the laser diode to the submount by cooling and solidifying the solder member, thereafter, removing the pressing load, and softening the solidified solder member by heating the solder member at a temperature lower than the melting point of the solder member after the pressing load has been removed, and thereafter cooling and re-solidifying the solder member.
    Type: Grant
    Filed: September 22, 2014
    Date of Patent: May 22, 2018
    Assignees: TDK Corporation, ROHM CO., LTD., SAE Magnetics (H.K.) Ltd.
    Inventors: Koji Shimazawa, Osamu Shindo, Yoshihiro Tsuchiya, Yasuhiro Ito, Kenji Sakai
  • Patent number: 9818436
    Abstract: A thermal assisted magnetic recording head that performs magnetic recording while locally heating a magnetic recording medium includes: a plasmon generator that generates a surface plasmon and that generates near-field light from the surface plasmon on a front end surface positioned on an air bearing surface opposing the magnetic recording medium; a dielectric body layer positioned around the plasmon generator; and an adhesion layer positioned between the plasmon generator and the dielectric body layer. The adhesion layer is made from at least one of IrOx, RuOx, NiOx and CoOx.
    Type: Grant
    Filed: March 30, 2016
    Date of Patent: November 14, 2017
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Shuji Okame, Yoshihiro Tsuchiya, Takafumi Kobayashi
  • Publication number: 20170287513
    Abstract: A thermal assisted magnetic recording head that performs magnetic recording while locally heating a magnetic recording medium includes: a plasmon generator that generates a surface plasmon and that generates near-field light from the surface plasmon on a front end surface positioned on an air bearing surface opposing the magnetic recording medium; a dielectric body layer positioned around the plasmon generator; and an adhesion layer positioned between the plasmon generator and the dielectric body layer. The adhesion layer is made from at least one of IrOx, RuOx, NiOx and CoOx.
    Type: Application
    Filed: March 30, 2016
    Publication date: October 5, 2017
    Inventors: Koji SHIMAZAWA, Shuji OKAME, Yoshihiro TSUCHIYA, Takafumi KOBAYASHI
  • Publication number: 20170278530
    Abstract: A plasmon generator generates surface plasmon and generates near-field light from the surface plasmon at a distal end surface situated on an air bearing surface facing a magnetic recording medium. The plasmon generator has a first portion including the distal end surface, a second portion situated away from the air bearing surface, and a separating layer situated between the first portion and the second portion and separating the first portion from the second portion.
    Type: Application
    Filed: March 25, 2016
    Publication date: September 28, 2017
    Inventors: Koji SHIMAZAWA, Tsutomu CHOU, Yoshihiro TSUCHIYA, Kosuke TANAKA
  • Patent number: 9659582
    Abstract: A method of manufacturing an electronic device includes a positioning step of positioning a first member supporting a laser diode with respect to a second member having a waveguide, a bonding step of bonding the first member and the second member together, and a checking step of checking the accuracy of positioning of the first member with respect to the second member. In the positioning step, the laser diode is energized to allow laser light to be emitted, and the laser light is allowed to be incident on the incidence end of the waveguide. In the bonding step, a bonding material is melted by irradiating the first member with heating light while the laser diode is not energized. In the checking step, the laser diode is energized again.
    Type: Grant
    Filed: January 25, 2013
    Date of Patent: May 23, 2017
    Assignees: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Seiichi Takayama, Yasuhiro Ito, Nobuyuki Mori, Koji Shimazawa, Kazuaki Takanuki, Youichi Ando
  • Patent number: 9640206
    Abstract: A thermal assisted magnetic recording head executing magnetic recording while locally heating a magnetic recording medium includes a plasmon generator generating surface plasmon and generating near-field light from the surface plasmon at an end surface situated on an air bearing surface facing the magnetic recording medium, a main pole being in contact with the plasmon generator and exposed on the air bearing surface, a metal protective layer situated on an opposite side to the plasmon generator when viewed from the main pole and positioned to overlap with a part of the main pole when viewed from one side in a down track direction, and an overcoat protective layer covering the metal protective layer. The overcoat protective layer is formed on a flat surface at least at a position where it overlaps with the main pole when viewed from one side in the down track direction, and the metal protective layer configures a part of the flat surface.
    Type: Grant
    Filed: May 27, 2016
    Date of Patent: May 2, 2017
    Assignee: TDK Corporation
    Inventors: Masahiro Saito, Koji Shimazawa, Daisuke Miyauchi, Ryo Hosoi, Makoto Isogai
  • Patent number: 9620151
    Abstract: A plasmon generator generates a surface plasmon, and generates a near-field light from the surface plasmon on a front end surface positioned on an air bearing surface opposing to a magnetic recording medium. The plasmon generator has a first surface that is adjacent to the front end surface and that faces a lower layer where the plasmon generator is deposited, and a second surface at the back side of the first surface relative to a down track direction. The first surface tilts toward a surface that is orthogonal to the down track direction, and, is parallel to across track direction, and the plasmon generator is deposited with a (111) orientation from the first surface toward the second surface.
    Type: Grant
    Filed: May 12, 2016
    Date of Patent: April 11, 2017
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Yoshihiro Tsuchiya, Shuji Okame
  • Patent number: 9489972
    Abstract: A light source unit has a substrate, a light source that is mounted to the substrate. The light source includes; a first emission part that emits a forward light, the forward light being a laser light in an oscillation state; a second emission part that is located on a side opposite to the first emission part and that emits a rearward light, the rearward light being a laser light in an oscillation state; and a light leakage part located at a position different from the first emission part and the second emission part. The light source further includes a photodetector that is provided on the substrate, wherein the photodetector has a light receiving surface for detecting a leakage light that leaks from the light leakage part.
    Type: Grant
    Filed: March 13, 2015
    Date of Patent: November 8, 2016
    Assignees: SAE MAGNETICS (H.K.) LTD., TDK CORPORATION, ROHM CO., LTD.
    Inventors: Takashi Honda, Seiichi Takayama, Ryuji Fujii, Koji Shimazawa, Tsuguki Noma, Yoshiteru Nagai
  • Publication number: 20160232928
    Abstract: A light source unit has a substrate, a light source that is mounted to the substrate. The light source includes; a first emission part that emits a forward light, the forward light being a laser light in an oscillation state; a second emission part that is located on a side opposite to the first emission part and that emits a rearward light, the rearward light being a laser light in an oscillation state; and a light leakage part located at a position different from the first emission part and the second emission part. The light source further includes a photodetector that is provided on the substrate, wherein the photodetector has a light receiving surface for detecting a leakage light that leaks from the light leakage part.
    Type: Application
    Filed: March 13, 2015
    Publication date: August 11, 2016
    Inventors: Takashi HONDA, Seiichi TAKAYAMA, Ryuji FUJII, Koji SHIMAZAWA, Tsuguki NOMA, Yoshiteru NAGAI
  • Patent number: 9305573
    Abstract: A thermally assisted magnetic recording head includes core that propagates laser light as propagation light, a near-field light generator that faces a portion of the core and extends to an air bearing surface (ABS), the near-field light generator coupled to the propagation light propagating through the core so as to generate a surface plasmon, propagating the surface plasmon to an end part facing the ABS, and generating near-field light at the end part to irradiate the near-field light to a magnetic recording medium, a main magnetic pole layer provided in the vicinity of the near-field light generator where an end part is positioned on the ABS, a laser diode that generates laser light of wavelength 890 nm to 1,000 nm and enters the laser light into the core, and a photodiode provided on a silicon substrate measures an intensity of the laser light entering from the laser diode to the core.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: April 5, 2016
    Assignee: TDK Corporation
    Inventors: Shinji Hara, Tsutomu Chou, Koji Shimazawa, Eiji Komura, Seiichi Takayama, Yasuhiro Ito
  • Publication number: 20160019922
    Abstract: While a plurality of drive currents for flying height setting with current values smaller than a tentative optimum drive current are supplied to a light source, respectively, heater power is supplied to a heater part, and touch down of a thermally-assisted magnetic recording head is detected. Tentative optimum heater power is determined based on a correlation between the heater power when the touch down is detected and each drive current for flying height setting. The tentative optimum drive current is supplied to the light source part; the tentative optimum heater power is supplied to the heater part; a reference signal is recorded in a magnetic recording medium; and flying height of the thermally-assisted magnetic recording head is set by determining whether or not the reference signal is recorded with the desired signal intensity.
    Type: Application
    Filed: July 21, 2014
    Publication date: January 21, 2016
    Inventors: Norikazu OTA, Osamu NAKADA, Mitsuo OTSUKI, Shinji HARA, Daisuke MIYAUCHI, Tetsuya ROPPONGI, Koji SHIMAZAWA
  • Patent number: 9230586
    Abstract: While a plurality of drive currents for flying height setting with current values smaller than a tentative optimum drive current are supplied to a light source, respectively, heater power is supplied to a heater part, and touch down of a thermally-assisted magnetic recording head is detected. Tentative optimum heater power is determined based on a correlation between the heater power when the touch down is detected and each drive current for flying height setting. The tentative optimum drive current is supplied to the light source part; the tentative optimum heater power is supplied to the heater part; a reference signal is recorded in a magnetic recording medium; and flying height of the thermally-assisted magnetic recording head is set by determining whether or not the reference signal is recorded with the desired signal intensity.
    Type: Grant
    Filed: July 21, 2014
    Date of Patent: January 5, 2016
    Assignee: TDK Corporation
    Inventors: Norikazu Ota, Osamu Nakada, Mitsuo Otsuki, Shinji Hara, Daisuke Miyauchi, Tetsuya Roppongi, Koji Shimazawa
  • Patent number: 9177572
    Abstract: The thermally-assisted magnetic recording method is a method to perform information recording on a magnetic recording medium by a thermally-assisted magnetic recording head having a magnetic pole and a heating element, and the method includes: performing annealing treatment of the heating element through applying first energy to the heating element and heating the heating element; and performing information recording to a predetermined recording region of the magnetic recording medium after the annealing treatment. The information recording is performed through rotating the magnetic recording medium as well as floating the thermally-assisted magnetic recording head above the magnetic recording medium, and applying second energy to the heating element to heat a predetermined recording region of the magnetic recording medium as well as applying a write magnetic field from the magnetic pole to the predetermined recording region.
    Type: Grant
    Filed: December 12, 2013
    Date of Patent: November 3, 2015
    Assignees: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Koji Shimazawa, Pak Kin Wong, Vincent Man Fat Chiah