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: 8089831
    Abstract: A plasmon generator has an outer surface including a surface plasmon exciting surface, and has a near-field light generating part located in a medium facing surface. The surface plasmon exciting surface is a flat surface that faces an evanescent light generating surface of a waveguide with a predetermined distance therebetween. The surface plasmon exciting surface includes a width changing portion. The width of the width changing portion in a direction parallel to the medium facing surface and the evanescent light generating surface decreases with decreasing distance to the medium facing surface. A magnetic pole is located at such a position that the plasmon generator is interposed between the magnetic pole and the waveguide. The outer surface of the plasmon generator includes a pole contact surface that is in contact with the magnetic pole.
    Type: Grant
    Filed: February 22, 2010
    Date of Patent: January 3, 2012
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Eiji Komura, Koji Shimazawa, Kosuke Tanaka, Daisuke Miyauchi
  • Patent number: 8085512
    Abstract: A magnetic field detecting element comprises: a stack which includes first, second and third magnetic layers whose magnetization directions depend upon an external magnetic field, the second magnetic layer being positioned between the first magnetic layer and the third magnetic layer, a first non-magnetic intermediate layer sandwiched between the first magnetic layer and the second magnetic layer, and a second non-magnetic intermediate layer sandwiched between the second magnetic layer and the third magnetic layer, wherein the stack is adapted such that sense current flows in a direction that is perpendicular to a film surface thereof; and a bias magnetic layer which is provided on a side of the stack, the side being opposite to an air bearing surface of the stack.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: December 27, 2011
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Shinji Hara, Koji Shimazawa, Tsutomu Chou
  • Publication number: 20110310713
    Abstract: A magnetic head includes a magnetic head slider; and a laser diode that is positioned on a surface of a side opposite to a substrate of the magnetic head slider and that generates laser light; the magnetic head slider including: a core through which the laser light emitted from the laser diode propagates as propagating light; a cladding that covers the core and that has a refractive index that is smaller than that of the core; a near field light generating means that generates near field light from the propagating light on an air bearing surface; and a main pole for recording that is disposed adjacent to the near field light generating means and of which an edge part is positioned on the air bearing surface.
    Type: Application
    Filed: June 22, 2010
    Publication date: December 22, 2011
    Applicant: TDK CORPORATION
    Inventors: Eiji KOMURA, Tsutomu CHOU, Koji SHIMAZAWA
  • Patent number: 8077556
    Abstract: A thermally assisted magnetic head has a medium-facing surface facing a magnetic recording medium; a near-field light generator disposed on a light exit face in the medium-facing surface; a magnetic recording element located adjacent to the near-field light generator; and a light emitting element disposed so that emitted light thereof reaches the near-field light generator; the near-field light generator is comprised of a cusp portion and a base portion; when ?in represents a wavelength of the emitted light from the light emitting element immediately before the emitted light reaches the near-field light generator, an intensity of near-field light generated when the material forming the cusp portion is irradiated with the light of the wavelength ?in is stronger than an intensity of near-field light generated when the material forming the base portion is irradiated with the light of the wavelength ?in.
    Type: Grant
    Filed: February 20, 2008
    Date of Patent: December 13, 2011
    Assignee: TDK Corporation
    Inventors: Eiji Komura, Koji Shimazawa, Kosuke Tanaka
  • Patent number: 8076246
    Abstract: A method comprises a first multilayer body forming step of forming a first multilayer body on a first cladding layer, the first multilayer body including a core layer and a first polishing stop layer in order from the first cladding layer side; a first multilayer body patterning step of pattering the first multilayer body, so as to expose the first cladding layer about the patterned first multilayer body; a second multilayer body forming step of forming a second multilayer body on the exposed first cladding layer and patterned first multilayer body, the second multilayer body including a second cladding layer and a second polishing stop layer in order from the first cladding layer side; and a removing step of polishing away a part of the second multilayer body formed on the first multilayer body.
    Type: Grant
    Filed: January 26, 2009
    Date of Patent: December 13, 2011
    Assignee: TDK Corporation
    Inventors: Kosuke Tanaka, Koji Shimazawa
  • Patent number: 8072227
    Abstract: Provided is a material for tactile sensor, which is easy to be formed, and in which the shape, size and orientation of coils dispersed in the medium are sufficiently controlled. The tactile-sensitive material includes a medium and a plurality of micro coils dispersed in the medium and constituting a LCR resonance circuit, and wherein each of the plurality of micro coils includes at least one spiral coil portion, and coil axes of the plurality of micro coils are aligned along at least one direction or directed in at least one plane. When a tactile stress is applied to the tactile-sensitive material, the C component is varied significantly, which contributes to the improvement in sensitivity of the tactile sensor. Further, by providing a core at the coil center, the sensitivity is more improved.
    Type: Grant
    Filed: November 17, 2010
    Date of Patent: December 6, 2011
    Assignee: TDK Corporation
    Inventor: Koji Shimazawa
  • Patent number: 8065786
    Abstract: Provided is a manufacturing method of heat-assisted magnetic recording head, in which a light source unit can be easily joined to a slider with sufficiently high accuracy, under avoiding the excessive mechanical stress. The manufacturing method comprises the steps of: moving relatively the light source unit and the slider, while applying a sufficient voltage between an upper electrode of the light source and an electrode layer provided in the slider; and setting the light source unit and the slider in desired positions in a direction perpendicular to the element-integration surface of the slider substrate. The desired positions are positions where the light source just emits due to a surface contact between: the protruded portion of the lower surface of the light source; and the upper surface of the electrode layer, which is a portion of the wall surface of a step formed on the head part.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: November 29, 2011
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Yasuhiro Ito, Eiji Komura, Seiichi Takayama, Kosuke Tanaka
  • Patent number: 8049997
    Abstract: A first shield portion located below an MR stack includes a first main shield layer, a first antiferromagnetic layer, and a first magnetization controlling layer including a first ferromagnetic layer exchange-coupled to the first antiferromagnetic layer. A second shield portion located on the MR stack includes a second main shield layer, a second antiferromagnetic layer, and a second magnetization controlling layer including a second ferromagnetic layer exchange-coupled to the second antiferromagnetic layer. The MR stack includes two free layers magnetically coupled to the two magnetization controlling layers. Only one of the two magnetization controlling layers includes a third ferromagnetic layer that is antiferromagnetically exchange-coupled to the first or second ferromagnetic layer through a nonmagnetic middle layer. The first shield portion includes an underlayer disposed on the first main shield layer, and the first antiferromagnetic layer is disposed on the underlayer.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: November 1, 2011
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Yoshihiro Tsuchiya, Tsutomu Chou, Shinji Hara, Takahiko Machita, Koji Shimazawa
  • Patent number: 8045422
    Abstract: Provided is a near-field light generating element in which as much amount as possible of waveguide light can be coupled with a plasmon antenna. The element comprises a light waveguide and a plasmon antenna comprising a surface or edge for propagating surface plasmon excited by waveguide light, extending to a near-field light generating end. A groove is formed in a waveguide side surface. And at least a portion of the surface or edge is embedded in the groove or located directly above the groove, being opposed to a wall or bottom surface of the groove with a predetermined distance, so as for waveguide light to be coupled with the plasmon antenna in surface plasmon mode. This configuration enables the surface or edge to be located at the position in which the surface or edge can be coupled with more amount of light, thereby to improve the light use efficiency.
    Type: Grant
    Filed: January 7, 2009
    Date of Patent: October 25, 2011
    Assignee: TDK Corporation
    Inventors: Eiji Komura, Koji Shimazawa
  • Publication number: 20110242697
    Abstract: Provided is a method for manufacturing a thermally-assisted magnetic recording head with “composite slider structure”. In the method, the waveguide is irradiated with a first light from opposed-to-medium surface side, and the passing first light is detected on back surface side to obtain an image of the light-receiving end surface, and a light-receiving center position is determined from the image. Further, the light source is irradiated with a second light from opposite side to joining surface, and the passing second light is detected on the joining surface side to obtain an image of the light-emitting end surface, and a light-emitting center position is determined from the image. Then, the slider and the light source unit are moved based on the determined positions of the light-receiving and light-emitting centers, aligned and bonded. As a result, alignment can be performed with high accuracy in a short process time under simplified process.
    Type: Application
    Filed: March 31, 2010
    Publication date: October 6, 2011
    Applicant: TDK CORPORATION
    Inventors: Nobuyuki MORI, Seiichi Takayama, Yoshihiro Tsuchiya, Yasuhiro Ito, Koji Shimazawa
  • Patent number: 8031444
    Abstract: The semiconductor oxide layer that forms a part of the spacer layer in the inventive giant magnetoresistive device (CPP-GMR device) is composed of zinc oxide of wurtzite structure that is doped with a dopant given by at least one metal element selected from the group consisting of Zn, Ge, V, and Cr in a content of 0.05 to 0.90 at %: there is the advantage obtained that ever higher MR ratios are achievable while holding back an increase in the area resistivity AR.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: October 4, 2011
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Tomohito Mizuno, Koji Shimazawa, Yoshihiro Tsuchiya, Shinji Hara, Hironobu Matsuzawa
  • Publication number: 20110235478
    Abstract: A waveguide has a core through which laser light can propagate in a TM mode, that has a rectangular cross section perpendicular to a propagative direction of the laser light, and through which the laser light can propagate in a fundamental mode in which only one portion exists on the cross section of the core where a light intensity of the laser light becomes maximal, and a higher order mode in which two or more portions exist where the light intensity becomes maximal, a clad surrounding the core, and a light absorbing element in the clad, and wherein a distance between the light absorbing element and the core is shorter than a penetration length of evanescent light in the higher order mode, but is longer than a penetration length of evanescent light in the fundamental mode.
    Type: Application
    Filed: March 23, 2010
    Publication date: September 29, 2011
    Applicant: TDK Corporation
    Inventors: Eiji KOMURA, Shinji Hara, Seiichi Takayama, Koji Shimazawa
  • Publication number: 20110228653
    Abstract: Provided is a light source unit that is to be joined to a slider to form a thermally-assisted magnetic recording head. The light source unit comprises: a unit substrate having a source-installation surface; a light source provided in the source-installation surface and emitting thermal-assist light; and a photodetector bonded to a rear joining surface of the unit substrate in such a manner that a rear light-emission center of the light source is covered with a light-receiving surface of the photodetector. The photodetector can be sufficiently close to the light source; thus, constant feedback adjustment with high efficiency for the light output of the light source can be performed. This adjustment enables light output from the light source to be controlled in response to changes in light output due to surroundings and to changes with time to stabilize the intensity of light with which a magnetic recording medium is irradiated.
    Type: Application
    Filed: March 22, 2010
    Publication date: September 22, 2011
    Applicants: TDK CORPORATION, HEADWAY TECHNOLOGIES, INC.
    Inventors: Koji SHIMAZAWA, Yoshihiro TSUCHIYA, Seiichi TAKAYAMA, Nobuyuki MORI, Yasuhiro ITO, Kosuke TANAKA, Osamu SHINDO, Ryuji FUJII, Takashi HONDA, Yoshitaka SASAKI
  • Publication number: 20110228420
    Abstract: A plasmon generator has an outer surface including a plasmon exciting part, and has a near-field light generating part located in a medium facing surface. The plasmon exciting part faces an evanescent light generating surface of a waveguide's core with a predetermined distance therebetween. The outer surface of the plasmon generator further includes first and second inclined surfaces that are each connected to the plasmon exciting part. The first and second inclined surfaces increase in distance from each other with increasing distance from the plasmon exciting part. The plasmon generator includes a shape changing portion where the angle of inclination of each of the first and second inclined surfaces with respect to the evanescent light generating surface increases continuously with decreasing distance to the medium facing surface.
    Type: Application
    Filed: March 22, 2010
    Publication date: September 22, 2011
    Applicant: TDK CORPORATION
    Inventors: Shinji Hara, Tsutomu Chou, Kosuke Tanaka, Eiji Komura, Koji Shimazawa, Daisuke Miyauchi, Susumu Aoki, Takeshi Tsutsumi
  • Publication number: 20110228649
    Abstract: A method for manufacturing a thermally-assisted magnetic recording head is provided, in which a light source unit including a light source and a slider including an optical system are bonded. A unit substrate is made of a material transmitting light having a predetermined wavelength, and an adhesion material layer is formed on the light source unit and/or the slider. The manufacturing method includes: aligning the light source unit and the slider in such a way that a light from the light source can enter the optical system and the adhesion material layer is sandwiched therebetween; irradiating the adhesion material layer with a light including the predetermined wavelength through the unit substrate; and bonding them. The adhesion material layer melted by the light including the predetermined wavelength and transmitted through the unit substrate can ensure high alignment accuracy as well as higher bonding strength and less change with time.
    Type: Application
    Filed: March 18, 2010
    Publication date: September 22, 2011
    Applicants: TDK CORPORATION, HEADWAY TECHNOLOGIES, INC.
    Inventors: Koji SHIMAZAWA, Yoshihiro TSUCHIYA, Seiichi TAKAYAMA, Nobuyuki MORI, Yasuhiro ITO, Kosuke TANAKA, Osamu SHINDO, Ryuji FUJII, Takashi HONDA, Yoshitaka SASAKI
  • Publication number: 20110228650
    Abstract: A method for manufacturing a thermally-assisted magnetic recording head is provided, in which a light source unit including a light source and a slider including an optical system are bonded. A unit substrate is made of a material transmitting light having a predetermined wavelength, and a unit adhesion material layer that contains Sn, Sn alloy, Pb alloy or Bi alloy is formed on the light source unit and/or the slider. The manufacturing method includes: aligning the light source unit and the slider in such a way that a light from the light source can enter the optical system and the unit adhesion material layer is sandwiched therebetween; and causing a light including the predetermined wavelength to enter the unit substrate to melt the unit adhesion material layer. The unit adhesion material layer melted by the light including the predetermined wavelength can ensure high alignment accuracy as well as higher bonding strength and less change with time.
    Type: Application
    Filed: October 6, 2010
    Publication date: September 22, 2011
    Applicants: TDK Corporation, Headway Technologies, Inc.
    Inventors: Koji SHIMAZAWA, Yoshihiro TSUCHIYA, Seiichi TAKAYAMA, Nobuyuki MORI, Yasuhiro ITO, Kosuke TANAKA, Osamu SHINDO, Ryuji FUJII, Takashi HONDA, Yoshitaka SASAKI
  • Patent number: 8023226
    Abstract: A thermally assisted magnetic head comprises a slider having a medium-opposing surface and a light source unit secured to a surface of the slider on the side of the slider opposite from the medium-opposing surface. The slider has a slider substrate and a magnetic head part provided on a side face of the medium-opposing surface in the slider substrate. The magnetic head part includes a magnetic recording device for generating a magnetic field and a waveguide for receiving light from an end face opposite from the medium-opposing surface and guiding the light to the medium-opposing surface side. The light source unit has a light source supporting substrate, a light source secured to the light source supporting substrate and adapted to supply light to the end face of the waveguide, and a temperature sensor for measuring the temperature of the light source.
    Type: Grant
    Filed: July 30, 2008
    Date of Patent: September 20, 2011
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Kosuke Tanaka
  • Patent number: 8023230
    Abstract: A magnetoresistive element includes a pair of shield portions, and an MR stack and a bias magnetic field applying layer that are disposed between the pair of shield portions. The shield portions respectively include single magnetic domain portions. The MR stack includes a pair of ferromagnetic layers magnetically coupled to the pair of single magnetic domain portions, and a spacer layer disposed between the pair of ferromagnetic layers. The MR stack has a front end face, a rear end face and two side surfaces. The magnetoresistive element further includes two flux guide layers disposed between the pair of single magnetic domain portions and respectively adjacent to the two side surfaces of the MR stack. Each of the two flux guide layers has a front end face and a rear end face. The bias magnetic field applying layer has a front end face that faces the rear end face of the MR stack and the respective rear end faces of the two flux guide layers.
    Type: Grant
    Filed: October 27, 2008
    Date of Patent: September 20, 2011
    Assignee: TDK Corporation
    Inventors: Takahiko Machita, Daisuke Miyauchi, Yoshihiro Tsuchiya, Tsutomu Chou, Shinji Hara, Koji Shimazawa
  • Patent number: 8023225
    Abstract: While an emitting position of light from an optical waveguide and a magnetic pole end part are made closer to each other, high-density writing onto a magnetic recording medium is realized. A thermally assisted magnetic head comprises a main magnetic pole layer having a magnetic pole end part exposed at a medium-opposing surface opposing a magnetic disk, and an optical waveguide for deflecting laser light incident thereon into a laminating direction. The main magnetic pole layer is positioned on a side where the light is deflected by the optical waveguide. The magnetic pole end part projects to the side where the light is deflected by the optical waveguide. The optical waveguide projects more than the magnetic pole end part on the medium-opposing surface side.
    Type: Grant
    Filed: July 18, 2008
    Date of Patent: September 20, 2011
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Hiraku Hirabayashi, Kosuke Tanaka, Eiji Komura
  • Publication number: 20110222184
    Abstract: An optical waveguide, on account of its ability to apply phase resonance of a wavelength and of a first and second triangular plate-like spot size converter members formed of the same material as a core material and being arranged and formed in a substantially symmetrical structure, can promote shortening of the waveguide length and contrive to reduce the size of the optical waveguide itself. Further, an optical waveguide having excellent spot size conversion efficiency can be obtained even in a reduced size.
    Type: Application
    Filed: March 9, 2010
    Publication date: September 15, 2011
    Applicant: TDK CORPORATION
    Inventors: Eiji KOMURA, Tsutomu CHOU, Koji SHIMAZAWA, Seiichi TAKAYAMA