Patents by Inventor Kenji Shimizu

Kenji Shimizu 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: 20040137277
    Abstract: A perpendicular magnetic recording medium includes a magnetic recording layer stacked on a substrate and having a first perpendicular magnetic recording layer containing cobalt, and a second perpendicular magnetic recording layer mainly containing a crystalline alloy which contains a rare earth element and a transition metal.
    Type: Application
    Filed: July 25, 2003
    Publication date: July 15, 2004
    Applicants: KABUSHIKI KAISHA TOSHIBA, SHOWA DENKO K.K.
    Inventors: Takeshi Iwasaki, Takashi Hikosaka, Soichi Oikawa, Futoshi Nakamura, Hiroshi Sakai, Kenji Shimizu, Akira Sakawaki
  • Publication number: 20040106010
    Abstract: Disclosed is a perpendicular magnetic recording medium comprising a perpendicular magnetic layer formed at 280 to 450° C. by using a magnetic layer-forming material containing at least one additive component selected from the group consisting of cobalt, platinum, chromium, molybdenum and tungsten, the magnetic perpendicular layer being constructed to include a plurality of magnetic crystal grains separated from each other by crystal grain boundaries and providing the perpendicular magnetic layer in which the additive component is segregated in the crystal grain boundaries.
    Type: Application
    Filed: November 6, 2003
    Publication date: June 3, 2004
    Applicants: KABUSHIKI KAISHA TOSHIBA, SHOWA DENKO K,K,
    Inventors: Takeshi Iwasaki, Takashi Hikosaka, Soichi Oikawa, Futoshi Nakamura, Hiroshi Sakai, Kenji Shimizu, Akira Sakawaki
  • Patent number: 6723458
    Abstract: A magnetic recording medium that is capable of recording and reading back information at a higher density by improving the read/write characteristics and thermal stability, a method of manufacture therefor, and a magnetic read/write apparatus are provided. This magnetic recording medium, comprises an orientation control film that controls the orientation of a film provided directly thereabove, a perpendicular magnetic film, of which the axis of easy magnetization is generally oriented perpendicular to a non-magnetic substrate, and a protective film, that are provided on the non-magnetic substrate, wherein the perpendicular magnetic film is made of a material which contains Co, Cr, Pt and Cu, the Cr content being 16 at % to 24 at % and the Cu content being 0.
    Type: Grant
    Filed: August 15, 2002
    Date of Patent: April 20, 2004
    Assignees: Showa Denko K.K., Toshiba Corporation
    Inventors: Kenji Shimizu, Akira Sakawaki, Hui Yang, Hiro Mochizuki, Hiroshi Sakai, Takashi Hikosaka, Futoshi Nakamura
  • Publication number: 20040057157
    Abstract: A magnetic recording medium includes a nonmagnetic substrate on which is provided at least a softly magnetic under-film, an orientation control film that controls an orientation of a film directly above, a perpendicular magnetic recording film having an axis of easy magnetization oriented to be mainly perpendicular to the substrate and a protective film, wherein the orientation control film has a material composition forming a C11b structure. The magnetic recording medium is manufactured by a method including carrying out, in order, at least a step of forming a softly magnetic under-film on a nonmagnetic substrate, a step of forming an orientation control film that controls an orientation of a film directly above, a step of forming a perpendicular magnetic recording film having an axis of easy magnetization oriented to be mainly perpendicular to the substrate, and a step of forming a protective film.
    Type: Application
    Filed: July 14, 2003
    Publication date: March 25, 2004
    Applicant: SHOWA DENKO K.K.
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiroshi Sakai, Takashi Hikosaka, Takeshi Iwasaki
  • Patent number: 6699600
    Abstract: A magnetic recording medium comprising: on a non-magnetic substrate, at least a soft magnetic undercoat film comprising a soft magnetic material; an orientation control film for controlling an orientation of a film directly above; a perpendicular magnetic film in which an axis of easy magnetization is oriented mainly perpendicularly with respect to the substrate; and a protection film, wherein the perpendicular magnetic film has a structure in which a large number of magnetic grains are separated by a grain boundary layer, and an average separating distance between the magnetic grains along a straight line which connects centers of gravity of mutually neighboring magnetic grains is 1 nm or greater.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: March 2, 2004
    Assignees: Showa Denko K.K., Kabushiki Kaisha Toshiba
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiroshi Sakai, Takashi Hikosaka, Soichi Oikawa
  • Publication number: 20040033390
    Abstract: A medium having at least a nonmagnetic substrate, soft magnetic backing layer, soft magnetic underlayer, and perpendicular magnetic recording layer, and An oxidized layer of the soft magnetic backing layer is also formed on the soft magnetic backing layer, and the soft magnetic underlayer has a three-layered structure including a first soft magnetic layer, interlayer, and second soft magnetic layer, a crystalline orientation control layer, e.g., an Ni orientation control layer is formed between the soft magnetic underlayer and the perpendicular magnetic recording layer.
    Type: Application
    Filed: August 14, 2003
    Publication date: February 19, 2004
    Applicants: KABUSHIKI KAISHA TOSHIBA, SHOWA DENKO K.K.
    Inventors: Soichi Oikawa, Takashi Hikosaka, Hiroshi Sakai, Akira Sakawaki, Kenji Shimizu
  • Publication number: 20040023073
    Abstract: A magnetic recording medium includes a nonmagnetic substrate on which is provided at least a softly magnetic under-film, an orientation control film that controls an orientation of a film directly above, a perpendicular magnetic recording film having an axis of easy magnetization oriented to be mainly perpendicular to the substrate and a protective film, wherein the orientation control film is alloy containing at least Cr and C. The magnetic recording medium is manufactured by a method including carrying out, in order, at least a step of forming a softly magnetic under-film on a nonmagnetic substrate, a step of forming an orientation control film that controls an orientation of a film directly above, a step of forming a perpendicular magnetic recording film having an axis of easy magnetization oriented to be mainly perpendicular to the substrate, and a step of forming a protective film.
    Type: Application
    Filed: July 31, 2003
    Publication date: February 5, 2004
    Applicants: SHOWA DENKO K.K., KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiroshi Sakai, Takashi Hikosaka, Futoshi Nakamura
  • Publication number: 20040023074
    Abstract: The magnetic recording medium comprises a soft magnetic undercoat film, an orientation control film that controls the orientation of a film provided directly above, a perpendicular magnetic film of which axis of easy magnetization is generally oriented perpendicular to a non-magnetic substrate, and a protective film, that are provided on the non-magnetic substrate, wherein the orientation control film is made of a Co alloy which contains one or more elements selected from Ti, V, Sr, Y, Nb, Mo, Hf, Ta, Ni and W.
    Type: Application
    Filed: July 31, 2003
    Publication date: February 5, 2004
    Applicant: SHOWA DENKO K.K. AND KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiroshi Sakai, Takashi Hikosaka, Soichi Oikawa
  • Patent number: 6682826
    Abstract: The present invention provides a magnetic recording medium having excellent magnetic read/write characteristics and thermal stability, a method of manufacturing therefor, and a magnetic read/write apparatus. The magnetic recording medium comprises a soft magnetic undercoat film, an orientation control film, a perpendicular magnetization film, and a protective film, that are formed on a non-magnetic substrate, wherein the orientation control film has an hcp structure and, at the same time, &Dgr;&thgr;50 of the (0002) orientation plane is set within a range from 3 to 10 degrees and a difference (&Dgr;&thgr;50 (mag)−&Dgr;&thgr;50 (ori)) between &Dgr;&thgr;50 (ori) of the orientation control film and &Dgr;&thgr;50 (mag) of the perpendicular magnetization film is set within a range from 1 to 8 degrees.
    Type: Grant
    Filed: July 25, 2002
    Date of Patent: January 27, 2004
    Assignees: Showa Denko K.K., Toshiba Corporation
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiro Mochizuki, Hiroshi Sakai, Soichi Oikawa, Takashi Hikosaka
  • Publication number: 20040013909
    Abstract: A magnetic recording medium comprising at least a soft magnetic layer, an orientation control film that controls the orientation of a film provided directly thereabove, an intermediate film, a perpendicular magnetic recording film of which the axis of easy magnetization is generally oriented perpendicular to a non-magnetic substrate, and a protective film, that are provided on said substrate, wherein the intermediate film has saturation magnetization Ms of at least 20 (emu/cc) and equal to or less than 200 (emu/cc), a method of manufacture thereof, and a magnetic read/write apparatus.
    Type: Application
    Filed: July 14, 2003
    Publication date: January 22, 2004
    Applicants: SHOWA DENKO K.K., KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiroshi Sakai, Takashi Hikosaka, Soichi Oikawa
  • Patent number: 6677061
    Abstract: A magnetic recording medium exhibiting excellent recording and reproduction characteristics is disclosed. A magnetic recording medium includes a non-magnetic substrate 1; a soft magnetic undercoat film 2; an orientation-regulating film 3; a perpendicular magnetic film 4; and a protective film 5, the films being formed on the substrate 1. The soft magnetic undercoat film 2 contains a material represented by the following composition: aFe-bCo-cM-dX1-fN where M is one or more elements selected from Ti, Zr, Nb, Hf, Ta, V, and Mo; X1 is one or more elements selected from Cr, Ga, Al, Si, and Ni; and a, b, c, d, and f represent atomic percentages and satisfy the following relations: 60≦a+b≦90, 30≦a≦90, 5≦c≦20, 0.1≦d≦7, and 3≦f≦30.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: January 13, 2004
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiroshi Sakai
  • Publication number: 20040001975
    Abstract: A double layered perpendicular recording media having, between a soft magnetic layer and perpendicular magnetic recording layer, an alignment control layer containing an amorphous portion, a crystal size control layer, and an underlayer having one of a hexagonal closest packed structure and a face-centered cubic structure.
    Type: Application
    Filed: June 5, 2003
    Publication date: January 1, 2004
    Applicants: KABUSHIKI KAISHA TOSHIBA, SHOWA DENKO K.K.
    Inventors: Takashi Hikosaka, Takeshi Iwasaki, Futoshi Nakamura, Soichi Oikawa, Hiroshi Sakai, Kenji Shimizu, Akira Sakawaki
  • Patent number: 6663988
    Abstract: An object of the present invention is to provide a magnetic recording medium exhibiting excellent noise characteristics. On a substrate, an undercoat film is formed, and a perpendicular magnetic film, in which most of the easy-magnetization axes are oriented vertically with respect to the substrate, is formed on the undercoat film. A rocking curve 21 obtained through &thgr;-2 &thgr; scanning employing X-ray diffraction in relation to the magnetic film has a plurality of local maximum points 22 and 23.
    Type: Grant
    Filed: April 27, 2001
    Date of Patent: December 16, 2003
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Kenji Shimizu, Hiroshi Sakai
  • Publication number: 20030197370
    Abstract: An expansion section for expanding the distance between longitudinal side surfaces of an opening of a tube when being inserted a predetermined depth into the opening is formed an expansion wedge body, and guide protuberances are protrusively formed on the respective longitudinal sides of the expansion section. The guide protuberances are inserted into the spaces provided on the respective sides of the opening of the tube, thereby guiding the expansion section into the opening.
    Type: Application
    Filed: May 7, 2003
    Publication date: October 23, 2003
    Applicant: CALSONIC KANSEI CORPORATION
    Inventors: Koji Tatsuta, Kenji Shimizu, Shizuo Matsumoto
  • Patent number: 6627301
    Abstract: The present invention provides a magnetic recording medium exhibiting excellent noise characteristics and thermal stability. On a substrate, a first undercoat film, a first perpendicular magnetic film, a second undercoat film, a non-magnetic intermediate film, a second perpendicular magnetic film, and a protective film are successively formed, and the magnetic anisotropy energy of the first perpendicular magnetic film is higher than that of the second perpendicular magnetic film.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: September 30, 2003
    Assignee: Showa Denko Kabushiki Kaisha
    Inventors: Kenji Shimizu, Akira Itoh, Hiroshi Sakai
  • Publication number: 20030170500
    Abstract: The present invention provides a magnetic recording medium having excellent magnetic read/write characteristics and thermal stability, a method of manufacturing therefor, and a magnetic read/write apparatus. The magnetic recording medium comprising a soft magnetic undercoat film 2, an orientation control film 3, a perpendicular magnetization film 4, and a protective film 5, that are formed on a non-magnetic substrate 1, wherein the orientation control film 3 has an hcp structure and, at the same time, &Dgr;&thgr;50 of the (0002) orientation plane is set within a range from 3 to 10 degrees and a difference (&Dgr;&thgr;50 (mag)−&Dgr;&thgr;50 (ori)) between &Dgr;&thgr;50 (ori) of the orientation control film 3 and &Dgr;&thgr;50 (mag) of the perpendicular magnetization film 4 is set within a range from 1 to 8 degrees.
    Type: Application
    Filed: July 25, 2002
    Publication date: September 11, 2003
    Applicant: SHOWA DENKO K.K.
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiro Mochizuki, Hiroshi Sakai, Soichi Oikawa, Takashi Hikosaka
  • Publication number: 20030104250
    Abstract: A magnetic recording medium that is capable of recording and reading back information at a higher density by improving the read/write characteristics and thermal stability, a method of manufacture therefor, and a magnetic read/write apparatus are provided. This magnetic recording medium, comprises an orientation control film that controls the orientation of a film provided directly thereabove, a perpendicular magnetic film, of which the axis of easy magnetization is generally oriented perpendicular to a non-magnetic substrate, and a protective film, that are provided on the non-magnetic substrate, wherein the perpendicular magnetic film is made of a material which contains Co, Cr, Pt and Cu, the Cr content being 16 at % to 24 at % and the Cu content being 0.
    Type: Application
    Filed: August 15, 2002
    Publication date: June 5, 2003
    Applicant: SHOWA DENKO K.K. and TOSHIBA CORPORATION
    Inventors: Kenji Shimizu, Akira Sakawaki, Hui Yang, Hiro Mochizuki, Hiroshi Sakai, Takashi Hikosaka, Futoshi Nakamura
  • Patent number: 6572153
    Abstract: A structure for mounting a tube to a header member of heat exchanger is such that the header member has a tube hole and the tube is disposed through the tube hole so that a portion of the tube projects out of and beyond the header member. The portion of the tube which projects outwardly is expanded via the insertion of an expansion wedge to establish a tight contact between the tube and the tube hole.
    Type: Grant
    Filed: February 23, 2000
    Date of Patent: June 3, 2003
    Assignee: Calsonic Kansei Corporation
    Inventors: Koji Tatsuta, Kenji Shimizu, Shizuo Matsumoto
  • Publication number: 20030099869
    Abstract: In a magnetic recording medium, a longitudinal hard magnetic layer, interlayer, longitudinal soft magnetic layer, and magnetic recording layer are multilayered on a substrate. The interlayer is one of a magnetic layer having saturation magnetization smaller than that of the longitudinal hard magnetic layer, a nonmagnetic layer mainly containing cobalt or ruthenium or having a thickness of 0.5 nm or less, and an oxide layer of the longitudinal hard magnetic layer.
    Type: Application
    Filed: September 5, 2002
    Publication date: May 29, 2003
    Inventors: Soichi Oikawa, Takashi Hikosaka, Futoshi Nakamura, Takeshi Iwasaki, Hiroshi Sakai, Akira Sakawaki, Kenji Shimizu
  • Publication number: 20030091868
    Abstract: A magnetic recording medium exhibiting excellent recording and reproduction characteristics is disclosed. A magnetic recording medium includes a non-magnetic substrate 1; a soft magnetic undercoat film 2; an orientation-regulating film 3; a perpendicular magnetic film 4; and a protective film 5, the films being formed on the substrate 1.
    Type: Application
    Filed: May 23, 2002
    Publication date: May 15, 2003
    Applicant: SHOWA DENKO K.K.
    Inventors: Kenji Shimizu, Akira Sakawaki, Hiroshi Sakai