Patents by Inventor Masatoshi Sakurai

Masatoshi Sakurai 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).

  • Magnetic recording medium and method of manufacturing the same
    Patent number: 7923136
    Abstract: According to one embodiment, a magnetic recording medium includes magnetic patterns made of a ferromagnetic recording layer containing Co, and a nonmagnetic layer which separates the magnetic patterns and has a lower Co concentration than the magnetic patterns.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: April 12, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Masatoshi Sakurai
  • METHOD OF MANUFACTURING MAGNETIC RECORDING MEDIUM
    Publication number: 20110049090
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a magnetic recording layer, an etching protection layer, and an adhesion layer on a substrate, applying a resist on the adhesion layer, transferring patterns of protrusions and recesses on the resist by imprinting to form a resist pattern, patterning the adhesion layer by using the resist pattern as a mask, patterning the etching protection layer by using the resist pattern as a mask, etching the magnetic recording layer by using patterns of the adhesion layer and the etching protection layer as masks to form patterns of protrusions and recesses of the magnetic recording layer and removing the pattern of the adhesion layer, stripping the pattern of the etching protection layer, and exposing the patterns of protrusions and recesses of the magnetic recording layer to a non-ionized reducing gas.
    Type: Application
    Filed: August 31, 2010
    Publication date: March 3, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshiyuki KAMATA, Hiromi YUASA, Shuichi MURAKAMI, Hideaki FUKUZAWA, Michiko HARA, Yoshihiko FUJI, Masatoshi SAKURAI
  • ULTRAVIOLET-CURABLE RESIN MATERIAL FOR PATTERN TRANSFER AND MAGNETIC RECORDING MEDIUM MANUFACTURING METHOD USING THE SAME
    Publication number: 20110049089
    Abstract: According to one embodiment, an ultraviolet curing curable resin material for pattern transfer is provided. The resin contains isobornyl acrylate, an acrylate having a fluorene skeleton, a polyfunctional acrylate, and a polymerization initiator.
    Type: Application
    Filed: August 31, 2010
    Publication date: March 3, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuyo MORITA, Seiji MORITA, Shinobu SUGIMURA, Masatoshi SAKURAI
  • Patterned medium with magnetic pattern depth relationship
    Patent number: 7898768
    Abstract: A patterned media has a substrate, and a magnetic recording layer on the substrate including protruded magnetic patterns and a nonmagnetic material filled in between the protruded magnetic patterns. In the patterned media, a depth Db and a depth Da, which are defined that Db is a depth from a surface of the magnetic patterns to a surface of the nonmagnetic material filled in a first central part between the magnetic patterns adjacent to each other in a cross-track direction or a down-track direction, and Da is a depth from a surface of the magnetic patterns to a surface of the nonmagnetic material filled in a second central part in a portion surrounded by the magnetic patterns, have a relationship that the depth Da is greater than the depth Db.
    Type: Grant
    Filed: March 15, 2007
    Date of Patent: March 1, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Kamata, Masatoshi Sakurai, Satoshi Shirotori, Kaori Kimura
  • Magnetic recording medium, method of fabricating the same, and magnetic recording apparatus
    Patent number: 7894155
    Abstract: According to one embodiment, there is provided a magnetic recording medium having a data region in which a plurality of recording tracks, each including magnetic dots arrayed in a down-track direction with a pitch p, are formed in a cross-track direction, and a servo region including a preamble in which a plurality of lines of magnetic dots, which are arrayed in a cross-track direction with a pitch p, are formed at equal intervals in the down-track direction.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: February 22, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Kazuto Kashiwagi, Akira Kikitsu
  • MAGNETIC DISK APPARATUS
    Publication number: 20110019306
    Abstract: According to one embodiment, there is provided a magnetic disk apparatus having a magnetic disk having magnetic dot lines each including magnetic dots arrayed at equal intervals in a down track direction, and a read/write head which uses a plurality of adjacent magnetic dot lines as one track and sequentially performs read and write on the magnetic dots included in the magnetic dot lines constituting the track, in which the magnetic dots included in each of the magnetic dot lines in each track of the magnetic disk are displaced in the down track direction from the magnetic dots included in the adjacent dot line in the track depending on a possible skew angle between the read/write head and the track so that the magnetic dots are sequentially accessed by the read/write head.
    Type: Application
    Filed: October 4, 2010
    Publication date: January 27, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi Sakurai, Akira Kikitsu, Kazuto Kashiwagi
  • METHOD OF MANUFACTURING MAGNETIC RECORDING MEDIUM
    Publication number: 20110014496
    Abstract: According to one embodiment, there is provided a method of manufacturing a magnetic recording medium, including forming a first hard mask including carbon as a main component, a second hard mask including a main component other than carbon and a resist on a magnetic recording layer, contacting a stamper to the resist to transfer patterns of protrusions and recesses to the resist, removing residues in the recesses of the patterned resist, etching the second hard mask, etching the first hard mask, patterning the magnetic recording layer, and removing the first hard mask, the method further including, between etching the first hard mask and removing the first hard mask, removing the second hard mask remaining on the protrusions of the first hard mask, and removing a contaminating layer on a surface of the first hard mask by a mixed gas of oxygen-based gas and a fluorine compound.
    Type: Application
    Filed: July 16, 2010
    Publication date: January 20, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kaori KIMURA, Yousuke ISOWAKI, Yoshiyuki KAMATA, Masatoshi SAKURAI
  • Magnetic Recording Media, Magnetic Recording Apparatus, and Method for Manufacturing Magnetic Recording Media
    Publication number: 20110011830
    Abstract: A magnetic recording media includes a toroidal substrate, a surface thereof is divided into a recording area located in a central part between an outer peripheral edge and an inner peripheral edge, edge areas located within 100 ?m or more and 2,000 ?m or less from the outer and inner peripheral edges, respectively, and adjacent areas located between the edge areas and the recording area, respectively, a magnetic film on the substrate, and a protective film on the magnetic film, in which the magnetic film is thinner in the edge areas than that in the adjacent areas, and at least a part of the protective film in the edge areas is thicker than that in the adjacent areas.
    Type: Application
    Filed: September 27, 2010
    Publication date: January 20, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Masatoshi Sakurai, Akira Kikitsu, Yoshiyuki Kamata, Kaori Kimura
  • METHOD OF MANUFACTURING MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING MEDIUM
    Publication number: 20110000880
    Abstract: According to one embodiment, a method of manufacturing a magnetic recording medium includes forming a resist on a magnetic recording layer, imprinting a stamper to the resist to transfer patterns of protrusions and recesses, and partially etching the magnetic recording layer in areas not covered with patterns of the resist used as masks by ion beam etching using a mixed gas of He and N2 as well as modifying a remainder of the magnetic recording layer to leave behind a nonmagnetic layer having a reduced thickness.
    Type: Application
    Filed: September 14, 2010
    Publication date: January 6, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Kamata, Kaori Kimura, Yousuke Isowaki, Masatoshi Sakurai
  • STAMPER MANUFACTURING METHOD
    Publication number: 20100314253
    Abstract: According to one embodiment, a three dimensional structure of a stamper is subject to etch by supplying a pulsed electric currentelectric current to the surface of the stamper.
    Type: Application
    Filed: June 11, 2010
    Publication date: December 16, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takuya SHIMADA, Shinobu SUGIMURA, Yoshiyuki KAMATA, Masatoshi SAKURAI
  • Magnetic disk apparatus
    Patent number: 7848046
    Abstract: According to one embodiment, there is provided a magnetic disk apparatus having a magnetic disk having magnetic dot lines each including magnetic dots arrayed at equal intervals in a down track direction, and a read/write head which uses a plurality of adjacent magnetic dot lines as one track and sequentially performs read and write on the magnetic dots included in the magnetic dot lines constituting the track, in which the magnetic dots included in each of the magnetic dot lines in each track of the magnetic disk are displaced in the down track direction from the magnetic dots included in the adjacent dot line in the track depending on a possible skew angle between the read/write head and the track so that the magnetic dots are sequentially accessed by the read/write head.
    Type: Grant
    Filed: June 28, 2007
    Date of Patent: December 7, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masatoshi Sakurai, Akira Kikitsu, Kazuto Kashiwagi
  • Patterned media and method of manufacturing the same, and magnetic recording apparatus
    Publication number: 20100302679
    Abstract: A patterned media has a substrate, and a magnetic recording layer on the substrate including protruded magnetic patterns and a nonmagnetic material filled in between the protruded magnetic patterns. In the patterned media, a depth Db and a depth Da, which are defined that Db is a depth from a surface of the magnetic patterns to a surface of the nonmagnetic material filled in a first central part between the magnetic patterns adjacent to each other in a cross-track direction or a down-track direction, and Da is a depth from a surface of the magnetic patterns to a surface of the nonmagnetic material filled in a second central part in a portion surrounded by the magnetic patterns, have a relationship that the depth Da is greater than the depth Db.
    Type: Application
    Filed: August 2, 2010
    Publication date: December 2, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Kamata, Masatoshi Sakurai, Satoshi Shirotori, Kaori Kimura
  • Imprinting method and stamper
    Patent number: 7833458
    Abstract: According to one embodiment, an imprinting method includes applying a resist to a substrate, imprinting a stamper on which protruded patterns are formed against the resist applied to the substrate, forcing a distal end of a peeling wedge into a part between the substrate and the stamper, and introducing a gas between the substrate and the stamper to peel off the stamper from the substrate, in which a gap between the substrate and the stamper is made larger than a thickness of the resist at a part into which the distal end of the peeling wedge is forced.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: November 16, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akiko Yuzawa, Seiji Morita, Shinobu Sugimura, Masatoshi Sakurai
  • Magnetic recording medium with thicker protective film in edge areas and magnetic recording apparatus using the medium
    Patent number: 7826176
    Abstract: A magnetic recording media includes a toroidal substrate, a surface thereof is divided into a recording area located in a central part between an outer peripheral edge and an inner peripheral edge, edge areas located within 100 ?m or more and 2,000 ?m or less from the outer and inner peripheral edges, respectively, and adjacent areas located between the edge areas and the recording area, respectively, a magnetic film on the substrate, and a protective film on the magnetic film, in which the magnetic film is thinner in the edge areas than that in the adjacent areas, and at least a part of the protective film in the edge areas is thicker than that in the adjacent areas.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: November 2, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoshi Shirotori, Masatoshi Sakurai, Akira Kikitsu, Yoshiyuki Kamata, Kaori Kimura
  • MAGNETIC RECORDING APPARATUS, MAGNETIC RECORDING MEDIUM, AND METHOD OF TESTING MAGNETIC RECORDING APPARATUS
    Publication number: 20100271726
    Abstract: According to one embodiment, a magnetic recording apparatus includes a magnetic recording medium including magnetically recordable recording tracks with a width L1, non-recording sections each provided between adjacent recording tracks, and a wide land track having a width L2 larger than the width L1 of the recording tracks, and a head slider including read and write heads.
    Type: Application
    Filed: April 23, 2010
    Publication date: October 28, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi SAKURAI, Kazuto KASHIWAGI
  • METHOD AND APPARATUS FOR MANUFACTURING MAGNETIC RECORDING MEDIA
    Publication number: 20100264019
    Abstract: According to one embodiment, a method for manufacturing a magnetic recording medium includes forming patterns having protrusions and recesses of a ferromagnetic material onto a recording track section and a servo section on a substrate, forming a flattening film, a top surface of which is higher than that of the protrusion of the ferromagnetic material, onto the ferromagnetic material, and performing ion beam etching onto the flattening film up to a top surface of the protrusion of the ferromagnetic material, and determining an end point of flattening etching on the basis of a change in the total number of incident particles by means of an ion counter installed so as to be at an angle ? with respect to a perpendicular direction to the substrate in accordance with a material of the flattening film.
    Type: Application
    Filed: July 2, 2010
    Publication date: October 21, 2010
    Applicants: KABUSHIKI KAISHA TOSHIBA, SHOWA DENKO K.K.
    Inventors: Yoshiyuki Kamata, Katsuyuki Naito, Akira Kikitsu, Masatoshi Sakurai, Masahiro Oka
  • IMPRINTING APPARATUS
    Publication number: 20100260885
    Abstract: According to one embodiment, an imprinting apparatus includes a first mold configured to hold a disk-shaped stamper on which patterns of recesses and protrusions are formed, a second mold configured to hold a disk-shaped substrate to which a resist is applied so that the substrate faces the stamper held by the first mold, and a suction ring which is disposed around the first mold and in which an inner groove and an outer groove are formed to correspond to an outer periphery portion of the stamper held by the first mold, the inner groove being opened to atmosphere and the outer groove being vacuum-suctioned.
    Type: Application
    Filed: April 9, 2010
    Publication date: October 14, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryouichi TAKAHASHI, Satoshi SHIROTORI, Tsuyoshi ONITSUKA, Yoshiyuki KAMATA, Masatoshi SAKURAI
  • METHOD FOR MANUFACTURING STAMPER
    Publication number: 20100258523
    Abstract: According to one embodiment, an injection-molded recess and protrusion pattern surface of a resin stamper is subjected to a dry etching process for surface treatment.
    Type: Application
    Filed: April 7, 2010
    Publication date: October 14, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yasuaki Ootera, Masatoshi SAKURAI
  • Substrate for magnetic recording medium, magnetic recording medium, and magnetic recording apparatus
    Publication number: 20100247974
    Abstract: It is possible to improve the recording and reproducing S/N ratio, the reproduction signal intensity, and the degree of high density recording. There are provided a plurality of recording tracks formed on a substrate, each recording track being formed of a magnetic material, and non-recording sections formed on the substrate, each non-recording section separating adjacent recording tracks, each recording track including a plurality of recording sections and connecting sections for connecting the recording sections adjacent thereto in a track longitudinal direction, and each connecting section having a cross-sectional area in a track width direction that is smaller than a cross-sectional area in a track width direction of adjacent recording sections.
    Type: Application
    Filed: June 2, 2010
    Publication date: September 30, 2010
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Masatoshi Sakurai, Akira Kikitsu, Yoshiyuki Kamata, Satoshi Shirotori, Hiroyuki Hieda
  • Method and apparatus for manufacturing plate-like structure
    Patent number: 7803304
    Abstract: A method for manufacturing a plate-like structure, the method including a step of transferring concave and convex patterns on a master to a surface of a transferred substrate by sandwiching the master provided with the concave and convex patterns and the transferred substrate, between a press surface of a hollow cylindrical upper and a press surface of a lower mold, and pressurizing central parts of the upper and lower molds to apply pressure to the master and the transferred substrate, wherein a compressive load imposed on inner peripheral portions of the upper and lower molds is blocked and distributed toward outer peripheries of the upper and lower molds.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: September 28, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryoichi Takahashi, Masatoshi Sakurai