Patents by Inventor Tsuyoshi Onitsuka

Tsuyoshi Onitsuka 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: 20180122417
    Abstract: A magnetic recording medium includes a substrate and a stacked film on the substrate and including a magnetic recording layer. An elastic modulus Esub of the substrate satisfies Equation (1) below, where h is a film thickness of the stacked film and Efilm is an Young's modulus of the stacked film: Esub?(200*Efilm)/(6*h)??(1).
    Type: Application
    Filed: February 28, 2017
    Publication date: May 3, 2018
    Inventors: Akira WATANABE, Tomoki UMETSU, Tsuyoshi ONITSUKA, Hiroyuki HYODO
  • Publication number: 20170062001
    Abstract: According to one embodiment, a method of evaluating a scratch mark includes, for a magnetic recording medium including a magnetic recording layer containing magnetic particles and a metal oxide grain boundary provided between the magnetic particles, detecting and evaluating a scratch mark based on information about the reflection intensity of light in a predetermined wavelength range. The predetermined wavelength range includes at least a second wavelength range from 600 nm to 700 nm and a first wavelength range from 300 nm to 500 nm.
    Type: Application
    Filed: December 23, 2015
    Publication date: March 2, 2017
    Inventors: Akira Watanabe, Tsuyoshi Onitsuka, Hiroyuki Hyodo
  • Publication number: 20160158790
    Abstract: A tool for dip-coating a disc-shaped substrate having a through hole therein includes a support member having a portion made of a porous material, that is to be inserted into the through hole and support the disc-shaped substrate during the dip-coating. Further, a method for dip-coating a disc-shaped substrate having a through hole therein, includes supporting the substrate on a portion of a tool, the portion being made of a porous material, submerging the substrate and the tool into a dip coating liquid, and taking the substrate and the tool out of the dip coating liquid.
    Type: Application
    Filed: June 15, 2015
    Publication date: June 9, 2016
    Inventors: Akira WATANABE, Tsuyoshi ONITSUKA
  • Publication number: 20160027461
    Abstract: A method for forming a particle layer includes covering surfaces of particles with a first polymer, covering a surface of a substrate with a second polymer having a same skeletal structure as the first polymer, and applying a liquid in which the particles covered with the first polymer are dispersed, onto the surface of the substrate covered with the second polymer.
    Type: Application
    Filed: November 20, 2014
    Publication date: January 28, 2016
    Inventors: Akira WATANABE, Kaori KIMURA, Tsuyoshi ONITSUKA
  • Patent number: 8995089
    Abstract: According to one embodiment, there is provided a magnetic recording medium which includes a base, a magnetic recording layer having convex-shaped magnetic layers, which is formed on the base, and a protective film formed on the magnetic recording layer. There are gaps in a region surrounded by the protective film, the surface of the base, and each side wall of each magnetic layer.
    Type: Grant
    Filed: July 17, 2013
    Date of Patent: March 31, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Masahiro Takashita, Akihiko Takeo
  • Patent number: 8858809
    Abstract: A manufacturing method of a magnetic recording medium includes steps of forming a magnetic recording layer, a first mask layer, a second mask layer containing silicon as primary component, a strip layer, a third mask layer, and a resist layer, a step of patterning the resist layer to provide a pattern, steps of transferring the pattern to the third mask layer, to the strip layer, and to the second mask layer, a step of removing the strip layer by wet etching and of stripping the third mask layer and the resist layer above the magnetic recording layer, steps of transferring the pattern to the first mask layer and to the magnetic recording layer, and a step of stripping the first mask layer remaining on the magnetic recording layer.
    Type: Grant
    Filed: September 7, 2012
    Date of Patent: October 14, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Akira Watanabe, Kaori Kimura, Kazutaka Takizawa, Takeshi Iwasaki, Tsuyoshi Onitsuka, Akihiko Takeo
  • Publication number: 20140248513
    Abstract: According to one embodiment, there is provided a method for producing a magnetic recording medium which includes forming a mask layer on a magnetic recording layer, applying metal fine particles on the mask layer, covering the metal fine particles with an overcoat layer, irradiating with energy beams through the overcoat layer so as to deactivate a protective coating of the metal fine particles, transferring a metal fine particle pattern from the mask layer to the magnetic recording layer, and removing the mask layer from the magnetic recording layer.
    Type: Application
    Filed: July 12, 2013
    Publication date: September 4, 2014
    Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Akihiko Takeo
  • Publication number: 20140247519
    Abstract: According to one embodiment, there is provided a magnetic recording medium which includes a base, a magnetic recording layer having convex-shaped magnetic layers, which is formed on the base, and a protective film formed on the magnetic recording layer. There are gaps in a region surrounded by the protective film, the surface of the base, and each side wall of each magnetic layer.
    Type: Application
    Filed: July 17, 2013
    Publication date: September 4, 2014
    Inventors: Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Tsuyoshi Onitsuka, Takeshi Iwasaki, Masahiro Takashita, Akihiko Takeo
  • Publication number: 20140147701
    Abstract: A magnetic recording medium is manufactured by forming a magnetic recording layer on a substrate, forming a protective layer on the magnetic recording layer, executing a sputtering process using a target containing a first ingredient and a second ingredient to form on the protective layer a grain-state mask layer that includes grains formed of the first ingredient and grain boundaries between the grains formed of the second ingredient, etching the grain boundaries so that a projection pattern of the grains is formed, and transferring the projection pattern of the grains to the magnetic recording layer.
    Type: Application
    Filed: April 23, 2013
    Publication date: May 29, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Takeshi IWASAKI, Kazutaka TAKIZAWA, Akira WATANABE, Kaori KIMURA, Tsuyoshi ONITSUKA
  • Patent number: 8652338
    Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: February 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Tsuyoshi Onitsuka
  • Publication number: 20130248485
    Abstract: A manufacturing method of a magnetic recording medium includes steps of forming a magnetic recording layer, a first mask layer, a second mask layer containing silicon as primary component, a strip layer, a third mask layer, and a resist layer, a step of patterning the resist layer to provide a pattern, steps of transferring the pattern to the third mask layer, to the strip layer, and to the second mask layer, a step of removing the strip layer by wet etching and of stripping the third mask layer and the resist layer above the magnetic recording layer, steps of transferring the pattern to the first mask layer and to the magnetic recording layer, and a step of stripping the first mask layer remaining on the magnetic recording layer.
    Type: Application
    Filed: September 7, 2012
    Publication date: September 26, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akira Watanabe, Kaori Kimura, Kazutaka Takizawa, Takeshi Iwasaki, Tsuyoshi Onitsuka, Akihiko Takeo
  • Publication number: 20130180948
    Abstract: According to one embodiment, a release layer is formed on a magnetic recording layer, a mask layer is formed on the release layer, projecting patterns are formed on the mask layer, the projecting patterns are transferred onto the mask layer, the projecting patterns are transferred onto the release layer, the projecting patterns are transferred onto the magnetic recording layer, the release layer is removed by a solvent, and a remaining mask layer is removed from the surface of the magnetic recording layer. The release layer is made of a polymeric material. The mask layer is made of at least one of a metal or a metal compound. The projecting patterns are formed by using a self-organized layer made of a block copolymer having at least two of polymer chains.
    Type: Application
    Filed: July 27, 2012
    Publication date: July 18, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazutaka TAKIZAWA, Akira WATANABE, Kaori KIMURA, Takeshi IWASAKI, Tsuyoshi ONITSUKA, Akihiko TAKEO
  • Publication number: 20130075358
    Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.
    Type: Application
    Filed: November 15, 2012
    Publication date: March 28, 2013
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kaori KIMURA, Yoshiyuki KAMATA, Satoshi SHIROTORI, Tsuyoshi ONITSUKA
  • Patent number: 8338007
    Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: December 25, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Tsuyoshi Onitsuka
  • Publication number: 20120087039
    Abstract: According to one embodiment, a magnetic recording medium includes a substrate, and a magnetic recording layer formed on the substrate. The magnetic recording layer includes recording portions having patterns regularly arranged in an longitudinal direction and containing cobalt and platinum, and non recording portions formed between the recording portions and containing boron and at least one light rare earth metal selected from the group consisting of yttrium, lanthanum, and cerium.
    Type: Application
    Filed: June 20, 2011
    Publication date: April 12, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takeshi Iwasaki, Kaori Kimura, Yoshiyuki Kamata, Tsuyoshi Onitsuka, Masatoshi Sakurai
  • 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
  • Publication number: 20090161257
    Abstract: According to one embodiment, a magnetic recording medium includes protruded magnetic patterns formed on a substrate, and a non-magnetic material filled in recesses between the magnetic patterns and made of a multi-element amorphous alloy containing Ni or Cu, and two or more metals selected from the group consisting of Ta, Nb, Ti, Zr, Hf, Cr, Mo and Ag.
    Type: Application
    Filed: March 9, 2009
    Publication date: June 25, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akiko Yuzawa, Masatoshi Sakurai, Yoshiyuki Kamata, Satoshi Shirotori, Kaori Kimura, Tsuyoshi Onitsuka
  • Publication number: 20090081482
    Abstract: A magnetic recording medium a magnetic recording medium includes a soft magnetic layer formed on a substrate, magnetic patterns made of a protruded ferromagnetic layer separated from each other on the soft magnetic layer, and a nonmagnetic layer formed between the magnetic patterns, a nitrogen concentration therein being higher on a surface side than on a substrate side.
    Type: Application
    Filed: September 26, 2008
    Publication date: March 26, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kaori Kimura, Yoshiyuki Kamata, Satoshi Shirotori, Tsuyoshi Onitsuka
  • Publication number: 20080318085
    Abstract: A method of forming a carbon protective film is disclosed that improves electromagnetic conversion characteristics through reduction of the film thickness without any damage on a magnetic layer. Also disclosed is a magnetic recording medium that exhibits good electromagnetic conversion characteristics and corrosion resistance. The method of forming the carbon protective film uses a high frequency plasma CVD method on a disk including at least a magnetic film on a nonmagnetic substrate. A bias voltage in a range of ?200 V to zero V is applied at the beginning of discharge in a process of forming the carbon protective film, and a bias voltage in a range of ?500 V to ?200 V is applied at the end of discharge. Also disclosed is a magnetic recording medium having at least a magnetic film and a protective film on a nonmagnetic substrate, wherein the protective film is formed by the method of forming a protective film stated above according to the invention.
    Type: Application
    Filed: June 11, 2008
    Publication date: December 25, 2008
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Tuqiang LI, Masaki MIYAZATO, Tsuyoshi ONITSUKA, Makoto ISOZAKI, Hajime KURIHARA
  • Patent number: 6667116
    Abstract: A magnetic recording medium which includes a non-magnetic base layer having layered upon it, in sequence, a non-magnetic middle layer and a magnetic layer. The magnetic layer has ferromagnetic crystal grains surrounded by non-magnetic grain boundaries. The non-magnetic middle layer is formed of a non-magnetic oxide or nitride, and is disposed between the non-magnetic base layer and the magnetic layer. The non-magnetic oxide or nitride in the middle layer forms a fine, island-like film. At the time of film formation of the granular magnetic layer on the middle layer, this island-like film performs stationing for the ferromagnetic crystal grains and the growth nucleus for the non-magnetic grain boundary. As a result, fine dispersion of the ferromagnetic crystal grains in the granular magnetic layer is hastened, and a high coercivity is obtained even with a small Pt composition ratio. The available reduction in Pt composition ratio reduces the cost of the magnetic recording medium.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: December 23, 2003
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Hiroyuki Uwazumi, Akira Saito, Tsuyoshi Onitsuka, Tadaaki Oikawa