Patents by Inventor Hiroshi Tomiyasu

Hiroshi Tomiyasu 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: 8257783
    Abstract: In a magnetic disk including a magnetic layer, a protecting layer and a lubricating layer on a substrate, the lubricating layer is formed by a self assembly monolayer. A material of the self assembly monolayer is a hydrocarbon-based silane agent or a partial fluorinated hydrocarbon-based silane agent. The magnetic layer and the protecting layer (P) are sequentially formed on the substrate, and then the substrate on which the magnetic layer and the protecting layer (P) are formed is immersed in a solution containing the hydrocarbon-based silane agent or the partial fluorinated hydrocarbon-based silane agent, and thus a lubricating layer (L) is formed on the protecting layer (P).
    Type: Grant
    Filed: March 29, 2007
    Date of Patent: September 4, 2012
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Kota Suzuki, Hiroshi Tomiyasu
  • Patent number: 7833641
    Abstract: Disclosed is a magnetic disk which has a lubricant layer with excellent heat resistance and high adhesiveness and is free from fly-stiction failure or corrosion failure even at an extremely low flying height of 10 nm or lower. Also disclosed is a magnetic disk which has a lubricant layer with good thermal properties and can exert a stable action over a wide temperature range. The magnetic disk comprises a substrate (1), and a magnetic layer (3), a carbon-containing protective layer (4) and a lubricant layer (5) provided on the substrate (1), wherein the lubricant layer (5) contains a magnetic disk lubricant comprising a compound having a phosphazene ring and two or more hydroxyl and/or carboxyl groups in the molecule.
    Type: Grant
    Filed: January 22, 2007
    Date of Patent: November 16, 2010
    Assignee: WD Media (Singapore) Pte. Ltd.
    Inventors: Hiroshi Tomiyasu, Koichi Shimokawa
  • Publication number: 20090023017
    Abstract: Disclosed is a magnetic disk which has a lubricant layer with excellent heat resistance and high adhesiveness and is free from fly-stiction failure or corrosion failure even at an extremely low flying height of 10 nm or lower. Also disclosed is a magnetic disk which has a lubricant layer with good thermal properties and can exert a stable action over a wide temperature range. The magnetic disk comprises a substrate (1), and a magnetic layer (3), a carbon-containing protective layer (4) and a lubricant layer (5) provided on the substrate (1), wherein the lubricant layer (5) contains a magnetic disk lubricant comprising a compound having a phosphazene ring and two or more hydroxyl and/or carboxyl groups in the molecule.
    Type: Application
    Filed: January 22, 2007
    Publication date: January 22, 2009
    Applicant: HOYA CORPORATION
    Inventors: Hiroshi Tomiyasu, Koichi Shimokawa
  • Patent number: 7420886
    Abstract: There is disclosed a magnetic recording medium in which a seed layer, under layer, intermediate layer, first magnetic layer, nonmagnetic layer, second magnetic layer, protective layer, and lubricant layer are successively laminated on a glass substrate, the nonmagnetic layer is constituted of an alloy containing Cr and C, and the magnetic layer is constituted of an alloy containing Co and Pt. The under layer includes at least the seed layer for finely dividing the crystal particles of the magnetic layer, the seed layer includes at least two or more layers of nonmagnetic films, and the intermediate layer formed of the material different from that of the nonmagnetic film is interposed between the nonmagnetic films. In measurement of the thermal stability of the magnetic recording medium, a head is used, the head includes a read/write element, and a write track width is twice or more as large as a read track width in the head.
    Type: Grant
    Filed: April 20, 2007
    Date of Patent: September 2, 2008
    Assignee: Hoya Corporation
    Inventors: Hiroshi Tomiyasu, Teiichiro Umezawa, Genshichi Hata, Takashi Morikawa, Masato Kobayashi, Masashi Suzuki, Satoshi Yokota, Tsuyoshi Watanabe
  • Publication number: 20070248844
    Abstract: There is disclosed a magnetic recording medium in which a seed layer, under layer, intermediate layer, first magnetic layer, nonmagnetic layer, second magnetic layer, protective layer, and lubricant layer are successively laminated on a glass substrate, the nonmagnetic layer is constituted of an alloy containing Cr and C, and the magnetic layer is constituted of an alloy containing Co and Pt. The under layer includes at least the seed layer for finely dividing the crystal particles of the magnetic layer, the seed layer includes at least two or more layers of nonmagnetic films, and the intermediate layer formed of the material different from that of the nonmagnetic film is interposed between the nonmagnetic films. In measurement of the thermal stability of the magnetic recording medium, a head is used, the head includes a read/write element, and a write track width is twice or more as large as a read track width in the head.
    Type: Application
    Filed: April 20, 2007
    Publication date: October 25, 2007
    Inventors: Hiroshi Tomiyasu, Teiichiro Umezawa, Genshichi Hata, Takashi Morikawa, Masato Kobayashi, Masashi Suzuki, Satoshi Yokota, Tsuyoshi Watanabe
  • Patent number: 7220500
    Abstract: There is disclosed a magnetic recording medium in which a seed layer, under layer, intermediate layer, first magnetic layer, nonmagnetic layer, second magnetic layer, protective layer, and lubricant layer are successively laminated on a glass substrate, the nonmagnetic layer is constituted of an alloy containing Cr and C, and the magnetic layer is constituted of an alloy containing Co and Pt. The under layer includes at least the seed layer for finely dividing the crystal particles of the magnetic layer, the seed layer includes at least two or more layers of nonmagnetic films, and the intermediate layer formed of the material different from that of the nonmagnetic film is interposed between the nonmagnetic films. In measurement of the thermal stability of the magnetic recording medium, a head is used, the head includes a read/write element, and a write track width is twice or more as large as a read track width in the head.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: May 22, 2007
    Assignee: Hoya Corporation
    Inventors: Hiroshi Tomiyasu, Teiichiro Umezawa, Genshichi Hata, Takashi Morikawa, Masato Kobayashi, Masashi Suzuki, Satoshi Yokota, Tsuyoshi Watanabe
  • Patent number: 7220446
    Abstract: There are disclosed an information recording medium substrate having a surface roughness of Rmax 15 nm or less, and an information recording medium, particularly an information recording medium substrate and information recording medium in which for surfaces of the substrate and medium, a bearing area value (offset bearing area value) in a depth of 0.5 to 5 nm (predetermined slice level) from a bearing height (real peak height) corresponding to the bearing area value of 0.2% to 1.0% is 90% or less, and a manufacture method of the substrate and medium.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: May 22, 2007
    Assignee: Hoya Corporation
    Inventors: Tomotaka Yokoyama, Hiroshi Tomiyasu, Masatomo Shibui, Nobuyuki Eto
  • Patent number: 7208236
    Abstract: In a magnetic recording medium which comprises a substrate (1), a magnetic layer (3) formed on the substrate, a carbon-based protection layer (4) comprising carbon and formed on the magnetic layer, and a lubrication layer (5) formed on the carbon-based protection layer, the carbon-based protection layer comprises a hydrogenated carbon protection layer (4a) facing the magnetic layer and a nitrogenated carbon protection layer (4b) facing the lubrication layer. The hydrogenated carbon protection layer (4a) comprises carbon and hydrogen. The nitrogenated carbon protection layer (4b) includes no hydrogen but comprises carbon and nitrogen.
    Type: Grant
    Filed: May 6, 2005
    Date of Patent: April 24, 2007
    Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.
    Inventors: Takashi Morikawa, Teiichiro Umezawa, Hiroshi Tomiyasu, Masafumi Ishiyama
  • Patent number: 7127589
    Abstract: A data processor capable of executing sequential processing efficiently while retaining the advantages of a prior art data-driven processor.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: October 24, 2006
    Assignee: Semiconductor Technology Academic Research Center
    Inventors: Hiroaki Nishikawa, Hiroshi Tomiyasu, Ryosuke Kurebayashi, Shinya Ito, Shouhei Nomoto
  • Publication number: 20060185244
    Abstract: A novel process of producing gas fuel is provided, in which low quality fuel such as coal and various kinds of plastics and resins (polymeric compounds) collected as flame retardant waste are decomposed to gas in supercritical water, so that the resultant gas is effectively utilized as fuel. That is, polymeric compounds and aromatic/condensed-aromatic hydrocarbons are decomposed in supercritical water with ruthenium oxide (IV) as a catalyst. The resultant gas components through the decomposition are collected as gas fuel.
    Type: Application
    Filed: February 4, 2004
    Publication date: August 24, 2006
    Inventors: Ki Park, Hiroshi Tomiyasu
  • Publication number: 20050208341
    Abstract: In a magnetic recording medium which comprises a substrate (1), a magnetic layer (3) formed on the substrate, a carbon-based protection layer (4) comprising carbon and formed on the magnetic layer, and a lubrication layer (5) formed on the carbon-based protection layer, the carbon-based protection layer comprises a hydrogenated carbon protection layer (4a) facing the magnetic layer and a nitrogenated carbon protection layer (4b) facing the lubrication layer. The hydrogenated carbon protection layer (4a) comprises carbon and hydrogen. The nitrogenated carbon protection layer (4b) includes no hydrogen but comprises carbon and nitrogen.
    Type: Application
    Filed: May 6, 2005
    Publication date: September 22, 2005
    Inventors: Takashi Morikawa, Teiichiro Umezawa, Hiroshi Tomiyasu, Masafumi Ishiyama
  • Patent number: 6946191
    Abstract: In a magnetic recording medium which comprises a substrate (1), a magnetic layer (3) formed on the substrate, a carbon-based protection layer (4) comprising carbon and formed on the magnetic layer, and a lubrication layer (5) formed on the carbon-based protection layer, the carbon-based protection layer comprises a hydrogenated carbon protection layer (4a) facing the magnetic layer and a nitrogenated carbon protection layer (4b) facing the lubrication layer. The hydrogenated carbon protection layer (4a) comprises carbon and hydrogen. The nitrogenated carbon protection layer (4b) includes no hydrogen but comprises carbon and nitrogen.
    Type: Grant
    Filed: February 24, 2003
    Date of Patent: September 20, 2005
    Assignees: Hoya Corporation, Hoya Magnetics Singapore PTE
    Inventors: Takashi Morikawa, Teiichiro Umezawa, Hiroshi Tomiyasu, Masafumi Ishiyama
  • Patent number: 6916558
    Abstract: In a magnetic disk having a glass substrate, an amorphous underlayer is formed on the glass substrate. A magnetic layer is formed on the amorphous underlayer. The glass substrate is provided with a texture formed to induce magnetic anisotropy in the magnetic layer. The amorphous underlayer contains a group IVa element on a glass substrate side and a group Va element on a magnetic layer side.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: July 12, 2005
    Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.
    Inventors: Teiichiro Umezawa, Hiroshi Tomiyasu, Keiji Moroishi
  • Publication number: 20050076188
    Abstract: A data processor capable of executing sequential processing efficiently while retaining the advantages of a prior art data-driven processor.
    Type: Application
    Filed: September 30, 2004
    Publication date: April 7, 2005
    Applicant: Semiconductor Technology Academic Research Center
    Inventors: Hiroaki Nishikawa, Hiroshi Tomiyasu, Ryosuke Kurebayashi, Shinya Ito, Shouhei Namoto
  • Patent number: 6852010
    Abstract: A substrate for an information recording medium has a microwaviness average height Ra? not greater than 0.05 microinch as measured by a contactless laser interference technique for measurement points within a measurement region of 50 ?m?-4 mm? on a surface of the substrate. The microwaviness average height Ra? is given by: Ra ? = 1 n ? ? i = 1 n ? ? | xi - x _ | , where xi represents a measurement point value of each measurement point, {overscore (x)} representing an average value of the measurement point values, n representing the number of said measurement points. Alternatively, the substrate has a waviness period between 300 ?m and 5 mm and a waviness average height Wa of 1.0 nm or less as measured by the contactless laser interference technique for measurement points in a measurement region surrounded by two concentric circles which is spaced from a center of a surface of the substrate by a predetermined distance.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: February 8, 2005
    Assignee: Hoya Corporation
    Inventors: Kouji Takahashi, Takemi Miyamoto, Hiroshi Tomiyasu, Genshichi Hata, Tomotaka Yokoyama
  • Patent number: 6790509
    Abstract: A substrate for an information recording medium, wherein the period of microwaviness is 2 &mgr;m to 4 mm, and if we let wa be the maximum height of this microwaviness and Rmax be the maximum height measured by atomic force microscope, the main surface of the substrate has a wa of no more than 5 nm and an Rmax of no more than 12 nm, provided that wa is the difference between the highest and lowest points on a measurement curve of all measured points in a measurement area.
    Type: Grant
    Filed: October 4, 2001
    Date of Patent: September 14, 2004
    Assignee: Hoya Corporation
    Inventors: Tomotaka Yokoyama, Takemi Miyamoto, Hiroshi Tomiyasu, Kouji Takahashi
  • Publication number: 20040170870
    Abstract: There are disclosed an information recording medium substrate having a surface roughness of Rmax 15 nm or less, and an information recording medium, particularly an information recording medium substrate and information recording medium in which for surfaces of the substrate and medium, a bearing area value (offset bearing area value) in a depth of 0.5 to 5 nm (predetermined slice level) from a bearing height (real peak height) corresponding to the bearing area value of 0.2% to 1.0% is 90% or less, and a manufacture method of the substrate and medium.
    Type: Application
    Filed: January 20, 2004
    Publication date: September 2, 2004
    Applicant: Hoya Corporation
    Inventors: Tomotaka Yokoyama, Hiroshi Tomiyasu, Masatomo Shibui, Nobuyuki Eto
  • Publication number: 20040161577
    Abstract: In a magnetic disk having a glass substrate, an amorphous underlayer is formed on the glass substrate. A magnetic layer is formed on the amorphous underlayer. The glass substrate is provided with a texture formed to induce magnetic anisotropy in the magnetic layer. The amorphous underlayer contains a group IVa element on a glass substrate side and a group Va element on a magnetic layer side.
    Type: Application
    Filed: February 17, 2004
    Publication date: August 19, 2004
    Applicants: HOYA CORORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.
    Inventors: Teiichiro Umezawa, Hiroshi Tomiyasu, Keiji Moroishi
  • Patent number: 6759138
    Abstract: In a magnetic recording medium which includes a base body (1-4), first and second magnetic layers (5 and 7), each being of a ferromagnetic material, and a spacer layer (6) formed between the first and the second magnetic layers for inducing antiferromagnetic exchange interaction between the first and the second magnetic layers, the second magnetic layer located farther from the base body than the first magnetic layer includes a primary layer (72) and a secondary layer (71) located nearer to the base body than the primary layer. The primary layer has a primary anisotropic magnetic field while the secondary layer has a secondary anisotropic magnetic field which is smaller than the primary anisotropic magnetic field. The first magnetic layer is for controlling the antiferromagnetic exchange interaction.
    Type: Grant
    Filed: July 2, 2002
    Date of Patent: July 6, 2004
    Assignees: Hoya Corporation, Hoya Magnetics Singapore PTE, Ltd.
    Inventors: Hiroshi Tomiyasu, Keiji Moroishi, Teiichiro Umezawa, Kenji Ayama
  • Patent number: 6706427
    Abstract: There are disclosed an information recording medium substrate having a surface roughness of Rmax 15 nm or less, and an information recording medium, particularly an information recording medium substrate and information recording medium in which for surfaces of the substrate and medium, a bearing area value (offset bearing area value) in a depth of 0.5 to 5 nm (predetermined slice level) from a bearing height (real peak height) corresponding to the bearing area value of 0.2% to 1.0% is 90% or less, and a manufacture method of the substrate and medium.
    Type: Grant
    Filed: December 20, 2000
    Date of Patent: March 16, 2004
    Assignee: Hoya Corporation
    Inventors: Tomotaka Yokoyama, Hiroshi Tomiyasu, Masatomo Shibui, Nobuyuki Eto