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).
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Patent number: 8257783Abstract: 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: GrantFiled: March 29, 2007Date of Patent: September 4, 2012Assignee: WD Media (Singapore) Pte. Ltd.Inventors: Kota Suzuki, Hiroshi Tomiyasu
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Patent number: 7833641Abstract: 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: GrantFiled: January 22, 2007Date of Patent: November 16, 2010Assignee: WD Media (Singapore) Pte. Ltd.Inventors: Hiroshi Tomiyasu, Koichi Shimokawa
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Publication number: 20090023017Abstract: 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: ApplicationFiled: January 22, 2007Publication date: January 22, 2009Applicant: HOYA CORPORATIONInventors: Hiroshi Tomiyasu, Koichi Shimokawa
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Patent number: 7420886Abstract: 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: GrantFiled: April 20, 2007Date of Patent: September 2, 2008Assignee: Hoya CorporationInventors: Hiroshi Tomiyasu, Teiichiro Umezawa, Genshichi Hata, Takashi Morikawa, Masato Kobayashi, Masashi Suzuki, Satoshi Yokota, Tsuyoshi Watanabe
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Publication number: 20070248844Abstract: 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: ApplicationFiled: April 20, 2007Publication date: October 25, 2007Inventors: Hiroshi Tomiyasu, Teiichiro Umezawa, Genshichi Hata, Takashi Morikawa, Masato Kobayashi, Masashi Suzuki, Satoshi Yokota, Tsuyoshi Watanabe
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Patent number: 7220500Abstract: 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: GrantFiled: March 31, 2000Date of Patent: May 22, 2007Assignee: Hoya CorporationInventors: Hiroshi Tomiyasu, Teiichiro Umezawa, Genshichi Hata, Takashi Morikawa, Masato Kobayashi, Masashi Suzuki, Satoshi Yokota, Tsuyoshi Watanabe
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Patent number: 7220446Abstract: 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: GrantFiled: January 20, 2004Date of Patent: May 22, 2007Assignee: Hoya CorporationInventors: Tomotaka Yokoyama, Hiroshi Tomiyasu, Masatomo Shibui, Nobuyuki Eto
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Patent number: 7208236Abstract: 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: GrantFiled: May 6, 2005Date of Patent: April 24, 2007Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.Inventors: Takashi Morikawa, Teiichiro Umezawa, Hiroshi Tomiyasu, Masafumi Ishiyama
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Patent number: 7127589Abstract: A data processor capable of executing sequential processing efficiently while retaining the advantages of a prior art data-driven processor.Type: GrantFiled: September 30, 2004Date of Patent: October 24, 2006Assignee: Semiconductor Technology Academic Research CenterInventors: Hiroaki Nishikawa, Hiroshi Tomiyasu, Ryosuke Kurebayashi, Shinya Ito, Shouhei Nomoto
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Publication number: 20060185244Abstract: 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: ApplicationFiled: February 4, 2004Publication date: August 24, 2006Inventors: Ki Park, Hiroshi Tomiyasu
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Publication number: 20050208341Abstract: 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: ApplicationFiled: May 6, 2005Publication date: September 22, 2005Inventors: Takashi Morikawa, Teiichiro Umezawa, Hiroshi Tomiyasu, Masafumi Ishiyama
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Patent number: 6946191Abstract: 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: GrantFiled: February 24, 2003Date of Patent: September 20, 2005Assignees: Hoya Corporation, Hoya Magnetics Singapore PTEInventors: Takashi Morikawa, Teiichiro Umezawa, Hiroshi Tomiyasu, Masafumi Ishiyama
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Patent number: 6916558Abstract: 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: GrantFiled: February 17, 2004Date of Patent: July 12, 2005Assignees: Hoya Corporation, Hoya Magnetics Singapore Pte. Ltd.Inventors: Teiichiro Umezawa, Hiroshi Tomiyasu, Keiji Moroishi
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Publication number: 20050076188Abstract: A data processor capable of executing sequential processing efficiently while retaining the advantages of a prior art data-driven processor.Type: ApplicationFiled: September 30, 2004Publication date: April 7, 2005Applicant: Semiconductor Technology Academic Research CenterInventors: Hiroaki Nishikawa, Hiroshi Tomiyasu, Ryosuke Kurebayashi, Shinya Ito, Shouhei Namoto
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Patent number: 6852010Abstract: 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: GrantFiled: January 16, 2003Date of Patent: February 8, 2005Assignee: Hoya CorporationInventors: Kouji Takahashi, Takemi Miyamoto, Hiroshi Tomiyasu, Genshichi Hata, Tomotaka Yokoyama
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Patent number: 6790509Abstract: 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: GrantFiled: October 4, 2001Date of Patent: September 14, 2004Assignee: Hoya CorporationInventors: Tomotaka Yokoyama, Takemi Miyamoto, Hiroshi Tomiyasu, Kouji Takahashi
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Publication number: 20040170870Abstract: 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: ApplicationFiled: January 20, 2004Publication date: September 2, 2004Applicant: Hoya CorporationInventors: Tomotaka Yokoyama, Hiroshi Tomiyasu, Masatomo Shibui, Nobuyuki Eto
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Publication number: 20040161577Abstract: 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: ApplicationFiled: February 17, 2004Publication date: August 19, 2004Applicants: HOYA CORORATION, HOYA MAGNETICS SINGAPORE PTE. LTD.Inventors: Teiichiro Umezawa, Hiroshi Tomiyasu, Keiji Moroishi
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Patent number: 6759138Abstract: 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: GrantFiled: July 2, 2002Date of Patent: July 6, 2004Assignees: Hoya Corporation, Hoya Magnetics Singapore PTE, Ltd.Inventors: Hiroshi Tomiyasu, Keiji Moroishi, Teiichiro Umezawa, Kenji Ayama
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Patent number: 6706427Abstract: 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: GrantFiled: December 20, 2000Date of Patent: March 16, 2004Assignee: Hoya CorporationInventors: Tomotaka Yokoyama, Hiroshi Tomiyasu, Masatomo Shibui, Nobuyuki Eto